Controlled formation of dislocations in monocrystalline synthetic diamond material

FIELD: chemistry.

SUBSTANCE: invention relates to production of monocrystalline diamond material by chemical vapour deposition (CVD), which is used in optical, mechanical, fluorescent and/or electronic devices. A diamond layer contains a mesh of nonparallel intercrossing dislocations as seen on an X-ray topographic sectional image or in conditions of a fluorescent technique, wherein the layer has thickness equal to or greater than 1 mcm; the mesh of nonparallel dislocations stretches across a volume which is at least 30% of the total volume of the diamond layer, and wherein the mesh of nonparallel dislocations contains a first set of dislocations propagating in a first direction through the diamond layer, and a second set of dislocations propagating in a second direction through the diamond layer, wherein the angle between the first and second directions is in the range of 40° to 100°, as seen on an X-ray topographic sectional image or in conditions of a fluorescent technique.

EFFECT: invention enables to control the type and/or direction of dislocations in a diamond material without affecting optical and/or electronic properties of devices based on said material and optimise said properties for a specific application.

12 cl, 8 dwg, 2 tbl, 3 ex

 

The technical field TO WHICH the INVENTION RELATES

The present invention relates to a method for producing single crystal diamond material using the method of chemical deposition from the gas phase (CVD). Some variants of implementation relate to the method that allows you to control the number, distribution, direction, and/or the type of dislocations within a single crystal CVD diamond material. Some variants of implementation also apply to single crystal diamond material that can be manufactured in accordance with the ways described here. Some variants of implementation of the present invention also relates to the use of these materials in optical, mechanical, luminescent and/or electronic devices.

The LEVEL of TECHNOLOGY

Dislocation often have very harmful effects on the physical and optoelectronic properties of products made from crystalline diamond. For example, the hardness and/or wear resistance may depend on the density and direction of dislocations. In addition, dislocations can affect the optical and electronic devices based on the use of crystalline diamond material.

Diamond is renowned as a material with exceptional hardness and excellent mechanical properties, and this leads to er� use in various applications (e.g., for mechanical drilling). It is known that dislocations affect these properties and, in particular, in homoepitaxial CVD synthetic diamond material dislocations generally propagate in a direction approximately parallel to the growth direction of the material. The resulting grid of parallel dislocations usually affects the mechanical properties of the material.

Parallel significant dislocation density, which propagate in the direction of the <001> synthetic diamond crystal grown homoepitaxially on the substrate (001), lead to considerable stress and therefore to a significant birefringence in the amount of synthetic diamond material that has been shown to reduce its operating parameters for some optical applications such as Raman lasers (see, for example, "Raman laser with internal three-dimensional cavity using synthetic single crystal diamond", Walter Lubeigt and others, " Optics Express, Vol. 18, No. 16, 2010). In this case, it would be desirable to reduce the total voltage or, at least, to achieve a better distribution of the stresses in the material to ensure the best optical performance. A large birefringence is observed when the apparent optical axis coincides with the linear direction parallel to dislocate�, that is, when it is parallel to the direction of growth. In optical applications based on simple technological reasons (e.g., to maximize the area) it is convenient to treat the main facets of the material that is perpendicular to the direction of growth. This leads to the formation of dislocations perpendicular to the main faces of the material and visible parallel to the axis that leads to the large birefringence.

It is also believed that different types of dislocations and different directions of dislocations in different ways to affect the operation of devices with CVD synthetic diamonds. It is established that the ability to choose certain linear direction of dislocations and not any other can influence the optical and/or electronic properties of devices based on diamond and optimize them for a particular desired application.

In light of the above solved one of the challenges is to mitigate the harmful effects of some types of dislocations and/or directions of dislocations in single crystal CVD synthetic diamond material, particularly in connection with optical, mechanical, luminescent and electrical applications.

The above problem has been at least partially addressed through the development of methods that reduce the number of dislocations for a�the organization of their harmful effects. For example, documents WO2004/027123 and WO2007/066215 disclose methods of forming the CVD synthetic diamond material with small concentrations of dislocations so as to provide the diamond material of high quality, suitable for optical, electronic, and/or detector devices. However, the formation of CVD synthetic diamond material with a low dislocation density can be relatively difficult, time consuming and expensive.

