Single crystal diamond material

FIELD: chemistry.

SUBSTANCE: invention relates to technology of obtaining single crystal diamond material for electronics and jewellery production. Method includes growing single crystal diamond material by method of chemical precipitation from vapour or gas phase (CVD) on main surface (001) of diamond substrate, which is limited by at least one rib <100>, length of said at least one rib <100> exceeds the longest surface dimension, which is orthogonal to said at least one rib <100>, in ratio at least 1.3:1, and single crystal diamond material grows both on the normal to the main surface (001) and sideward from it, and during CVD process value α constitutes from 1.4 to 2.6, where α=(√3×growth rate in <001>) ÷ growth rate in <111>.

EFFECT: invention makes it possible to obtain larger in area diamond materials with low density of dislocations.

14 cl, 8 dwg, 3 ex

 

The present invention relates to a method of growing single crystal diamond material by chemical vapor deposition from the vapor or gas phase (CVD) and, in fact, grown by CVD diamond material.

Diamond material has a number of unique properties, including light transmittance, conductivity, hardness, wear resistance and its electronic properties. While many of the mechanical properties of the diamond material can occur in more than one type of the diamond material, other properties are very sensitive to the type of the diamond material. For some applications, for example, to the best of the electronic properties, the use of single-crystal diamond material grown by the CVD method may be preferred because it can surpass the polycrystalline diamond material grown by the CVD method, the diamond material made famous by high pressure and high temperature (HPHT), and natural diamond.

Growing single-crystal diamond material by a CVD method typically includes the growing diamond material homoepitaxial on the existing diamond plate. This process is termed "homoepitaxially CVD synthesis" and is well known in the prior art. Typically, it includes the pod is in the camera different quantities of gases, including a carbon source, the excitation of gases and provide conditions under which creates carbon plasma over an existing diamond plate, on which are deposited the carbon atoms from the plasma, forming a diamond material. Usually the existing diamond plate serving as the main substrate on which the method of CVD grown diamond material is a natural diamond material or cut out, or is a manufactured by the method of HPHT diamond plate or cut from it. Usually this existing diamond plate placed on polictial, usually made of molybdenum, tungsten, silicon or silicon carbide, in the chamber for growing a CVD method.

Diamond core substrate typically includes a first main face, which is designed for growth and for growth. The term "face", we mean a surface that is flat or almost flat. The face on which growth occurs, is called the term "facet growth" main substrate. Typically, though not necessarily, the main substrate is a plate that includes a second main face that is mainly parallel to the first principal face and separated therefrom perpendicular distance, which is the thickness of the layer is Ki, moreover, the above-mentioned thickness of the plate is typically less, usually substantially less than the transverse dimensions of the main faces. The second main face provides a convenient means of installing the main substrate to the first main face provided the growth process. The main distinction is that, where you can find two lying in the face orthogonal dimensions, a and b (a≥b), which, compared to any two orthogonal dimensions in any other face, a1and b1(a1≥b1), to satisfy the requirement (a≥a1) and (b≥b1). In the present description, two measurements are approximately equal, when less is within 5% of the larger.

The facet growth found in nature and produced by HPHT major diamond substrates may be of any shape. When we talk about the shape of the face of the growth of diamond core substrate, I mean two-dimensional contour of the face formed by the peripheral surface and the peripheral surface formed by the intersection of other surfaces with surface growth. Grown by the method of HPHT diamond core substrate may, for example, be rectangular in shape, having four ribs <100>. Used here, the term "rectangular" includes the square. Alternatively, grown by the method of HPHT diamond core mean the CA may, for example, to be octagonal, with four ribs <100>, separated by the four parties <110>that may have the same or a different length compared to edges <100>. Sometimes the corners or edges of naturally occurring diamonds or grown by the method of HPHT diamond core substrate may be damaged or missing. Typically, naturally occurring diamonds or grown by the method of HPHT diamond core substrate suitable for use as substrates for CVD are the main face of the growth, where each dimension is a few millimeters, for example, the shortest and the longest dimension in the range from 1 to 8 mm

In the known processes CVD face of the main growth substrate may have a different crystallographic orientation. The most common orientation, which is used for growing high-quality CVD diamond material is typically a plane defined by the Miller indices (001). Throughout the present description the Miller indices {hkl}, define a plane based on the x, y and z, will be given in the assumption that the z-direction is normal or rejected within 15°, or within 10°, or within 6°, or within 3° from the normal to the face of the growth of the main substrate and parallel to the direction of growth. Then x and y have the be in the plane of the face of the growth of the main substrate, and as a rule, are equivalent by symmetry.

During homoepitaxial growth of single crystal material formed during growth on any particular crystallographically oriented surface, usually termed the "pyramid of growth" (or "growth sector") for a given surface. For example, the material formed during growth on the surface of (001), called the pyramid growth (001).

During cultivation method, CVD diamond material is homoepitaxially growth of the single crystal from the main surface growth (typically, this surface is (001)). This growth is not only normal to the surface of the main growth substrate, but may also occur sideways from her. Thus, when there is growth, there is thickening grown by CVD diamond layer, and the lateral extension of the grown diamond layer relative to the main diamond substrate. Lateral growth can represent the same pyramid growth as the main surface growth (in the normal case, is the pyramid of the growth of (001)), which then increases the area of the side surface relative to the surface area of the main growth substrate. Alternatively, the lateral growth may represent other pyramids growth, such as {113}. Does the lateral growth so is th same pyramid growth or other pyramid growth on the main surface of the growth, depends on growth conditions.

In addition homoepitaxial growth of the single crystal from the main surface of the growth, there is also homoepitaxially growth of the single crystal from the side surfaces of the main substrate. Thus, for the typical case where the surface of the growth represents the surface (001), growth occurs not only on the faces (001), but also on the lateral surfaces, which may, in the case of square or rectangular surface, to represent, for example, the surface {100}. The growth of the single crystal diamond is generally continuous across the boundary of the pyramid growth between areas of growth, formed by different facets of growth.

US6096129 describes a method of growing diamond material on the surface of the substrate so that the grown diamond material has a larger area than the original substrate. This document describes the software source single-crystalline diamond base material, on which a single crystal diamond material homoepitaxial precipitated from the vapor phase, resulting in a diamond material, which is cut and polished, getting the following basic material, which again is grown monocrystalline material, resulting in a single-crystal diamond material having a large area. How best pok is given the examples in figures 4A-4C US6096129, the original key material is almost square with the side surfaces of {100}, and the growth occurs mainly on the upper surface of the {001}, and the above-mentioned growth is sideways, as well as normal from the upper surface of the {001}, so that the surface of the growth has increased the lateral (transverse) dimensions compared to the dimensions of the original base material. The subsequent main material cut from the grown diamond material is a square in cross section. Side of a square rotated by 45° relative to the sides of the base material, and it has rib <110>. Area of square section subsequent base material is less than twice the area of the square section base material due to the "offensive" faces {111} in the grown diamond material. This subsequent main material is then used for further growth, and that further growth occurs from the edges of <110>. The preferred ratio of growth rates of α (which is determined by the relation [√3 × growth rate in the <001>]÷[the growth rate in the <111>]) are components of at least 3:1.

WO 2004/027123 (Element Six Ltd) describes an alternative method of obtaining a plate of single-crystal diamond material of the CVD diamond material grown apologice, moreover grown plate may be larger than the original substrate. The method involves separation grown by the method of homoepitaxial CVD diamond material and the substrate on which it was grown across the surface of the substrate on which the growth of the diamond material, to obtain a plate of single crystal CVD diamond material.

The first aspect of the present invention provides a method of growing single crystal diamond material, including:

(a) providing a first diamond substrate, which has a main surface (001), and this main surface is limited to at least one edge of <100>length mentioned at least one edge <100> greater than any dimension of the surface, which is orthogonal mentioned at least one edge <100>in a ratio of at least 1.3:1; and

(b) growing diamond material homoepitaxial on the main surface of the (001) surface of the diamond material under the conditions of synthesis by chemical vapor deposition from the vapor or gas phase (CVD), and diamond material grows as normal to the main surface of the (001)and sideways from her.

According to the method according to the present invention, the first diamond substrate provides a base substrate, providing for the growth of the main face (surface is th growth). Surface growth is a surface (001), which has at least one edge, forming part of the periphery of the surface growth, which is essentially linear and is oriented along the direction of <100> and is longer than any other perpendicular dimension lying within the surface of the growth (and, thus, the direction <100>), in a ratio of greater than 1.3 to 1, which, in the alternative, the record as a 1.3. When we say that it is at least one edge <100> greater than "any" other perpendicular dimension, we mean "each and every" another dimension, perpendicular to the aforementioned at least one edge. Thus, it is at least one edge in the direction <100> greater than the length of at least 1.3 times the longest dimension (referred to the surface)perpendicular to this at least one edge <100>.

The ratio of the length of this at least one edge <100> (the substrate surface) to its longest perpendicular dimension is called in the present description the term "aspect ratio" of the surface. This term is used regardless of the shape of the surface of the substrate. For a rectangular substrate surface with lengths of sides a and b (where a>b) the aspect ratio is a/b. The correlation with the Oron used in the method according to the invention the first substrate, of at least 1.3:1, significantly bosire than the substrates used in the previously described processes of growing a CVD method where, as a rule, used substrates with square faces (i.e. with an aspect ratio equal to 1).

Preferably, the first substrate provides for the growth of the main face that has at least 3 edges, forming a part of the periphery of the surface of the growth, where each of these ribs is substantially linear and oriented along directions <100> or <110>. Preferably, the first substrate provides for the growth of the main face that has at least 4 edges, forming a part of the periphery of the surface growth, including two parallel pairs of orthogonal ribs <100>. Preferably, these two parallel pairs of orthogonal ribs <100> are all present in the ribs.

As noted above, we call the aspect ratio used in the method according to the invention the first substrate against the ribs (usually the longest edge), forming part of the periphery of the surface growth, which is essentially linear and is oriented along the direction of <100>, perpendicular to the longest dimension lying in the plane of the face of growth (and hence also the direction <100>). This is the aspect ratio according to our invented the Yu is at least 1.3 to 1.

The aspect ratio of the first substrate according to the present invention is at least 1.3:1 and preferably higher than 1.3:1, or greater than 1.5:1, or exceed 1.7:1, or greater than 2:1, or greater than 2.5:1, or greater than 3:1, or greater than 4:1, and may even exceed 5:1 or more.