Despite other sources of dislocations two prevailing source of dislocations include: (i) threading dislocations extending from the substrate to the CVD layer; and (ii) dislocations formed at the interface between the substrate and the CVD layer. In respect of (i) the vertical section of the primary CVD layer to detect faces (001) and the cultivation of a secondary layer on this face leads to dislocations, sprouting from the primary to the secondary layer (this preserves the burgers vector). Given that the dislocation in the primary layer have a direction <001> and represent a boundary or 45°-s mixed-type dislocations, there are many permutations of threading dislocations within secondary CVD layer (see Table 1). However, all of the threading dislocations are located in the direction <100> and are either boundary or 45°-mi of the mixed type. Accordingly, while this work de�will onstreet to some extent controlled formation of dislocations, it is limited in relation to the linear direction of dislocations, and on the type of dislocations. In connection with (ii), previous studies (see, e.g., M. P. Gaukroger, etc., Diamond and related materials (Diamond and Related Materials 17 262-269 (2008)) showed that the preparation of the substrate is of importance in determining the type of dislocations in CVD layers grown on standard substrates (001). Dislocations propagating from surface defects (such as from rough polished substrate) are typically 45°s dislocation of the mixed type is the most sustainable type of dislocations in (001) growth.

Table 1
[001] growth on (001)-Rostov vertically cut primary CVD layer, showing the different type of dislocation, if threading dislocation secondary layer are in a linear direction [010]
Primary layerLinear direction tionThe burgers vectorThe type of dislocationSecondary layerLinear direction tionThe type of dislocation
(001)[001][101]Smash�Naya 45°-th (100)[010]Mixed 45°-th
(001)[001][011]Mixed 45°-th(100)[010]Regional
(001)[001][110]Regional(100)[010]Mixed 45°-th
(001)[001][1-10]Regional(100)[010]Mixed 45°-th

In light of the above it should be noted that there is a need to find ways to minimise the impact of dislocation on certain properties, such as electronic and optical properties, which may or may not be compatible with the complete reduction of the dislocation density. For example, in some applications (for example, where the required mechanical strength) high dislocation density may actually be preferred, but the direction and/or type of dislocations can be critically�and functional parameters of the material. Therefore, there is a need to find ways of controlling the type and/or direction of dislocations in homoepitaxial grown single crystal CVD synthetic diamond.

The goal of some variants of implementation of the present invention is at least a partial solution to the challenges noted above.

Disclosure of the INVENTION

In accordance with the first aspect of the present invention is single crystal CVD synthetic diamond layer containing a non-parallel grid of dislocations, and the mesh is non-parallel dislocations contains many dislocations, forming a grid of intersecting dislocations as seen on x-ray topographic image of the cross section or under fluorescent methods.

For some applications, preferably, the layer of single crystal CVD synthetic diamond had a thickness equal to or greater than 1 μm, 10 μm, 50 μm, 100 μm, 500 μm, 1 mm, 2 mm or 3 mm. Alternative or additionally, the layer of single crystal CVD synthetic diamond may have a dislocation density in the range from 10 cm-2to 1×108cm-2from 1×102cm-2to 1×108cm-2or from 1×104cm-2to 1×107cm-2and/or the value of the birefringence equal to or less than 5×10-4, 5×10-5, 1�10 5, 5×10-6or 1×10-6. Although implementations of the invention can be provided by growing the number of possible, not oriented in the direction of {100} single-crystal diamond substrates, such as oriented along {110}, {113} and {111} substrates, for some applications preferably oriented in {110} or {113} substrates. One or more of these signs are preferred to achieve a relatively thick and/or high-quality layer of single crystal CVD synthetic diamond. For example, growing on oriented along {111} substrate with a high concentration of dislocations formed in the layer of single crystal CVD synthetic diamond, can result in poor, highly stressed material, which cannot be easily grown to a large thickness without cracking.

Preferably, the mesh is non-parallel dislocation extends along a significant volume of the single crystal CVD synthetic diamond layer, and a significant amount is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total volume of single-crystal CVD synthetic diamond layer. The mesh is non-parallel dislocations may contain the first set of dislocations propagating in the first direction through the single crystal CVD synthetic�second diamond layer, and a second set of dislocations propagating in a second direction through the single crystal CVD synthetic diamond layer, and the angle between the first and second directions is in the range from 40° to 100°, from 50° to 100°, or 60° to 90°, as can be seen on x-ray topographic image of the cross section or in the conditions of fluorescent techniques. Since the dislocation is not known to propagate along a perfect straight line, the direction in which extends dislocation, can be measured as the average direction along a significant length of dislocation, where a significant length is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total length of the dislocation, and/or at least 50 μm, 100 μm, 250 μm, 500 μm, 1000 μm, 1500 μm, or 2000 μm.

In accordance with some embodiments of implementation not all dislocations in the material distributed by the above-mentioned manner. However, in some embodiments, the implementation of at least, 30%, 40%, 50%, 70%, 80% or 90% of the total number of visible dislocations within a significant amount of single-crystal CVD synthetic diamond layer to form a grid of non-parallel dislocations as seen on x-ray topographic image of the cross section or in the conditions of fluorescent techniques, and a significant amount is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of full�th volume of the single crystal CVD synthetic diamond layer.

In some embodiments, implement, for example in oriented along {110} material, mesh non-parallel dislocations may be visible on x-ray topographic image of the cross section, but not in the conditions of fluorescent techniques. In some alternative embodiments, the implementation, e.g. based on {113} the material, the mesh is non-parallel dislocations may be visible in conditions of fluorescent techniques, but not on x-ray topographic image of the cross section. This is so because of the dislocation in some linear directions emit blue fluorescent light, although other linear directions this is not happening.

In addition to the above, it was found that material having a mesh of non-parallel dislocations, as described here, has good wear resistance together with increased hardness (e.g., at least 100 GPA, more preferably at least 120 GPA).

In accordance with an additional aspect of the present invention is single crystal CVD synthetic diamond object containing monocrystalline diamond layer according to any one of the preceding claims, wherein the single-crystal diamond layer is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total volume of single-crystal CVD Sint�maceutical diamond object. Such an object can be used in optical, mechanical, luminescent and/or electronic device, or application. Alternatively, a single crystal CVD synthetic diamond, the object can be cut in the configuration of the jewelry.

In accordance with another aspect of the present invention provides a method of forming a single crystal CVD synthetic diamond layer, the method includes:

preparation of single-crystal diamond substrate with the face of growth, having a density of defects equal to or less than 5×103defects/mm2as it is revealed in the firing plasma etching; and

growing a layer of single crystal CVD synthetic diamond, as described earlier.

The face of the growth of single-crystal diamond substrate may have a crystallographic orientation {110} or {113} to form a layer of single crystal CVD synthetic diamond material having the orientation {110} or {113} for the reasons given above. The growth rate of the layer of single crystal CVD synthetic diamond can be made sufficiently small to form a grid of non-parallel dislocations. In this regard, it was found that at low speeds growth oriented along {110} substrate dislocations form a mesh of non-parallel dislocations, then� as if the growth rate increases, it generates a grid of parallel dislocations. For {110} orientation, growing a layer of single crystal CVD synthetic diamond on {110} faces of growth, when the value of the ratio of the growth rate of <110> to the growth rate of <001> below a certain limit, it becomes possible to form a grid of non-parallel dislocations. It is expected that similar considerations may apply to the orientation of {113}, although initial results indicate that a relatively large growth rate can also be used with oriented on {113} substrate, while still receiving the net non-parallel dislocations.

In accordance with some embodiments of implementation of the mesh is non-parallel dislocation contains a considerable number of dislocations that propagate at an acute angle of at least 20° relative to the direction of the growth layer of single crystal CVD synthetic diamond, and referred to a significant number is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total number of dislocations visible on x-ray topographic image of the cross section or in the conditions of fluorescent techniques. More preferably, the dislocations are propagated at an acute angle in the range of 20-60°, 20-50° or 30-50° relative to the direction of the growth layer of single crystal CVD synthetic diamond.

A BRIEF DESCRIPTION of HELL�JAY

For a better understanding of the present invention and showing how it may be exercised, options for the implementation of the present invention are described below only by way of example and in connection with the accompanying drawings.