The first substrate may be in the form of a plate, in which the second main surface parallel to the main surface, forming a surface growth, and the second major surface forms the back face of the substrate. Alternatively, the rear face (faces) of the first substrate may be a more complex geometry. For convenience, the following links will usually attributed to the special geometry of the plate, but it should be noted that in its broadest aspect the present invention includes circumstances in which the other surface of the substrate, in addition to the main faces forming surface growth, do not include the second main face that is parallel to the surface of the growth.

Referred to the line determined by such expressions and terms of the main surface of the (001)" or "main line for growth (surface growth), which represents the surface of the {001}", can be a surface having an orientation, which is exactly (001), which mainly, but it can also be a surface where the holes of the al to the surface deviates by up to 15°, preferably up to 10°, preferably 6°C, most preferably up to 3°, to the direction [001]. Similarly, the reference directions <100>, lying in the plane of the main surface (001), can mean not just <100>, but the nearest direction corresponding to the direction <100>, which does not lie in the plane of the main surface and which deviates not more than 15°, preferably not more than 10°, preferably not more than 6°, most preferably not more than 3°, the direction <100>.

When we talk about growing sideways from the main surface of the growth, it is understood that such lateral growth is associated with a vertical height from the main surface of the growth (by which we mean a growth normal to the main surface of the growth), i.e. the lateral growth of the pyramid growth of the main surface is associated with thickening of the pyramid growth. Single crystal diamond material grown by the CVD method according to the first aspect of the invention, defined for convenience in the present description as having two separate areas as follows: the material that extends above the plane of the surface of the substrate on which the growth and beyond the peripheral boundaries of the original substrate (when viewed along the direction normal to the main face of the growth substrate), nativestring scope lateral growth"; and the material that extends above the original substrate (i.e. enclosed within the peripheral bounds of the original substrate, when viewed along the direction normal to the main face of the growth substrate), termed "the epigastric region growth". This area lateral growth can be distinguished from any stretching sideways growth, resulting from the deposition of carbon directly on the side surfaces of the first diamond substrate during the CVD process, since it lies above (i.e. in the direction of growth) plane, a particular source main face of the growth.

The object formed by the cultivation method of the CVD diamond material on the first substrate, herein described as "grown by CVD diamond material. Alternatively, it can be called "grown by CVD diamond stone."

The present invention represents a departure from the prior art and acknowledges for the first time that under certain conditions the synthesis method of CVD-grown CVD diamond material with an increased lateral (transverse) dimensions compared to the dimensions of the original substrate can be obtained from the base substrate having the surface growth with a higher aspect ratio (in accordance with the above discussion and definition than that used previously, in particular, with sootnoshenie the m to the parties at least 1.3:1. It is recognized that under appropriate conditions the use of this source substrate is neither harmful nor problematic. Up to the present time the usual practice was to use the largest available source of substrates, or, if you had a cut, then cut out the greatest potential of the substrate, in which the two largest orthogonal dimensions <100>, lying in the plane of the main surface growth are close, i.e. their ratio is significantly less than 1.3:1. More typically used in the prior art substrates were essentially square, i.e. had an aspect ratio equal to 1, sometimes with one or more missing corners.

In a preferred embodiment, the implementation provided (taken) the first diamond substrate has a main surface (001), and this main surface is limited to at least one edge of <100>, and the method includes growing diamond material homoepitaxial on the main surface of the (001) diamond material, and the growth continues in one or more stages until, until a sufficient thickness of the grown diamond material to the associated lateral growth of the diamond material is large enough to achieve the full effective rotation of said main surface (001) diamond material.

The achievement fully what about the effective rotation of said main surface (001) diamond material we mean, what side of said main surface is (001), limited in the source substrate mentioned at least one edge of <100>, limited in-grown substrate in two orthogonal edges <110>, which intersect each other and which cover and replace the whole line, the source specific mentioned at least one edge of <100>. This is illustrated below by the example of rectangular and triangular source substrates.

In a preferred embodiment of the invention said main surface is (001) diamond substrate has two adjacent and intersecting ribs <100>and the full effective rotation of said main surface (001) diamond material leads to the formation of three ribs <110>, which cover and replace the two edges <100>, and these two edges <110> are parallel to each other and orthogonal to the third edge of the <110>. The third rib <110> lies between them and, when projected onto the plane defined main face of the growth of the source of the first substrate, or touches the point of intersection of the original ribs <100>or shifted sideways outward from this point of intersection due to lateral growth.

In another preferred embodiment of the invention said main surface is (001) is limited to the first substrate only four ribs <100>, and the total effective surface to the mouth of said main surface (001) diamond material leads to the formation of four ribs < 110> in the form of two parallel pairs that are orthogonal to each other, which cover all four edges <100> of the first substrate. Every edge <110>, when projected onto the plane defined main face of the growth of the original substrate or touches the corresponding one of the four intersection points of the original ribs <100> (of the face angles of the growth substrate), or shifted sideways outward from these points of intersection due to lateral growth, forming end-grown diamond material having a main surface growth, which is essentially square.

Used herein, the terms "edge <100>" and "the edge of <110>" include ribs, which accurately represent the ribs of <100> and ribs <110>, respectively, which are predominant, as well as edges that slant up to 15°, preferably 10°, preferably 6°C, most preferably up to 3°, directions <100> and <110>, respectively.

This achievement full effective rotation of said main surface of the diamond material in the preferred implementation is a departure from the method of the prior art, described in US6096129, not only because the first diamond substrate has a larger aspect ratio, as described here, but also because in the method described in this publication ur is VNA equipment, does not fully effective rotation that was not the purpose in the prior art. It does not occur as a result of the faces {111} on the main face (001) grown diamond material.

In preferred methods according to the invention is grown diamond material has a main surface (001) with a surface area that is at least 200%, preferably 220%, preferably at least 250%, preferably 270%, even more preferably 300%, the area of said main surface, the main surface (001) of the first substrate.

In some embodiments of the invention, the first diamond substrate used in the method according to the first aspect of the invention, is almost rectangular, preferably having an aspect ratio of at least 1.3:1 or greater than 1.3 to 1. That is, the first substrate is a rectangle with sides a and b, where a/b≥1,3. For certain variants of realization of the invention the first diamond substrate may be substantially rectangular, having an aspect ratio that is preferably greater than 1.5:1, or exceed 1.7:1, or greater than 2:1, or greater than 2.5:1, or greater than 3:1, or greater than 4:1, or greater than 5:1.

For those variants of realization, where the first substrate is rectangular, the main surface of the substrate predpochtitel is about is the main surface of {001}, in particular, the main surface is (001), preferably with ribs <100>.

In other embodiments of the invention, the first diamond substrate is almost triangular, and preferably has a main surface (001). Preferably, almost triangular main surface is a rectangular triangle, which is preferably limited to at least one edge of <100> and one edge of <110>, preferably one edge of <100> and two ribs <110>or two edges <100> and one edge of <110>.

In those preferred embodiments of, where is the full effective rotation for almost rectangular first substrate, for example, for a substrate with edges parallel to the [100] and [010], and lateral dimensions a × b (where a is bigger than b), "full effective rotation is achieved when sufficient lateral growth of the diamond material occurred in the pyramid growth (001) so that the grown diamond material has an upper surface (001), which is almost square in cross section, the axis of symmetry of the upper surface of the (001) grown diamond material rotated by an angle of 45° relative to the axis of symmetry of the rectangular main surface (001) of the first substrate. For these preferred variants of implementation, with the full effective rotation, Vakata the upper surface of the (001) grown diamond material is limited to faces, parallel to the directions [110] and [110], and as can be calculated by geometry, has lateral dimensions (a+b)/√2×(a+b)/√2.

The first substrate is, as a rule, natural diamond or synthesized by the method of HPHT diamond material, although they can also be grown by CVD diamond material. Such substrate in a commercially available form may be uneven or irregular in shape. For example, synthesized by the method of HPHT diamond material (which is usually made approximately square shape) is common that one or more corners synthesized by the method of HPHT diamond material is damaged or even missing. These have uneven or irregular shape natural or synthetic diamond materials can be used to provide suitable first substrate to the present invention, first cutting a part of the correct form of the original parts of irregular shape. Therefore, the preferred embodiment of the invention includes an initial stage of providing a diamond substrate precursor, for example, having the uneven shape of the diamond substrate with the main surface (001), and circumcision with an uneven shape of the diamond substrate to form a minority who she least one rib < 100> on the main surface of the (001), and preferably cut inscribed rectangular diamond substrate from the diamond substrate predecessor, and inscribed rectangular substrate cut out having ribs <100>. In geometry it can be shown that the area of the square ohranenii surface grown from a rectangular substrate with lengths of sides a and b, is set as 0.5(a+b)2. Thus, this area reaches its maximum at the maximum value of (a+b). Therefore, in the preferred implementation according to the invention is inscribed rectangular wafer cut from a wealthy (for example, having an uneven or irregular shape) of the substrate predecessor, carved with maximizing the value of a+b, where a and b represent, respectively, long and short sides of a rectangular substrate, and this cut is inscribed rectangular substrate provides mentioned the first diamond substrate in the method according to the first aspect of the present invention. It will be clear that you may need to trim some or all of the sides of the diamond substrate precursor for optimal inscribed rectangular substrate, is used as the first substrate in the present invention. Similarly, for any three-dimensional piece of diamond material, which is still n the was prepared in the form of plates, the preferred surface is {100}, which is chosen to form and which will form the surface (001) of the base substrate, is the one that gives the substrate greatest sum of a+b, where a and b represent the sizes of the two orthogonal pairs of ribs <100>, completely restricting the main face of the substrate. For example, this rule can be used to select the height of the diamond material, which form the major surface.

Similarly, another preferred embodiment of the present invention includes an initial stage of providing a diamond substrate, for example, having the uneven shape of the diamond substrate with the main surface (001), and cutting inscribed triangular diamond substrates that are irregular in shape diamond substrate predecessor, with carved inscribed triangular diamond substrate provides the above-mentioned "first substrate" in the method according to the first aspect of the invention. Cut an inscribed triangle should be cut with at least one edge <100>.

Thus, the present invention allows it to be used as source material for growing method, a CVD single crystal diamond material such substrates, which could hitherto be rejected for the reason that ed is stenny square, which could be cut from this substrate was recognised too small to be suitable for use. The ability to take with uneven or irregular shape plate (001) and use it according to the present invention leads to a significant increase of the useful use of a commercially available material of the substrate.