Fig.1 depicts a block diagram of the sequence of operations showing how the various types and orientation of dislocations can be implemented in CVD synthetic diamond material, in particular, highlighted the way in which can be achieved grid non-parallel dislocations within the CVD synthetic diamond material;

Fig.2 - the steps of the method are included in the formation of the CVD synthetic diamond material having a mesh of non-parallel dislocation in accordance with a variant implementation of the present invention and possible alternative synthetic pathways that lead to parallel the grid of dislocations;

Fig.3 - types of dislocations, which propagate in the direction parallel to the direction of growth on (110) - growth CVD synthetic diamond layer;

Fig.4 - types of dislocations, which propagate at an acute angle relative to the direction of growth on (110) - growth CVD synthetic diamond layer;

Fig.5 - single-crystal CVD synthetic diamond layer comprising a grid of parallel dislocations;

Fig.6 - single-crystal CVD synthetic�quarter of the diamond layer, contains a grid of non-parallel dislocations;

Fig.7 is a micrograph of birefringence for CVD synthetic diamond material of Fig.6, which shows a relatively low voltage, due to the high dislocation density for this sample; and

Fig.8 - single-crystal CVD synthetic diamond layers grown on oriented along {110} and {113} substrates in x-ray topographic image of the cross section and in the conditions of fluorescent methods.

The IMPLEMENTATION of the INVENTION

In accordance with some embodiments implementing the present invention, the authors have developed a method for the production of single crystal CVD synthetic diamond mesh non-parallel dislocations, in particular of thick high-quality single-crystal CVD synthetic material. This differs from previous methods of production of CVD synthetic diamond, in parallel to the grid of dislocations is formed in the direction of the growth of synthetic CVD diamond films. It was found that a grid of parallel dislocations is the source of several problematic effects. For example, a grid of parallel significant dislocation density leads to stress and the birefringence in the bulk material, which reduces its operating parameters for optical applications such as lasers, Romanovs�wow scattering. A grid of parallel dislocations can affect the hardness and/or wear resistance of the diamond material. In addition, a grid of parallel dislocations can also affect fluorescence and electronic and optoelectronic properties of CVD synthetic diamond. For example, according to some researchers, for diamond detectors, certain types of dislocations can act as traps for the carriers, and also to lower the breakdown voltage.

Previous work was aimed at reducing the dislocation density in the volume of the CVD synthetic diamond materials. In contrast, the present invention intends to provide a non-parallel grid of dislocations, which propagate in different directions, forming a grid of intersecting dislocations. The presence of non-parallel grid of dislocations can be beneficial for some types of optical devices, because this configuration leads to lower voltages, which reduces the birefringence in the layer of CVD synthetic diamond. The presence of non-parallel grid of dislocations can also increase the hardness and/or wear resistance of CVD synthetic diamond materials. In addition, the presence of non-parallel grid of dislocations can also improve electronic options. For example, some types of dislocations can preferably be distributed in favor of �other types of dislocations, which act as traps for the carriers, and also lowers the breakdown voltage.

Some implementations of the invention can be applied to a CVD synthetic diamond materials of different chemical types, including, but without limitation, to materials, doped with nitrogen, phosphorus doped, boron doped and undoped CVD synthetic diamond materials. Some experimental techniques can be used to indicate that CVD diamond material is synthetic by nature. Examples include (but without limitation): there is evidence of emission at the wavelength of 467 nm and/or 533 nm and/or 737 nm in the photoluminescence spectrum measured using a wavelength of 325 nm, 458 nm or 514 nm continuous laser radiation at 77K, or the sign of the absorption at 3123 cm-1in the infrared absorption spectrum. Publication P. M. Martineau, and others (Gems & Gemology, 40 (1) 2 (2004)) selects the criteria to identify whether a diamond material is a CVD synthetic material, providing examples of CVD synthetic diamond materials that have been grown and/or annealed at a wide variety of conditions.

The term "layer" refers to any grown the field of CVD synthetic diamond, and also applies to individual CVD synthetic diamond material, which was original�produced by initial deposition of a layer on a substrate and, if necessary, the substrate is subsequently removed. May be provided a single crystal CVD synthetic diamond object containing the pre-described single crystal CVD synthetic diamond layer, and monocrystalline diamond layer, forming at least, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the total volume of single-crystal CVD synthetic diamond object.

Under the net non-parallel dislocation meant that is observed when using techniques that give the ability to visualize the dislocation in section view (for example, x-ray topography, electron microscopy or fluorescent imaging), within a significant amount of CVD synthetic diamond material, namely: (i) where two or more linear directions (i.e., not all having the same linear direction) so that one set of dislocations extend in the first direction through the single crystal CVD synthetic diamond layer, and a second set of dislocations extend in a second direction through the single crystal CVD synthetic diamond layer; (ii) dislocation of the first and second set are represented intersecting with each other; (iii) the angle between the first and second directions is in the range from 40° to 100°, from 50° to 100°, or from 60° �about 90° in a section view. A significant amount of CVD synthetic diamond material preferably is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total volume of the CVD synthetic diamond material. Within a significant amount of preferably at least 30%, more preferably at least 50%, even more preferably at least 70% and most preferably at least 90% of dislocations in the layer of CVD synthetic diamond are distributed in such a manner as described above.

It may be useful to characterize the non-parallel dislocation by comparing their linear directions with the direction of the growth of CVD synthetic diamond, which may be fixed by the research orientation of some point defects within the crystal lattice. For example, defects such as complexes of nitrogen-vacancy (NV) and nitrogen-vacancy-hydrogen (NVH) are arranged along directions <111>, giving 8 possible configurations (+ve linear direction), and the relative distribution of these configurations may exhibit a preferred orientation relative to the direction of growth. Measurements of the electron paramagnetic resonance with a variable angular orientation of the magnetic field is used to study the orientation of these defects. For example, the authors observed that with the growth on the surface (110) both ethdetect line up for the most part (equal to or greater than 50% 60%, 80%, 95% or even 99%) along two <111> orientation out of plane relative to the (110) surface growth. This preferred orientation of the defects is not observed for the same defect (e.g., NV) in the samples grown on the merits oriented in {100} substrates. If the symmetry of the correlation between the directions of <111> where these defects are, and the main planes of growth for CVD diamond, including the plane {100}, {110} and {111} is unique, then the determination of the parameters of the population distribution of defects can be used to uniquely determine the direction of growth and, in particular, whether there has been growth in the plane {110}, and the exact plane of the {110} growth in the material. Non-parallel dislocation may extend at an acute angle in the range of 20-60°, or preferably 20 to 50°, or more preferably 30-50° relative to the direction of growth (the growth direction, essentially perpendicular to the main faces {110} CVD growth, which is usually, but not always, parallel to the substrate), a significant amount constituting 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total volume of the CVD synthetic diamond material.

There are already ways of producing CVD diamond using two or more different sub-areas of growth, defined as areas having parallel dislocations, which propagate in a certain �inanam direction, and dislocation in one area apparently extend in the direction different from the direction of propagation of dislocations in a different area. Therefore, it was possible to suggest that the dislocation in the same region are not parallel to the dislocations within another area. An example of two different areas - it was a case of secondary CVD synthetic diamond layer is grown on CVD synthetic diamond substrate, and the initial direction of the growth substrate and the growth direction of the secondary layer are different (see, e.g., M. P. Gaukroger and others, Diam. Relat. Mater. 17, 262 (2008)). In this case, the substrate and the secondary layer are two different areas. Another example of different areas corresponds to the growing CVD synthetic diamond on non-oriented substrates where individual dislocations in substance and dramatic changes in their linear direction, crossing various pseudospectra growth, and dislocation within one pseudospectra correspond to dislocations in one area, and dislocation in another pseudospectra correspond to the dislocations in a different area. The effect of differing line directions of dislocations in different areas of the material contrasts with the objects of the present invention, which relate to the provision of dislocations, which are not parallel to each other within the same field of Materia�and, that is, the dislocations that intersect, forming a non-parallel grid, not dislocations in various fields CVD synthetic diamond material, which do not actually intersect and form two separate parallel mesh in different areas of the material.

X-ray topographic images recorded using the camera lang, adapted to the x-ray source, can be used to identify dislocations in diamond. Topographic images of cross-sections recorded using Bragg reflection crystallographic plane {533}, allow for sampling in such a way that the plane of the scanned x-ray beam is in the range of two degrees relative to the {001} plane. Topographic images of cross-sections recorded using Bragg reflection {008}, to allow sampling of the {110} plane. Topography x-ray cross-sections and projections were used to diamond by author Lang, and others (see, e.g., I. Kiflawi et al Phil. Mag., 33 (4) (1976) 697 and A. R. Lang, J. E. Field. Ed., "The Properties of Diamond, Academic Press, London (1979) pp. 425-469). And sectional and a projection x-ray topographic image can be used to measure the linear directions of dislocations and the greater part of the volume, which dislocation take. The angles between dislocations and between the growth direction and lineinitializeex dislocation can be set to display two or more sectional topogram, for example, but not exclusively, displaying plane {100} and {110}. Most of the volume can be set or through projection topographic images, or by two or more sectional tomogram.