In other embodiments of the invention having an uneven or irregular, or even equal, or the correct form of the substrate, for example, square or rectangular substrate can be cut into any number of smaller correct forms, for example, for n equal rectangles or triangles, where n is more than 1 more than 2 more than 3 and so on, even up to 8 or more, thus gaining "first substrate"used in the method according to the first aspect of the invention. If the data is correct shapes are rectangles, the preferred aspect ratio are more than 2, 3 and even up to 8. If you cut out a rectangular plate, they preferably gabriny <100>. If you cut out the triangles, they preferably have at least one edge <100> and at least one rib <110>. From a single substrate can be cut to any combination of rectangles and triangles, satisfying predpochtitel the diversified requirements to the ribs.

In those preferred embodiments of where a substrate precursor to cut n rectangular substrates (where n>1), cut a rectangular substrate may be the same or different in size. One measurement (one size) - cut substrates may be the same or smaller compared to one dimension (size) of the substrate predecessor.

In preferred methods according to the invention each of the n rectangular substrates are used as the first substrate in the method according to the invention, and each of the grown diamond material has a main surface (001), and the total area mentioned main surfaces (001) n grown diamond material exceeds by at least 20%, preferably 50%, preferably 100%, most preferably 200%, the area of the diamond material grown from the substrate predecessor, if it is not cut and grown to full effective rotation with the main surface (001).

In certain embodiments of the invention, a square base with side length a is cut into n equal rectangular substrates, where n>1, can be more than 2 or 3, or even up to 8, and each rectangle preferably has a long side length a and the short side length a/n, all edges of the growth surfaces preferably p is establet a < 001>. Each cut a rectangle provides a "first substrate"used in the method according to the first aspect of the invention.

In other embodiments of the invention, a square base with side length a is cut into unequal rectangular substrate, preferably with ribs <001>, each cut a rectangle provides a "first substrate"used in the method according to the first aspect of the invention.

Square substrate, which is cut with the correct form of the substrate, for example, rectangular or triangular substrate may be a commercially available diamond material or may be a having a square face diamond material grown by the full effective rotation of the other of the diamond material. Thus, the invention provides for the cycle "growth-cutting-growth" for the preparation of the diamond material.

The advantage of these implementation options, in which the correct substrate is cut into two or more smaller substrates correct form, is that it is possible to boost the growth of the total area grown by CVD diamond plates compared to the area increase, which would have been achieved if the substrate for growth used the original uncut substrate.

<> The preferred embodiment according to the present invention includes (a) cutting a section of the diamond material from the area of the lateral growth of the grown single-crystal diamond substrate (grown on the first stage of the synthesis) so that the cross-section cut of the diamond material provides a surface (001) with edge <100>, and (b) (the second stage of synthesis) growing diamond material homoepitaxial on the surface (001) cut a section of the diamond.

The advantage of this variant implementation is that when the lateral growth tends to have a much lower density of dislocations than in the epigastric growth (as described later in the description), and, therefore, the diamond material grown from the cut cross section of lateral growth, also has a low dislocation density, which makes it particularly suitable for those applications where the desired low density of defects. For example, it is known that dislocations cause stress, which affects the optical homogeneity of the material, if it is used in the optical element. In addition, it is known that dislocations associated traps in the forbidden energy band of the material, which affects its own media properties, and this means that crystal diamond grown with low defect density, is especially for the serious for applications in electronics. In these preferred embodiments of where the section cut out from a lateral growth in the first stage of synthesis for use in the second stage of the synthesis, the cut of the diamond material lateral growth provides almost triangular or rectangular surface (001).

Another embodiment according to the invention includes the location of two or more rectangular substrates, each of which has a main surface (001) and at least one rib <100>, next to each other so as to provide a continuous edge <100>, which exceeds the length of the longest edge <100> any of the mentioned two or more rectangular substrates. Located close to the substrate is called a "mosaic" of the substrate, and growing a CVD method from a mosaic of substrates derived from the continuous ribs <100>. These two or more substrates are preferably rectangular, preferably with an aspect ratio of at least 1.3 to 1. They preferably have end to end with their long edges combined to ensure the continuous ribs <100>.

Discovered that best strict control of process parameters to achieve the full effective rotation from the first substrate with an aspect ratio of at least 1.3 to 1. One parameter that can be monitored in the process versiani the method CVD single crystal diamond material and which is well known in the art for the synthesis of diamond material by a CVD method, is the so-called "parameter α". The parameter α is proportional to the ratio of the growth rate (GR) in the direction of the <001> the growth rate in the direction <111> and is defined as: α=√3×(GR <001>)÷(GR <111>).

In preferred embodiments of the invention the desired parameter α is preferably in the range from 1.4 to 2.6, preferably in the range from 1.6 to 2.4, more preferably in the range from 1.8 to 2.2 and for some variants of realization in the range from 1.9 to 2.1.

In the known methods CVD parameter α, as is known, varies between <1 and >3, and the value of α depends, among others, from the set of synthesis conditions on the site, including conditions of pressure, temperature and gas flow, and to a lesser extent from the hardware parameters, such as vessel-reactor for CVD. It is known that the parameter α is calculated after completion of the synthesis, conducting measurements on newly grown diamond materials and using simple geometric relations and crystallographic data for the calculation of α. In the technique is also known, the mapping parameter α" specific synthesis reactor by measuring the diamond material grown in a number of combinations of pressure, temperature and gas composition, again with the help of measurements after the fact. Methodology characterization of the alpha parameter for some data the first set of conditions is widely described, however, particularly useful is the work of Silva (Silva) and others, Diamond &Related Materials 18 (2009), 683-697. Silva and others describe how to choose the temperature, gas pressure, power and the chemistry of the process (for example, the amount of gaseous methane, oxygen, nitrogen, hydrogen, argon, and so on) to achieve specified values of α, including the value of α in our preferred range from 1.8 to 2.2. The exact values of each of these properties are specific to the used Silva reactors (since, as is known in the art, α also depends on the reactor), but a specialist will be able to easily describe any other reactor and to choose appropriate values for each of the above properties, using information Silva, etc. in order to achieve the desired α parameter.

According to the present invention, in preferred implementations, we offer a combination of the method of synthesis and the synthesis reactor, which is stable and sufficiently well characterized to be able to decide a priori that a particular value of α (or a narrow range of values of α) can be set before the beginning of the synthesis, and then get the crystals with the desired α, due to the characteristic according to the methodology described in the publication Silva.

We found that the selection of conditions of synthesis by CVD method,for example, when growing method, CVD diamond material with α in the above preferred range, the rate of growth in the [001] direction is relatively high compared with the rate of growth in the direction <111>to practically prevent the formation of facets of {111} directly below and next to the main surface of the growth of (001), and just low enough to really interfere with the main surface growth (001) become unstable and form bumps and/or other harmful features. We found that, ceteris paribus, if α is above the preferred range, the facet {111} are formed and can sdavatsa, so these twins come to the main face of the growth of (001) and thereby delay or stop any further increase in the lateral size of the grown crystal. Similarly, we found that, ceteris paribus, if α is below the preferred range, the lateral growth is limited and loss of smooth growth on the surface (001).

Single crystal diamond material grown by the methods according to the invention, will have two distinct areas - the area of the lateral growth region epigastric growth, as defined above. We observed that these two different areas may differ in their concentration of extended defects, and the lateral area of the river is one hundred and typically contains a much lower concentration of extended defects, than the epigastric region growth. The term "extended defect" means a defect, such as one or more of the dislocation, which occurs at the point (usually in or on the surface of the first substrate) and then distributed into the growing crystal (typically approximately in the direction of growth). The relative proportions of extended defects in these two areas can be determined by methods such as the measurement of the electronic properties, measurement of double refraction methods of etching and other optical methods, which allow to compare the density of defects. Consider that the difference between the densities of extended defects in the lateral areas and the epigastric growth is due to the fact that in the diamond material dislocations are usually held in the growth areas of the <100> or close to it. Inasmuch as the lateral growth directly under it is the substrate to provide a surface for propagation of dislocations in the direction of growth <100>area lateral growth has improved crystallinity (lower dislocation density than the epigastric area growth (which is directly above the substrate).

In addition, we observed that the field side and the epigastric growth are usually separated by a high density of dislocations, which occurs somewhere in the grown crystal. Consider h is about this high density of dislocations occurs from the edges of the source substrate. This area with a high density can be detected by methods such as double refraction, and optical birefringence investigate, using such devices as "Metripol" (Oxford Cryosystems UK), transmission electron microscopy (TEM) and x-ray topography.

As an example, it was found that the dislocation density in CVD diamond material in the epigastric region growth is typically in the range of 103-105cm-2, while in the area of the lateral growth, it may be <500 cm-2. Near the border between the epigastric region growth and the area of the lateral growth of the dislocation density is typically in the range of 103-106cm-2and, usually from ten to one hundred times higher than their density in the adjacent area of the epigastric growth.

Almost square grown by CVD diamond material or virtually any diamond wafer cut from grown by CVD diamond material that has been grown from the first substrate with edge <100> and the aspect ratio (as defined above) of at least 1.3:1, in particular, that (that), (AE) includes such an array of dislocations in the layout corresponding to the shape of the surface of the first growth substrate, indicating the growing CVD method of the first substrate with edge <100> and the aspect ratio (as defined is Elena above) at least 1.3:1, is new in itself.

The second aspect of the present invention provides for the grown diamond material having practically grown square surface, which was grown by the CVD method from the main surface (001) of the first diamond substrate and the main surface (001) of the first diamond substrate was limited to at least one edge of <100>, and the length of the mentioned at least one edge <100> exceeding any dimension (surface), which was orthogonal mentioned at least one edge <100>in a ratio of at least 1.3:1.

Typically, the grown diamond material includes dislocation. They usually arise at the edges of the surface growth of the first diamond substrate and distributed through the diamond material in the direction of growth, i.e. almost in the direction of the <001>. Therefore, in the grown diamond there are many rows of dislocations extending almost in the direction of the <001>. These rows of dislocations, thus, represent a "record" in the grown diamond contour of the original substrate. As a rule, dislocation occurs in some but not all points along the edges of the surface growth of the first diamond substrate. There may be sections without dislocations, as well as section with a certain number of dislocations. Given the initial orientation the first substrate, these dislocations, as a rule, extend in rows, usually in the planes (100) and (010), or in planes within 15° from these planes. When projected on the plane (001) each row of dislocations is a point, and if you connect the dots, they form a line or a line (or a segment or segments) in the direction of the edges (edges) of the first diamond substrate. Thus formed lines correspond to the shape and size of the contour surface of the first growth of the diamond substrate.

When we speak in the present description, the line or line segment or segments)formed by connecting the dots (which represent the projection of the rows of dislocations on the plane (001)), define the contour of the surface growth, we consider the possibility that the line does not actually intersect, but they continue intersect each other. Possible this is the case, for example, that there is no number of dislocations propagating from one or more corners of the first substrate, and in this case, the continuation lines (segments) intersect and, thus, define the contour of the angle(s). As a rule, any line connecting points along either side of the substrate, will extend along at least 50%, preferably along at least 60%, or 70%, or 80% of the length of a side of the first substrate.

In one embodiment, the implementation of the grown diamond material is grown from the first diamond substrate, which had a rectangular surface with an aspect ratio of at least 1.3:1, and grown diamond substrate includes multiple rows of dislocations, each of which normally extends generally in the direction of the <001>, or within 15°, or within 10°, or within 6°, or within 3° from this direction, and which when projected on the plane (001) give points, which when connected form two pairs of parallel lines or line segments that form a rectangle and this rectangle is a "record" the position of the edges of the first diamond substrate, from which emerged a series of dislocations.

In another embodiment, the implementation of the grown diamond substrate grown from the first diamond substrate, which had a triangular surface (preferably the surface in the shape of a rectangular triangle) with at least one edge of <100>, and the length of the mentioned at least one edge <100> greater than any dimension of the surface, which was orthogonal mentioned at least one edge <100>in a ratio of at least 1.3:1, and grown diamond substrate includes multiple rows of dislocations, each of which normally extends into the direction of the <001>, or within 15°, 10°, 6° or 3° from this direction, and which when projected on the plane (001) make the point that when with whom the Association form a line, which intersect, forming a triangle, and the triangle is the "record" position of edges of the first diamond substrate, from which emerged a series of dislocations.

As described above, the position of the dislocations can be set with known methods.

Grown by CVD diamond, including these series of dislocations, which serve as the "entry" of the edges of the source substrate, indicating that the source substrate had an aspect ratio (as defined above) of at least 1.3 to 1, is a novel in itself.

The third aspect of the present invention provides grown by CVD diamond material that contains many rows of dislocations, with each row extends almost in the direction of the <001>, each row of dislocation when projected on the plane (001) defines a point, and these points (from the respective rows of dislocation) when connecting define a first segment extending in the direction <100>, and the second line segment intersecting the first mentioned section and extending in the direction of the <001> or <110>, and the ratio of the length of the first segment to the length of the second segment, or Vice versa, is at least 1.3:1, or it may exceed the 1.3:1, or 1.5:1, or exceed the 1.7:1, or greater than 2:1, or less than 2.5:1, or greater than 3:1, or greater than 4:1, or even greater than 5:1.

In particular the x implementations each row of dislocation when projected on the plane (001) defines a point and these points (from the respective rows of dislocation) when the connection is determined by four line segment extending in the direction <100>, and these segments form a rectangle.

In other embodiments of the invention, each row of dislocation when projected on the plane (001) defines a point, and these points (from the respective rows of dislocation) when connecting define two segments of the <100> and the segment <011>or one piece <100> and two segments of the <011>, and these segments form an isosceles right triangle.

If said point is connected, determining one or more lines or line segments are straight lines, carried out with the best fit through the mentioned point.

In preferred methods according to the invention the thickness of the first substrate typically is in the range of 0.2-1.2 mm, but is not limited to this interval.

In preferred methods according to the invention the thickness of the grown diamond material is approximately half the length of the longest edge <100> in the original substrate. Growth up to this thickness corresponds to a full rotation, as defined above. But it can also be achieved growth to a greater or lesser thickness, which may be desirable for certain applications.

Preferred methods according to the invention give MES the crystalline diamond plate, and preferred methods include the machining stage grown by the method of homoepitaxial CVD diamond material in the record.

Next, the embodiments of the invention will be described as an example with reference to the accompanying drawings, where:

figure 1 is a perspective view showing the first diamond substrate suitable for use in the methods according to the invention;

figures 2a-2e - top, showing successive stages of the process of growing a CVD method of a substrate according to figure 1;

figures 3 and 4 are views in section along the lines X and Y respectively, figure 2d;

figure 5 is a schematic view showing the distribution of dislocations during the growth process by the method of the CVD diamond material, shown in figures 2-4;

figure 6a is an optical micrograph, taken from the top view, the grown crystal diamond, the appropriate stage of growth, shown in figure 2e;

figure 6b - image double refraction sections, marked by the dotted line Z in figure 6a, taken from the top view, after removal of the source of the underlying substrate;

figure 6c is an optical micrograph, taken from the top view, another grown diamond crystal corresponding to the stages of growth are shown in figure 2e;

figure 6d - x-ray topography (RT image) {008}, shot(OE) in orientation from above through the grown crystal of the diamond in figure 6c, after removing the source of the underlying substrate;

figures 7a-7d and 8a-8d is a schematic diagram showing various methods of increasing the total area grown diamond material using the method of growing diamond material by the CVD method according to the present invention.

Referring to the drawings, figure 1 shows the first diamond substrate 1, suitable for use in the methods according to the invention. The diamond substrate 1 is almost rectangular, having a length a, width b and thickness t, where a>b>t. The dimensions of the first diamond substrate 1 are: a=5 mm, b=1 mm t=0.5 mm

The diamond substrate 1 has a main surface (001) 3, which is limited by the edges of <100> 4, and has four side surfaces {010} 5 (two of which are visible in Fig. 1). It is placed on the surface 7, which includes silicon, or any other suitable substrate, as described above, and set the camera CVD under the conditions described hereinafter with reference to the examples, and, in particular, under conditions where α (as defined above) is in the range from 1.9 to 2.1.

During the process of growing a CVD method preferential growth of single crystal is a pyramid growth (001), i.e. growth with the faces (001) 3, but there will also be some growth of the single crystal in pyramidata (100), (010) (-100), (0-10), i.e. on the side surfaces 5. In addition, there will be some contention polycrystalline growth, starting with a tungsten surface 7.

As can be seen in figures 2a-2d and figures 3 and 4, the pyramid of the growth of (001) grown diamond material extends not only along the normal to the surface (001) (i.e., parallel to the thickness t of the substrate 1 and of the sheet, if you look at the figures 2a-2d), but also sideways.

The growth of ribs <100> is faster than the growth of ribs <110>, so the lateral growth continues from the edges of <001> up until the growing surface provides edge <110>. In the first stage, as shown in figure 2a, the surface growth (001) 3 grew out sideways in the direction <100>, so that the surface growth has an octagonal shape bounded by four edges <100> 4' and four ribs <110> 6'. Therefore, there are four areas of lateral growth (that part of growth that is not directly over the face 3 of the original substrate), all of which are trapezoidal in shape, two along the long edges of the substrate 1 (hereinafter referred to as the term "ribs a") and two along the short sides of the substrate 1 (hereinafter referred to as the term "ribs b"). The degree of lateral growth g is the same from all edges of the substrate 1.

In the second stage of growth, presented in figure 2b, the surface growth grew sideways by a distance R. the main b/2, in all directions, forming a hexagonal shape surface 3" of growth, limited four ribs <110> 6" and two edges <100> 4". At this stage of the edges b of the source substrate to form a region lateral growth, which in form is a rectangular isosceles triangles, limited source b is an edge of the substrate (which forms the hypotenuse of the triangle) and a pair of mutually perpendicular directions <110>. The distance from the right angle of this triangle to the midpoint of b-edges is b/2. Ribs a source substrate at this stage form having the shape of a trapezoid the area of the lateral growth, with width b/2 and limited (i) the original ribs <100> substrate, (ii) edge <100>, parallel to the original a-edge, and (iii) a pair of ribs <110>, which are a continuation of ribs <110> lateral growth on the b-edges. At this stage of the growth surface 3" of growth twice that of the original surface 3 growth.

The next stage of growth presented in figure 2c. Since the growth of ribs <100> is substantially faster than the growth of ribs <110>, there is a small further lateral growth from the short ribs b, and instead continued growth from a long-ribs. This means that the surface 3" of growth is still hexagonal with two ribs <100> 4" and chetyre the ribs I < 110> 6", but the length of the ribs <100> 4" shorter than the length of the respective edges <100> surface 3" in figure 2b, while the length of the ribs <110> 6" greater than the length of ribs <110> 6" in figure 2b.

After reaching this stage, any slow lateral growth from the edges of <110> will, as a rule, become weaker and typically include the twinning. This further twin growth is not shown in figures 2c-2e or figures 3-5, but apparent on subsequent micrographs in figure 6, which are discussed next.

Growth continues in such a way that the ribs <110> elongated and ribs <100> shortened up until all ribs <100> will not disappear, and the corresponding pair of rising edges <110> do not cross each other. At this stage, the surface growth is a square 3IVlimited to four ribs <110> 6IVas shown in figure 2d. Pair these ribs <110> 6IVintersect each other, and lie in the plane (110), which crosses the above-mentioned rib <100> 4, the first substrate 1 under the respective corners 10 of the above-mentioned ribs <100> of the first substrate 1. At the stage shown in figure 2d, believe that happened "full effective rotation. Axis square surface 3IVgrowth rotated by 45° relative to the axis of the surface 3 of the growth of the source substrate 1.

After the stage shown in F. the góra 2d, further growth depends on growth from the edges of <110>, which is much slower than from the rib of <100>. However, in case of optimization of synthesis conditions can be achieved further lateral growth, albeit slow, with most of this growth occurs at the same rate from each edge, <110>, so that the surface of the 3Vgrowth continues to be square in shape (see figure 2e) with axes coinciding with the axes of the square surface 3IVgrowth in figure 2d, i.e. the further rotation does not occur. Thus, under favorable conditions can be achieved growth outside the provisions of the full effective rotation.

Figures 3 and 4 are views in cross section of figure 2d, drawn along lines X-X and Y-Y respectively. They show that there is a growth of a single crystal of the pyramid growth (001) 15, from the pyramid growth (010) 17 (from the side face 5 of the substrate 1) and from the pyramid growth (011) 19 (from the top of the substrate 1). Although the species in the different section of the pyramid growth of single-crystal diamond material is shaded differently for clarity, in reality they form a continuous crystal. This monocrystalline growth of 15, 17, 19 corresponds to polycrystalline growth 21 that goes from the surface 7, which is set diamond substrate 1.