Contrast observed in an x-ray topographic image caused by the deformation introduced into the crystal lattice dislocation or ligament dislocation. Preferably, the scanning area between 10 nm2and 1 mm2single crystal CVD synthetic diamond object containing a non-parallel dislocation, it is possible to establish that it possesses a density of bundles of dislocations/dislocation in the range of 10 to 1×108cm-2. Within x-ray topographic images it is not possible to distinguish a dislocation from a bunch of dislocations, but the strong contrast in the image usually means the last case. Therefore, the terms "disposition" and "bundles of dislocations are often used interchangeably. Projection topographic images recorded by moving the sample through the x-ray beam can be analyzed to provide information regarding the number of dislocations across the sample (see, e.g., M. P. Gaukroger et al, Diamond and Related Materials 17 262-269 (2008)).

In addition to the concentration of dislocations, linear direction and/or the burgers vector (i.e., the type of dislocation) can also play an important rol�. It should be noted that this type of dislocation refers to the angle of the burgers vector relative to the linear direction of the dislocation. In edge dislocations, the burgers vector and dislocation line are at right angles to each other (i.e., 90°). In screw dislocations they are parallel (i.e. 0°). In mixed dislocations, the burgers vector is oriented at an acute angle between these extreme values. The type of dislocation was determined by x-ray analysis topograms recorded for many different reflections (see, e.g., M. P. Gaukroger et al, Diamond and Related Materials 17 262-269 (2008)). This type of analysis is applicable for the description of individual dislocations, but in the case where there may be bundles of dislocations, the analysis can be complicated because the bundle can contain more than one type of dislocations. In this case, the bundle of dislocations of another type, without a single predominant type not characterized as a specific type of dislocation and is not taken into account in the analysis.

Different types of dislocations have different degrees of atomic reconstruction and therefore to a greater or lesser extent bring loose connection that may contribute or affect the optoelectronic properties. For example, the presence/absence of blue dislocation photoluminescence in CVD synthetic diamond material is likely to be Oprah�importance and line direction of the dislocation, and its burgers vector, that is, some types of dislocations exhibit luminescence, and some don't. This further emphasizes the interest of inventors to select and control the type of dislocations in CVD synthetic diamond material.

It should be understood that each dislocation has a tendency to spread along a perfect straight line, but rather deviates from it due to the steps formed during growth of CVD synthetic diamond layer, resulting in the formation of terraces and steps of growth. The staircase effect on dislocations in CVD synthetic diamond described by Martineau et al. in Phys. Status Solidi C 6, No. 8, 1953-1957 (2009). Accordingly, it should be understood that the direction in which extends dislocation, is here considered as the average direction along a significant length of dislocation, where a significant length is preferably at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total length of the dislocation and/or equal to or more than 50 μm, 100 μm, 250 μm, 500 μm, 1000 μm, 1500 μm, or 2000 μm in length.

Single crystal CVD synthetic diamond layer (for example, oriented in (110)) may contain a significant number of non-parallel dislocations, oriented within 20°, 10° or 5° relative to the linear direction <100>, and referred to a significant number equal to at IU�e, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total number of visible dislocations, for example, in topogram section or projection. If necessary, less than 70%, 60%, 50%, 40%, 30%, 20% or 10% of dislocations within a significant amount of single-crystal CVD synthetic diamond layer are oriented within 20°, 10° or 5° relative to the linear direction <110>, and referred to a significant number is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total number of visible dislocations, for example, in topogram section or projection. Dislocation <100> or can be mixed 45°-mi, or marginal type. In accordance with some configurations, at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the total number of characterized of dislocations oriented along (110) layer are 45°s dislocation of the mixed type and/or dislocations of edge type. In accordance with certain configurations less than 70%, 60%, 50%, 40%, 30%, 20%, 10% or 5% characterized dislocations within a significant amount of single-crystal CVD synthetic diamond layer represent the <110> 60°s dislocation of the mixed type. In addition, in accordance with certain configurations less than 70%, 60%, 50%, 40%, 30%, 20%, 10% or 5% characterized dislocations within a significant amount of single-crystal CVD synthetic diamond layer can be <110gt; screw or <110> boundary value type.