Figures 3 and 4 also illustrate the difference between region 23 Bo the new growth area of 25 vertical growth as defined in the present invention above.

Figure 5 is a schematic view showing the position where they can usually take place dislocations emerging at or near the surface 3 and 5 of the substrate. The position of the dislocations are marked by dashed lines 27. Such dislocation can be made visible near the known methods, as discussed above. It will be seen that there is an area with a lower density of dislocations over the main surface of the (001) 3 the source of the diamond substrate 1, but the outside edges of the substrate, i.e. in the region 23 of the lateral growth. Diamond plate cut from the field 23 of the lateral growth can mainly be used for those applications where the desired low density of dislocations.

Figure 6a is a shot in the top view optical micrograph of the grown diamond material. It corresponds to the stage of growth discussed above are presented on figure 2e, i.e. the stage outside the full effective rotation. In figure 6a the first rectangular substrate 1 again in place and visible on the micrograph of the top view, through the overlying transparent grown crystal. Grown by CVD diamond material that has been grown out full effective rotation is almost square surface 3Vgrowth with four ribs <110> 6V. These four ribs <10> 6Vwhen projected down onto the plane of the original surface of the first growth of the source substrate 1 passes out of the corners 10 of the first substrate 1. In figure 6a reduced growth, in particular, twin growth, 31 also visible outside edges <110> 3V.

Figure 6b is an image of a double refraction produced in orientation from the top through a rectangular cross-section cut along the dotted lines Z in the figure 6a, through the entire thickness grown by CVD diamond material, but after removing the first substrate 1. Methods double refraction is used to indicate areas of tension in the crystal, and the area of higher contrast point to areas of greater voltage, and this voltage is considered relevant areas with a higher density of dislocations (or other defects).

Figure 6b shows the darker line 33, which form a rectangular shape corresponding to the shape of the original surface of the first growth substrate 1. These line 33, thus, represent evidence of planes passing through the thickness of the grown crystal from the position of the edges of the original (but now removed) of the first substrate 1, which have a higher density of dislocations (or other defects)than the surrounding area of the grown crystal.

Figure 6b also shows that the Central region is ü 35 within a rectangular array of lines 33 has more contrast than the outer region 37 outside the rectangular array of lines 33. The Central region 35 is a "base growth", as defined above and as represented by reference number 25 in figures 3-5, while the outer region 37 represents a "lateral growth", as defined above and as represented by reference number 23 in figures 3-5. This difference in contrast between regions 35 and 37 in the grown crystal is a testimony to the lower density of dislocations (or other defects)associated with the region of the lateral growth of the diamond material, compared to the epigastric region of the growth of the diamond material.

Figure 6C is a shot in the top view optical micrograph of another grown by CVD diamond material grown from a rectangular source substrate, outside of a full rotation. As in the grown diamond material according to figure 6a, the surface of the 3Vgrowth of the grown diamond material is a square with edges <110> 6Vand the diamond material was grown just outside of a full rotation. Again visible twinned region 31 outside edges <110> 6Vgrown diamond material.

Figure 6d is an XRT image {008}, skim through grown by CVD diamond material according to figure 6c, after removing the first substrate 1. Method XRT (x-ray what's topography) is an alternative method of obtaining images of double refraction which can be used to determine the scattering power inside the crystal and thus to identify heterogeneity, such as dislocations or other defects. On XRT-image areas with a higher density of defects is shown in more contrasting areas. In figure 6d dark rectangular line 39 is a certificate corresponding to the position of the edges of the surface growth of the source substrate 1, which is now being removed. Rectangular line 39, thus, indicates the planes with a higher density of defects, passing up through the grown crystal from the original perimeter surface of the first growth substrate 1.

Although the above embodiments, shown in figures 6a-6d show how you can get a certificate, illustrating the history of the growth grown by CVD diamond material, it should be recognized that existing or future methods may remove such dislocations or other defects. Therefore, the absence of any obtained by the method of double refraction or XRT image grown by CVD diamond material defects of the type described, corresponding to the edges of the source of the diamond substrate and/or epigastric and lateral growth does not necessarily mean that the method according to the present invention was not used the La-growing single-crystal diamond material.

The present invention should be compared with the above-described document of the prior art, in which, due to the used conditions, there was a tendency to the formation of surfaces of {111}. Such surfaces have an increased tendency to twinning and usually limit the degree to which the possible side growth, because the surface {111} steps on the surface of the growth.

As noted above, the rectangular plate with lateral dimensions a×b, with the top face (001) and side faces {100}, grows outward by a distance equal to b/2, forming a hexagonal shape (as shown with reference to figure 2b), i.e., to form, when fully grown short ribs b, and one set of edges, namely the long edges a, not increased. To date, the growing diamond material by the CVD method carried out, as a rule, in conditions where the surface growth (001) is extremely stable, and under such conditions, since the rectangular substrate, twinning occurs in the fully raised pyramid growth of {100} (i.e. the pyramid growth of {100}, grew out of the short ribs (b), which quickly spreads to the upper surface (001), thereby disrupting any further growth outside of the form shown in figure 2b, where one set of ribs is fully grown. In the past, because it used a square of the original substrate, the similar crystal fully grown in all lateral directions simultaneously, that is, after the growth of a/2, so the problem of twinning did not arise. In the method according to the first aspect of the present invention, where the underlying substrate is not square, and, for example, rectangular, not all the edges are fully grown at the same time, so are usually used up to the present time, would occur twinning, as only short ribs <100> of the original substrate was fully grown would, forming ribs <110> (figure 2b), and would violate any subsequent growth on the long edges <100>. By the proper choice of growth conditions other than those normally used up to the present time, we mostly managed to achieve sustainable growth beyond a distance of b/2, resulting in not only the ribs b, and a rib can fully grow, giving the grown substrate with the form shown in figure 2d, or even figure 2e.

Consider figures 7a-7c, which show the 61 square with edges <100> side "a"grown up fully rotated square with ribs 63 <110> (the first stage of synthesis). The 63 square cut along its diagonal <100> 65 (shown by hatching in the figure 7b), forming two rectangular triangle 66, each rib <100> (the hypotenuse) and the other two sides of the <110>. Each triangle 66 then used as the material source for Viridian the I of ribs < 100> to the full effective rotation to obtain a crystal with a square face 66', limited ribs <110> (the second stage of the synthesis). Therefore, during the second stage of the synthesis to the square shape 66' each of the triangular substrates source 66 is growing sideways to the General triangular section 67 growth. Triangular section 67 all represents a "lateral growth", as defined above, and a triangular section 67 lateral growth has a common hypotenuse of the triangular section 68 "base growth", which overlaps the source substrate 66. Section 67 of lateral growth and section epigastric growth in fact, represent a continuous single crystal, but section 67, as all lateral growth, will have a significantly reduced density of defects (e.g. dislocations) compared to the epigastric growth (as described above with reference to figure 5). At the third stage of the synthesis nicolerichie section 67 can be cut and used as the initial substrate with edge <100>from which when full effective rotation can be grown crystal with a square surface (001) 67'. Because in this case, the original substrate 67 is Nicodemou region, the substrate 67'grown in this third stage of the synthesis, will also contain a low number of defects. In embodiments of the figure 7, the increase in the area with whom is 100% at each stage of the synthesis. The advantage of the embodiments described with reference to figure 7, is that it allows you to get having a large area diamond materials with a low density of dislocations. For clarity, the area with low or almost zero dislocation density shown shaded in figures 7c and 7d.

Variant of implementation in figure 7 is based on the cultivation of a tripartite substrates, where the triangular substrate have one oriented <100> direction and two oriented <110> directions.

Tripartite substrate, are shown in figure 7, is made from the original square plates. Alternatively, they can be made of plates of any other shape. Similarly, although the tripartite substrate, are shown in figure 7, are isosceles triangles, you can use other triangular shape with triangles having sides of different lengths.

In a variant implementation, shown in figure 8, the first stage of the synthesis involves the cultivation of a substrate-71 square with side length a, and the square 71 has a surface growth of (001) and edge <100> (figure 8a), the lateral growth distance a/2, providing full effective rotation with education with square crystal face 73 with ribs <110> (figure 8b). This square then cut VD is eh both of its diagonals (as shown by the dashed line 75), forming four triangular part 77, each with two edges <100> and one edge of <110>. For simplicity, the figure 8c illustrates only one triangular part 77, but it will be clear that there are three similar parts, which may make growing at the second and third stages of the synthesis. In the second stage of the synthesis of each part 77 is then used for growth at a distance a/2, rectangular receiving part 79 (figure 8c). Lateral growth with part 77 gives two pieces of triangular shape 81 and 83 in figure 8c, and being all lateral growth, each of the parts 81 and 83 contains significantly fewer dislocations than the epigastric region growth. These areas of lower density of dislocations is shown shaded in the figure. Epigastric growth is indicated by 77' in figure 8c and not shown shaded, because it does not represent a region with a lower density of dislocations. At the third stage of the synthesis part 81 and 83 can be cut from the grown rectangle 79, and each grows to full effective rotation, growing from their ribs <100> education substrates 84 and 84' with a square surface, and triangular sections 85 and 87 growth represent lateral growth with triangular substrates 81 and 83, respectively. Both substrate 84 and 84', which began with the lateral growth and forming lateral growth are is a region with a lower density of dislocations, as indicated by hatching in the figure 8d. The original triangular substrate with its excessive epigastric growth 77' can then be used to create two triangular sections 89 and 90 of growth (figure 8c). They are again shown shaded, as they represent the areas with lower density of dislocations. You can cut parts 89 and 90 and repeat the process. Embodiment shown in figure 8, demonstrates how to provide a theoretically infinite source having a low dislocation density records from grown by CVD diamond material of intermediate size, ranging from one substrate 71.

It should be noted that, if there are two parties that have the orientation <100>, as in the example shown with reference to figure 8, the production time required to transition to the next stage, is reduced compared with the case where there is only one party, with the orientation <100> (as in case of the implementation in figure 7). This is because of the fact that good growth is achieved on two faces at the same time.

You could use any combination of the above options for implementation. Specialists in the art would have been obvious how these various examples could be combined, resulting in the variety of the products, and how some of the resulting products could be particularly advantageous, for example, especially with increased individual area, or especially a larger total area of multiple substrates intermediate or small area, and almost dislocation of the substrate.

The embodiments presented above with reference to the drawings, generally described as the substrate with straight edges separating two different directions <100>. In practice, the invention is applicable to substrates, in which two perpendicular directions <100> can be separated component of the second or more directions. This is, for example, a small section of the <110>. Experts in the art would recognize that many of these ideas also apply to plates with a preferential orientation <110> ribs, although the exact numerical increase the lateral area, as defined with reference to several implementation options that would be slightly modified in such geometric configurations that can calculate a specialist in this field of technology.

Shown in the embodiments of figures it is assumed that the growth rate in the direction <100> plane of the sheet are the same as the rate of growth in the [001]direction, perpendicular to the plane of the sheet. In practice, this may not the origin Taiwan is employed. For example, it was found that it is possible to grow crystals, in which the rate of lateral growth in the direction <100> exceeds the rate of vertical growth in the [001]direction. These factors affect the production time, which is each of the individual stages of the synthesis presented in illustrated examples. If in the drawings, the thickness (for example, a/2), which need to grow to the next stage of the synthesis, is indicated above the arrow, it means the transition from one stage to the next, and this thickness implies conditions, when the speed side in the direction <100> and the vertical in the direction of the {001} growth are the same.

In addition, in the illustrated implementations, it is assumed that the rotary growth continues only until the corners of the original substrate. In practice, this growth can continue beyond the original corners of the sheet, if provided with good conditions, although such subsequent growth can be slowed down by the formation of twins {111}.

In order to achieve the described space, it is desirable preferred process parameters, e.g. temperature, pressure, gas, power, chemical process (the amount of methane, nitrogen, hydrogen, oxygen, argon and other gases), etc. as discussed above with reference to the parameter α. However, for certain applications, Nai is more preferred process parameters to achieve the preferred area increase may not be preferred for other desirable properties of the grown crystal.

Hereinafter the invention will be described in more detail by the following non-restrictive examples.

EXAMPLES

Example 1 a Rectangular substrate with all edges <100>

Chose synthetic HPHT diamond plate type 1b with a pair of approximately parallel main faces within ~5° from the (001). From plates made of a rectangular substrate that is suitable for homoepitaxial synthesis of single-crystal diamond material by a CVD method using a process comprising the following steps:

i) splitting the laser substrate to obtain a plate with all edges <100>;

(ii) grinding and polishing the main surface on which to expand, and sanded and polished the piece had a size of approximately 5.0 mm × 7.6 mm 400 μm in thickness with all faces {100}. The surface roughness Raat this stage amounted to less than 10 nm in the measured area, comprising at least 50×50 μm. The value of Ra(sometimes referred to as "RA" or "average from the Central line" or "c.l.a.") is the arithmetic mean of the absolute deviation of surface profile from the mean line measured supovym profilometer measured on the length of 0.08 mm, measured according to British standard BS 1134, part 1 and part 2. Here is the mathematical description of Ra(skygi "Tribology" ("Tribology"), I. M. Hutchings, publisher Edward Arnold, London, 1992, pages 8-9):

(i.e. the arithmetic average of the absolute deviations of the surface profile measured supovym profilometer, usually on the length of 0.08 mm). Dimension Rausing supalogo Profiler is well known in the technique, and there are numerous devices that are suitable for such measurements; for example, the inventors used the device "Taylor Hobson FormTalysurf 50" (Taylor Hobson Ltd, Leicester, UK).

The substrate was mounted on a tungsten polictial using high temperature brazing of diamond materials, providing a first substrate according to the method of the first aspect of the invention, as illustrated in figure 1. The substrate and its holder was then placed in a chamber of the CVD reactor and started the cycle of etching and growth, feeding into the chamber gases as follows.

First was carried out by etching in place of an oxygen plasma at a pressure of 30260 PA (230 Torr) and the temperature of the substrate 787°C, then held etching with hydrogen, and at this stage, the oxygen is displaced by the gas flow. Then began the process of growth by the introduction of methane consumption 22 STS3/min (standard cubic centimeters per second) and alloying gases. In the working gas was also attended by nitrogen and hydrogen. The temperature of the substrate at this hundred the AI amounted to 827°C. Through the next 24 hours, the methane concentration was increased to 30 STS3/min. Such growth conditions were chosen to obtain the value of the parameter α in the range of 2.0±0.2, which was measured during the subsequent crystallographic study.

The study grown by CVD diamond plates revealed an almost complete rotation of the plate, which did not include doubles and cracks on the face (001). Dimensions after synthesis does not contain doubles top face (001) was 9.4 mm × 9.4 mm, and the thickness is grown by the CVD method layer of diamond material was 2.3 mm This process gave at 1,06 times more plaque than expected 8.9 mm × 8.9 mm, which would be achieved with full effective rotation, as described, for example, with reference to the embodiment represented in figure 2d, according to the formula of 0.5(a+b)2. Percentage increase in area compared with the original substrate was 132%, in contrast to the predicted 100%, and therefore, this corresponds to growth for the full effective rotation thereby, as described above with reference to figure 2e. In addition, the upper surface (001) of the sample did not contain twins and other defects directly to her ribs.

Example 2 - a Rectangular substrate with ribs <110>

The substrate was chosen synthetic HPHT diamond plate type 1b, following the same to the iterim choice as for the plate in example 1. This plate cut by laser, receiving a record containing four small side faces {110} and the two main faces {001}, restricted to edges <110>. The plate was then polished and polished in the same manner as the plate in example 1. Using this method, the prepared substrate with dimensions 6.38mm × 5,65 mm 0,60 mm thick.

The substrate was mounted on the holder using one of the main faces {001}. This plate was introduced into the reactor, where he started the cycle of etching and growth, as described below:

First was carried out by etching in place of an oxygen plasma at a pressure of 21 kPa, after which the spent etching by hydrogen with simultaneous removal of O2from the gas stream. Then began the process of growth by the introduction of methane together with alloying gases. Methane was injected with a flow rate of 40 STS3/min In the working gas was also attended by nitrogen and hydrogen. Through the next 24 hours, the methane concentration was increased to 165 SSM3/min. these growth conditions were chosen to obtain the value of the parameter α in the range of 2.0 ą 0.2. Growth under these conditions was continued for more than 100 hours.

After completion of the growth period, the substrate was removed from the reactor and removed from the substrate grown by CVD diamond plate.

The study grown by CVD diamond layer revealed that the plate is not who won the doubles and cracks on the verge of growth (001). Dimensions after synthesis does not contain doubles top face (001) was 8.0 mm × 6.4 mm, and the thickness is grown by the CVD method layer of diamond material was 3.1 mm, This process gave the plate with the percentage increase in area compared with the original substrate 42%, while the projected increase in area compared with the original area was 0% (substrate (001) with the side faces {110} is not undergoing a "rotation", and therefore it was impossible to foresee the increase in the area). It is believed that the reason for the higher than expected increase in area is that growth occurred in the conditions close to α=2. Indeed, the subsequent calculation of the parameter α from measurements of the grown crystal have shown that the value of the parameter α was 2.3. In addition, the upper surface of the (001) sample unexpectedly did not contain twins and other defects right up to its edge; as a rule, regional (110) face is prone to twinning, which limits growth in the vertical direction, because the twins come on the top surface growth. Consider that near α=2 growth conditions allowed the preservation of the delicate balance between preventing instabilities growth on the surface of the growth of (001) and the formation of twins on the lateral faces {110}, as discussed above.

Example 3 - a Rectangular substrate with a big soo the wearing of the parties

Three synthetic HPHT diamond plate type 1b was selected and prepared to the synthesis, using the same selection criteria as in the previous examples. Each of the three plates used in this example had an aspect ratio of more than 3, namely:

Plate 1 had dimensions of 4.16 mm × 0,88 mm (aspect ratio 4,73) and a thickness of 0.51 mm

Plate 2 had dimensions to 3.89 mm × 0.64 mm (aspect ratio between 6.08) and a thickness of 0.51 mm

Plate 3 was the size of 3,66 mm × 0,97 mm (aspect ratio of 3.77) and the thickness of 0.61 mm

These plates are laser cut, sanded and polished, receiving the substrate with all the side faces {100} major faces {001}, then cut, ground and polished substrates were mounted on a suitable holder and were growing during a number of different experiments on the synthesis. Conditions were as similar as possible. The reactor was carried out by the etching cycle and growth. The etching conditions were the same as in example 1. The growth conditions were the same as in example 1, except that the introduction of methane has increased from 22 STS3/min to 34 STS3/min through approximately 70 hours. These growth conditions were chosen to obtain the value of the parameter α in the interval 2,0±0,2.

After growth the study of three grown by CVD diamond layers revealed the complete rotation of the plates, which are not sod the whinnying of doubles and cracks on the verge of growth (001). Dimensions after synthesis does not contain doubles top face (001) of the three plates were as follows:

Plate 1 - 6.0 mm × 6.0 mm and grown by CVD diamond layer thickness 3,19 mm

Plate 2 - 5.6 mm × 5.6 mm and grown by CVD diamond layer thickness of 3.13 mm

Plate 3 - 5.6 mm × 5.6 mm and grown by CVD diamond layer thickness is 3.08 mm

This process gave the album with a much larger size than the forecast of 3.56 mm × 3,56 mm 3,20 mm × 3,20 mm 3.27 mm × of 3.27 mm for plates 1, 2 and 3, respectively, which would be achieved with the full rotation of the source substrate according to the formula [(a+b)/√2]. Percentage increase in area compared with the area of the original substrate for each of the plates was as follows:

Plate 1 - 453% (predicted 250%).

Plate 2 - 642% (predicted 191%).

Plate 3 - 350% (predicted 201%).

Grown diamond material was measured and calculated values of the parameter alpha, which amounted to 2.3 and 2.2 and 2.3 for plates 1, 2 and 3, respectively. In addition, the upper surface (001) of all three samples did not contain twins and other defects right up to their edges.

Record 1 of this example was processed, having a synthetic gemstone with round brilliant cut weight of 0.42 carats.

The present invention additionally provides for any Nova is a sign or any combination of signs, described above, which, as understood by a qualified reader, you could choose in conjunction.

1. A method of growing single crystal diamond material, including:
(a) providing a first diamond substrate, which has a main surface (001), and this main surface is limited to at least one edge of <100>length mentioned at least one edge <100> greater than the longest dimension of the surface, which is orthogonal mentioned at least one edge <100>in a ratio of at least 1.3:1; and
(b) growing single-crystal diamond material homoepitaxial on the main surface (001) of the first diamond substrate under the conditions of synthesis by chemical vapor deposition from the vapor or gas phase (CVD), and single-crystal diamond material grows as normal to the main surface of the (001)and aside from it,
at the same time during the CVD process, the value of α is in the range from 1.4 to 2.6, where α=(√3×growth rate in the <001>) ÷ the growth rate in the <111>.