It is important to note that the above percentages of the types of dislocations relative to the total number of dislocations, which are characterized as having a specific type with this method of analysis. For example, as previously indicated, a bunch of dislocations, which contains many different types of dislocations, without a single predominant type, will not be characterized using a topographic method of analysis and, thus, will be rejected as recharacterized. It should be clear for the person skilled in the art and is discussed in more detail below.

The burgers vector of a dislocation can be classified by gathering data from multiple x-ray projections topogram. To obtain the projection topographic images you want to move the sample through the x-ray beam to expose its full volume and you want to move the tape, respectively, to maintain its position with respect to the sample. X-ray projection topographic images using different Bragg reflection, are used for the classification of the burgers vector associated with the sign of the dislocation in the x-ray topographic image. This method is summarized in the work of M. P. Gaukroger et al. in Diamond and Related Materials 18 (2008) 262-269. In diamond it is assumed the burgers vector <110>. Usually�ntrast associated with the disposition of the characteristic depends on the angle between the burgers vector and the atomic layers, responsible for this diffraction. To a good approximation associated with the deployment of the sign of the invisible in this x-ray topographic image, if the burgers vector is parallel to the diffraction plane, has a strong contrast, if the burgers vector is perpendicular to the diffraction plane, or has an intermediate contrast, if the burgers vector is under an intermediate angle between 0° and 90° relative to the diffraction plane, and the contrast is stronger when the burgers vector is closer to 90°, and weaker when the burgers vector is closer to 0°. This means that different types of dislocations having different directions of the burgers vector, will have different contrasts in specific topographic image. In addition, the only symptom of a dislocation with a specific direction of the burgers vector, show different contrast in different topographic images taken in different directions relative to its burgers vector.

In this way it is possible to set the burgers vector associated with this dislocation of the trait and, thus, to characterize its type. The sign of the dislocation, which contains many dislocations with different burgers vectors, with no predominant direction, will tend to have intermediate contrast in the various�graficheskih images taken in different directions, and will not be characterized.

In practice, other factors must be taken into account. Reflection should also be selected so as to achieve a suitable prospect for a clear visualization of dislocations and to establish their position among the distinguished topograms. Although the reflection of the {111} represents a good reflection for normal growth on substrate (100), it may not be the optimal reflection in other cases. For this work it was found that problematic use of reflection {111} to achieve the proper perspective, such that separate associated with dislocation of the signs were clearly resolved. Therefore, it was selected reflection {220}, because it gives approximately "flat" view of the sample (approximately 14° off-axis), and this facilitates the recognition of the same dislocation in different types. If there are four projection topographic images using reflection {220}, setting the growth direction [110], four topographic images are recorded using a reflection from(202), (022), (02-2) and (20-2) planes. If the burgers vector lies in one of the diffraction planes {220}, then we can expect that the dislocation will have a strong contrast in one topographic image, the average contrast in adjacent topogram and will be invisible in the fourth. If associated with the dislocation p�isnack is a pure edge or pure screw, we expected the average contrast in all four topogram. Then you want to obtain the topographic image, using the reflection in the (110) plane growth to discern the signs of the two topogram. Using this method, it is possible to classify the different dislocation types. For a bunch of dislocations containing various types of dislocations, and ligament can produce intermediate contrast in all topographic images and may be unclassifiable. Such indication of dislocations is excluded from the analysis. For the case of bundles of dislocations mainly one type of combo will have a different contrast in different topogram in accordance with the predominant type of dislocations within the ligaments and will be classified. Such sign dislocations accounted for as a single dislocation in order of numerical analysis. To establish the presence or absence of associated with dislocation of the symptom in multiple x-ray topogram should accurately align associated with the dislocation contrast in different images. This may be performed manually by visual inspection or can be automated using a suitable computer algorithm.

Implementations of the invention based on the understanding of the present inventors that there are two mechanisms by which can emerge dislocation CVD synthetic diamond: (i) threading dislocation from the primary layer (the substrate) to secondary CVD synthetic diamond layer; and (ii) dislocations originating at the interface between the surface of the substrate and CVD synthetic diamond layer or due to surface defects or due to other reasons (for example, due to the mismatch of lattice parameters). To some variants of implementation of the present invention has led to the realization that growing on the surfaces of (110) leads to a significantly higher number of scenarios for the formation of dislocations and in accordance with paragraph (i), and in accordance with paragraph (ii).