2. The method according to claim 1, the method includes growing a single crystal diamond material homoepitaxial on the main surface (001) of the first diamond substrate, and the growth continues until the full effective rotation of said main surface (001) first is th diamond substrate,
this full effective rotation of said main surface (001) of the first diamond substrate is achieved when the side of said main surface is (001), limited to the first diamond substrate mentioned at least one edge of <100>is limited in the grown single crystal diamond material of the two orthogonal edges <110>, which intersect each other and which cover and replace the whole line, the source specific mentioned at least one edge of <100>.

3. The method according to claim 1, the first diamond substrate has a main surface (001), which is almost rectangular.

4. The method according to claim 3, when the rectangular substrate is limited by the ribs <100>.

5. The method according to claim 3, including the initial stage of providing a diamond substrate precursor having a main surface (001), and cut an inscribed rectangular diamond substrate from the diamond substrate predecessor, and inscribed rectangular substrate cut out having ribs <100>and carved inscribed rectangular substrate provides mentioned the first diamond substrate.

6. The method according to claim 5, with rectangular cut diamond substrate is cut to maximize the value of a+b, where a and b represent, respectively, long and short hand carved pramool the Oh diamond substrate.

7. The method according to claim 1, the first diamond substrate has a main surface (001), which is almost triangular.

8. The method according to claim 7, almost triangular main surface is a rectangular triangle, which is limited to one edge of <100> and two ribs <110>or two edges <100> and one edge of <110>.

9. The method according to any preceding paragraph, including (a) the cut of the diamond material from the area of the lateral growth of the grown single crystal diamond material so that the cut of the diamond material provides a surface (001) with edge <100>, and (b) growing single-crystal diamond material homoepitaxial on this surface (001) - cut diamond material.

10. The method according to claim 9, with carved diamond material lateral growth provides almost rectangular or triangular surface (001).

11. The method according to claim 3, including the location of two or more rectangular substrates, each of which has a main surface (001) and at least one rib <100>, next to each other so as to provide a continuous edge <100>, which exceeds the length of the longest edge <100>any of the mentioned two or more rectangular substrates.

12. The method according to claim 1, when α is in the range from 1.8 to 2.2.

<> 13. The method according to claim 1 for the production of single-crystal diamond plates, including the stage of processing grown by the method of homoepitaxial CVD single crystal diamond material in the record.

14. Grown by CVD single crystal diamond material containing many rows of dislocations, with each row extends almost in the direction of the <001>, each row of dislocations when projected on the plane (001) defines a point, and these points when connecting define a first segment extending in the direction <100>, and the second line segment which intersects the first mentioned section and extends in the direction <100> or <110>and the ratio of the first segment to the second segment, or Vice versa, is at least 1.3:1.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: germanium monocrystals are grown in crystallographic direction [111] after holding at melting point for 1-2 hours, with temperature gradient at the crystallisation front in the range of (10.0÷18.0) K/cm, which provides dislocation density on the level of (2·104-5·105) per cm2.

EFFECT: invention enables to obtain germanium monocrystals with considerable increase in signal reception area due to directed introduction of a given concentration of dislocations into the grown crystal and conversion of said dislocations from standard crystal defects to active elements of infrared optical devices.

3 dwg, 1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to processing crystals, for example, amber, pearls and the like with Mohs hardness lower than 4. Proposed method comprises faceting at abrasive wheel with grain size of 20-40 mcm and finishing at abrasive disk with hardness exceeding that of processed material by fine free abrasive. Note here that facet is set and moved off the disc surface at disc zero rpm to prevent damaging the facet by abrasive particles accumulated in front of facet in rotation. Diamond powder, or aluminium oxide, or cerium oxide, is used as abrasive.

EFFECT: finishing to 11th finish class to GOST 2789-59.

6 cl, 2 ex

FIELD: process engineering.

SUBSTANCE: invention relates to diamond processing, in particular, by thermochemical process. Proposed method comprises applying layer of spirit glue composition onto diamond surface, said composition containing transition metal, for example, Fe, Ni or Co, and processing diamond thermally at temperature not exceeding 1000°C. To prepare spirit glue composition, powder of water-soluble salt of transition metal is used. Said powder in amount of 1-10 wt % of water solution is mixed with spirit solution of glue at salt water solution-to-glue spirit solution ratio of 1:1. Prepared mix is applied on diamond surface in 10-20 mcm-thick layer to be dried. Thermal processing of diamond is performed in two steps. Note here that, at first step, diamond is processed at 600-700°C for 1-2 min, while, at second step, it is processed at 800-1000°C for 15-30 min.

EFFECT: superhigh specific surface with nano-sized (100-200 nm) relief, expanded applications.

2 dwg, 7 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in simultaneous growth of multitude of work pieces of moissanite crystals in cellular mould of forming graphite, in dividing them to separate crystals, in faceting, grinding and in polishing. Before faceting, grinding and polishing work pieces are first glued on a mandrel, then they are re-glued on a back side. Moissanite is polished on a ceramic polisher rotating at rate from 200 to 300 rpm with utilisation of diamond powder (spray) with dimension of a grain from 0.125 to 0.45 mcm, facilitating depth of grooves less, than length of light wave of a visible part of spectre. Also, cut and chipped edges of the work piece with defects not suitable for faceting, are crumbled and returned to a stage of growth. Grinding paste with size of a grain 0.25 mcm can be used for grinding.

EFFECT: increased quality of crystals, increased efficiency due to elimination of cutting operation; reduced expenditures for production and losses of material at cutting during work piece growth.

2 cl, 3 ex

FIELD: electricity.

SUBSTANCE: semiconductor crystal of silicone carbide includes monocrystal seed part 21 and monocrystal grown part 22 on the above seed part 21; at that, seed 21 and grown 22 parts essentially form regular cylindrical monocrystal of silicone carbide 20; at that, boundary between grown and seed part shall be determined by seed part 23 which essentially is parallel to bases of the above regular cylindrical monocrystal 20 and has deviation from axis approximately through 0.5°-12° relative to base plane 26 of monocrystal 20, and the above monocrystal grown part reproduces polytype of the above monocrystal seed part and has the diametre at least of 100 mm.

EFFECT: obtaining high-quality monocrystals of silicone carbide of big diametre, from which separate plates with off-axis surfaces in the form of circle can be obtained.

28 cl, 7 dwg

Items out of spinel // 2336372

FIELD: metallurgy.

SUBSTANCE: invention refers to process of fabricating items with spinel crystal structure, such as plates, paddings and active facilities comprising them. According to one version a monocrystal spinel plate is fabricated by treatment of melt and has a non-stoichometric composition defined with a common formula aAD.bE2O3, in which A is chosen out of group including Mg, Ca, Zn, Mn, Ba, Sr, Cd, Fe and their combinations as well, E is chosen out of group including Al, In, Cr, Sc, Lu, Fe and their combinations, while D is chosen out of group O, S, Se, and their combinations as well; at that ratio b:a>2.5:1, so that spinel is enriched with E2D3. Besides a monocrystal spinel material is opened possessing a non-stoichometric composition having a window within the range of waves from 400 to 800 nm. Such items possess reduced mechanical tensions, which facilitates increased output of accepted items.

EFFECT: facilitating increased output of spinel items.

32 cl, 5 tbl, 13 dwg

FIELD: technological processes; chemistry.

SUBSTANCE: single-crystal spinel plate has front and back sides, <111> crystallographic orientation and external perimeter, which has the first and the second facets, at that the first facet means direction of plate cleavage plane, which passes through front surface of geometric locus of points that stretches along the line, which is parallel to the first facet, and the second facet means direction of cleavage plane breaking, at that plate is made of composition in accordance with common formula aAD•bE2D3, in which A is selected from group that includes Mg, Ca, Zn, Mn, Ba, Sr, Cd, Fe, and also their combinations, E is selected from group, which includes Al, In, Cr, Sc, Lu, Fe, and also their combinations, and D is selected from group, which includes O, S, Se, and also their combinations. Boule and plates prepared from it mainly consist of single spinel phase, without secondary phases, and do not contain contaminants and alloying admixtures, i.e. possess improved technological characteristics.

EFFECT: higher extent of finished products output; increase of plates size and reduction of processing cost in manufacture of semiconductors.

18 cl, 1 tbl, 1 ex, 5 dwg

FIELD: technological process.

SUBSTANCE: invention pertains to the technology of obtaining plates made from monocrystalline diamond, grown using a chemical vapour deposition method (CVDM) on a substrate. The grown diamond is divided across the surface of the substrate and the plate is obtained. Its main surfaces are located across the surface of the substrate.

EFFECT: obtaining plates with large area, which do not have natural defects.

41 cl, 4 ex, 6 dwg

FIELD: treatment of silicon mono-crystals grown by Czochralski method, possibly manufacture of mono-crystalline silicon chips- members of solar batteries and integrated circuits.

SUBSTANCE: method comprises steps of pseudo-squaring of silicon mono-crystal for further grinding ribs of pseudo-squared ingot; cutting mono-crystals by chips. Ribs are ground alternatively; each rib is ground layer by layer in motion direction of tool and in parallel relative to lengthwise axis of ingot.

EFFECT: improved quality of mono-crystalline silicon chips due to safety of near-contour region of worked zone of ingot, lowered material (silicon) losses at working ingots.

3 cl, 1 ex, 1 tbl, 3 dwg

FIELD: chemical industry; other industries; methods of machining of the piezoelectric substrates.

SUBSTANCE: the invention is pertaining to the machining of the piezoelectric substrates, in particular, it is dealt with the precision machining of the slices of the lanthanum-gallium silicate of the orientation (0, 138.5, 26.7) by the method of the lanthanum-gallium silicate lapping and polishing. The invention may be used at manufacture of the piezoelectric devices using the surface acoustic waves. The method provides for the double-side a double-side lapping with usage of the aqueous suspension of the micropowder of the green silicon carbide at the specific pressure on the substrate of 20-60 g/cm2 and the chemical-mechanical polishing of the substrates preliminary pasted in-pairs by their non-working sides with the help of the solution containing (in mass %): suspension of silicon dioxide - 8-11.5, orthophosphoric acid - 0.8-1.5, the distilled water - 87-91.2 at the specific pressure on the substrate of 50-90 g/cm2. The method allows to improve the frequency characteristics of the devices operating in the range of the surface acoustic waves ensuring production of the plain parallel substrates at the speed of removal of the substrate material within the range of 5-10 microns/hour at achievement of the roughness of the lapped surface the value of Ra ≤ 0.7 nanometers.

EFFECT: the invention ensures the improved frequency characteristics of the devices operating in the surface acoustic waves range, provision of production of the plain parallel substrates at the speed of removal of the substrate material within the range of 5-10 microns/hour at achievement of the roughness of the lapped surface below 1 nanometer.

5 cl, 1 ex

FIELD: metallurgy.

SUBSTANCE: diamond-like coatings are produced in vacuum by spraying of target material with an impulse laser. The target material made of graphite of high degree of purity (more than 99.9%) is exposed to combined laser radiation: first short-wave (less than 300 nm) pulse radiation, the source of which is a KrF-laser with wavelength of 248 nm and specific energy of 5·107 W/cm2, as a result of which ablation is carried out, and gas-plasma phase of target material is generated. Subsequent exposure of a gas-plasma cloud during cloud flight from a target to a substrate is carried out by long-wave (more than 1 mcm) laser radiation. The source of long-wave laser radiation is a gas CO2-laser or a solid-state fibrous laser radiator.

EFFECT: increased diamond phase in a produced coating and increased energy spectrum of plasma at stage of its flight.

3 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to technology of production of synthetic diamond material, which can be applied in electronic devices. Diamond material contains single substituting nitrogen (Ns0) in concentration more than 0.5 ppm and having such complete integral absorption in visible area from 350 nm to 750 nm, that at least nearly 35% of absorption is attributed to Ns0. Diamond material is obtained by chemical deposition from vapour or gas phase (CVD) on substrate in synthesis medium, which contains nitrogen in atomic concentration from nearly 0.4 ppm to nearly 50 ppm, and gas-source contains: atomic part of hydrogen, Hf from nearly 0.40 to nearly 0.75, atom part of carbon, Cf, from nearly 0.15 to nearly 0.30; atomic part of oxygen, Of, from nearly -.13 to nearly 0.40; and Hf+Cf+Of=1; ratio of atomic part of carbon to atomic part of oxygen, Cf:Of, satisfy the ratio nearly 0.45:1<Cf:Of< nearly 1.25:1; and gas-source contains atoms of hydrogen, added in form of hydrogen molecules, H2, with atomic part of the total quantity of present atoms of hydrogen, oxygen and carbon between 0.05 and 0.40; and atomic parts of Hf, Cf and Of represent parts from the total quantity of atoms of hydrogen, oxygen and carbon, present in gas-source.

EFFECT: invention makes it possible to obtain diamond material with rather high content of nitrogen, which is evenly distributed, and which is free of other defects, which provides its electronic properties.

17 cl, 11 dwg, 6 ex

FIELD: metallurgy.

SUBSTANCE: monocrystalline diamond material that has been grown using a CVD method and has concentration of single substituent nitrogen [Ns0] of less than 5 ppm is irradiated to introduce isolated vacancies V to at least some part of the provided CVD-diamond material so that total concentration of isolated vacancies [VT] in the obtained diamond material is at least more than (a) 0.5 ppm and (b) by 50% more than concentration [Ns0] in ppm in the provided diamond material; after that, annealing of the obtained diamond material is performed so that chains of vacancies can be formed from at least some of the introduced isolated vacancies at the temperature of at least 700°C and maximum 900°C during the period of at least 2 hours; with that, irradiation and annealing stages reduce the concentration of isolated vacancies in diamond material, due to which concentration of isolated vacancies in the irradiated and annealed diamond material is <0.3 ppm.

EFFECT: diamonds obtain fancifully orange colour during such treatment.

16 cl, 3 dwg, 4 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to diamond grinding in making diamond rock cutting tool. Proposed method comprises processing the diamonds in velocity layer of magnetic fields together with ferromagnetic particles. Mix composed of ferromagnetic particles and diamond grains fills the cylindrical case by 0.25-0.35 of its volume. Diamond magnetic susceptibility is defined by the relationship: X1gR1(R1+R2)224μ0ρ2R22H2X2, where X1, X2 are diamond and ferromagnetic particle magnetic susceptibility, m3/kg; g is acceleration of gravity, m/s2; R1, R2 are diamond and ferromagnetic particle grain radii, m; µ0 is magnetic permeability of vacuum, (µ0=4π·107 GN/m); ρ2 is ferromagnetic particle density, kg/m3; H is magnetic field intensity, A/m. Note here that the relationship between diamond grain weight and that of ferromagnetic particles makes 0.51-0.61.

EFFECT: higher efficiency of grinding and quality of finished diamonds.

1 cl, 2 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method of making monocrystalline and polycrystalline diamond plates with a large surface area involves arranging, without touching each other, workpiece monocrystals with surface orientation (100) on a substrate holder, creating nucleation centres on the surface of the substrate holder free from the workpiece monocrystals, simultaneous chemical vapour deposition (CVD) of an epitaxial layer on the surface of workpiece monocrystals and a polycrystalline diamond film on the remaining surface of the substrate holder. As a result of chemical vapour deposition of the diamond, splicing of monocrystalline and polycrystalline diamond takes place on the side surface of the workpiece monocrystals to form a diamond plate of a large surface area, having spliced monocrystalline and polycrystalline diamonds. To obtain a plane-parallel CVD diamond plate, the grown composite diamond substrate is polished on both sides.

EFFECT: obtaining plates of monocrystalline and polycrystalline CVD diamond of a large surface area, having a common smooth outer surface.

5 cl, 7 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to production of synthetic polycrystalline materials based on polycrystalline cubic boron containing diamond grains. Said materials are used for making cutting elements to be incorporated with drill bits, grinding wheel dressing, drilling and cutting of natural and artificial construction materials. Proposed method comprises subjecting the blend containing cubic boron nitride and diamond powder to pressure in the range of thermal stability of aforesaid components at state graphs. Note here that grain sixe of diamond powder used in amount of 5.0-37.5 vol. % makes 200-3000 mcm while that of hexagonal boron nitride makes 1-3 mcm and that of cubic boron nitride makes 1-5 mcm.

EFFECT: higher efficiency in drilling rocks of V-XII rock drillability index.

3 cl

FIELD: chemistry.

SUBSTANCE: method involves decomposition of solid carbonyl compounds of platinum metals in a gaseous medium at high temperature in a sealed container to form diamonds and doping said diamonds with boron at temperature of 150°C-500°C for 2-5 hours in a gaseous medium which contains carbon monoxide CO and diborane B2H6 with weight ratio of boron to carbon in the gaseous mixture of 1:100-1000.

EFFECT: obtaining high quality diamond monocrystals with semiconductor properties.

1 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemical and jewellery industry. Diamonds are synthesised in a high-frequency induction crucible furnace with frequency range of 60-100 kHz. A ceramic crucible 1 is fitted with a ceramic grid 2 with holes with diameter of 0.3-0.5 mm, lying at a height of 20 mm from its bottom, and a ceramic pipe 3 with inner diameter of 15-20 mm for feeding a mixture of methane and carbon dioxide with specific volume rate of 60-70 h-1. Sodium carbonate and potassium carbonate are fed into the crucible 1, said carbonates being mixed in equimolecular ratio and heat treated at 400-450°C for 2 hours. Diamond synthesis is carried out in one day at temperature of 700-900°C in a melt of said salts in the presence of a catalyst - powdered iron with granule size of 3-5 mm in amount of 5-10% of the molten mass. Gas supply is cut at the end of the process. The molten salts, along with the catalyst and diamonds, are poured into moulds. The cooled down ingots are fed into a reactor - crystalliser 5. After dissolving the sodium carbonate and potassium carbonate, the suspension of catalyst and diamonds is fed onto a filter 6.The obtained filtrate is used in the reactor-crystalliser 5, and the diamond crystals are separated from the catalyst by a magnet.

EFFECT: invention simplifies the process, increases efficiency of the process and excludes toxic and explosive substances.

FIELD: process engineering.

SUBSTANCE: invention relates to production of diamonds and diamond polycrystalls. Proposed method comprises subjecting blend bearing carbon material and catalyst to pressure and temperature in the region of diamond thermodynamic stability. Catalyst represents a mix of metallic component with phosphorus, or the mix of alloys. Metallic component is selected from the group: iron, manganese, silicon. Metallic component-to-phosphorus ratio is selected so that to allow synthesis at temperature not exceeding 1450°C. Additionally, alloying metal may be added to said blend selected from the group: B, Si, Ti, Zr, Cr, Ni, Mo, Vo, or their mix, or alloy.

EFFECT: higher-strength and fraction resistance diamonds.

7 cl, 1 tbl, 4 ex

FIELD: process engineering.

SUBSTANCE: invention may be used in solid-state engineering in making n-type conductivity materials. Reaction system of graphite and phosphorus is sintered in hydrogen flow at 200-280°c. Then diamond is synthesized at 1450-1650°C and 6.3-7.5 GPa limited at 6.3 GPa by the range of 1550-1650°C and, at 7.5 GPa, by the range of 1450-1550°C for, at least, 40 hours. In compliance with second version, diamond is drown at seed faces {11} and {100} at 1400-1600°C and 6.3-7.5 GPa limited at 6.3 GPa by the range of 1500-1600°C and, at 7.5 GPa, by the range of 1400-1500°C at, at least, 40-60 hours.

EFFECT: efficient doping, higher quality of diamond, decreased temperature and pressure.

2 cl, 2 dwg, 1 tbl, 6 ex

FIELD: carbon materials.

SUBSTANCE: invention relates to preparation of boron-alloyed monocrystalline diamond layers via gas phase chemical precipitation, which can be used in electronics and as jewelry stone. The subject matter is uniformity of summary boron concentration in above-mentioned layer. The latter is formed in one growth sector and characterized by thickness above 100 μm and/or volume exceeding 1 mm3. Boron-alloyed monocrystalline diamond preparation involves diamond substrate provision step, said substrate having surface containing substantially no crystal lattice defects, initial boron source-containing gas preparation step, initial gas decomposition step, and the step comprising homoepitaxial growth of diamond on indicated surface containing substantially no crystal lattice defects.

EFFECT: enabled preparation of thick high-purity monocrystalline diamond layers exhibiting uniform and useful electronic properties.

44 cl, 5 tbl, 7 ex

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