In respect of paragraph (i), certain embodiments of the invention, based on the analysis performed by the inventors in the study of growth on the surfaces (110), a vertical incision primary (001) CVD layer for the formation of (110) faces of growth and cultivation on this face. The authors recognize that there are geometric considerations that can lead to one type of dislocations in the primary (001)-grown layer, passing through and being converted into the second type of dislocations in the secondary (110)-grown layer, by changing the linear direction, but maintaining the burgers vector, as shown in Table 2. From this table it can be seen that it is possible to create secondary CVD layer that contains only certain types of dislocations and/or linear direction. Eg�measures it is possible to create a CVD layer, which contains 60°s, mixed <110> dislocation, if the primary (001)-grown layer contains 45°s mixed dislocations. Conversely, it is possible to create the secondary (110)-grown layer, which contains 45°s, mixed <100> dislocation, if the primary (001)-grown layer contains edge dislocations. Thus, it was demonstrated that it is possible in a controlled manner to create a certain linear direction and types of dislocations in the secondary CVD layer, which are determined by the type of dislocations in the primary layer. This ability to enter with the growth of certain types/linear directions of threading dislocations, and not the other, enables the separation and study of various types of dislocations (edge, screw or mixed). This provides significantly greater opportunities to sense the controlled formation of dislocations than the standard cultivation on substrates (001).

Table 2
(110) growth on (001)-grown vertically cut primary CVD layer showing the different types of threading dislocations, if the dislocations are located in a linear direction [110] and [010] respectively
Primary layerLinear eg�quench The burgers vectorTypeSecondary layerLinear directionType
(001)[001][101]Mixed 45°-th(110)[110]Misc 60°-th
(001)[001][011]Mixed 45°-th(110)[110]Misc 60°-th
(001)[001][110]Regional(110)[110]Screw
(001)[001][110]Regional(110)[110]Regional
(001)[001][101]Mixed 45°-th(110) [010]Regional
(001)[001][011]Mixed 45°-th(110)[010]Mixed 45°-th
(001)[001][110]Regional(110)[010]Mixed 45°-th
(001)[1-10]Regional(110)[010]Mixed 45°-th

Referring to the above-mentioned item (ii), the authors of the present invention noticed that the growth on the surface (110) gives even more opportunities for controlled formation of dislocation for those dislocations that are formed at the interface of CVD/substrate. The authors of the present invention noticed that when using a good finishing of the substrate (110) (110) growth, under certain conditions of growth, discussed below, can be meshed non-parallel dislocations with the direction <100>, some of which originate on �employee section between the substrate (110) and the secondary layer. However, if you use poor finishing of the substrate, regardless of growth conditions, there is a grid of parallel dislocations with the direction <110>. Bad finishing of the substrate leads to a small cracks on the surface of the substrate, which act as sources of dislocations, and the authors noticed that these dislocations emerging at the surface defects have a certain type that grow in configuration parallel to the direction <110>.

It is therefore important to carefully handle the surface of the substrate, to avoid the emergence of these parallel dislocations.

Some methods of forming the single crystal CVD synthetic diamond layer includes: providing a single crystal diamond substrate with the face (110) growth, having a density of defects equal to or less than 5×103defects/mm2as identified analytical plasma etching; and growing a layer of single crystal CVD synthetic diamond (110) face growth with respect to the growth rate of <110> to the growth rate of <001> below limit, whereby is formed the grid is non-parallel dislocations in the layer of single crystal CVD synthetic diamond. Face (110) growth can be formed from single crystal CVD synthetic diamond single crystal natural diamond or single crystal HPHT (high pressure, high temperature) synthetic diamond. For example, single-crystal CVD synthetic diamond wafer, single crystal natural diamond or HPHT monocrystalline synthetic diamond plate can be processed to form a face (110) growth, having a density of defects equal to or less than 5×103defects/mm2as identified analytical plasma etching. Processing may, for example, include the cutting and polishing and/or plasma etching.

In accordance with some embodiments of the implementation can be used a multi-stage growth process. For example, some methods contain:

providing a monocrystalline diamond substrate containing the surface (001) growth, having a density of defects equal to or less than 5×103defects/mm2as revealed analytical plasma etching;

growing the first layer of single crystal CVD synthetic diamond on the surface of the (001) growth;

vertical cutting the first layer of single crystal CVD synthetic diamond to form a face (110) growth;

the processing of faces (110) growth so that it had a defect density less than 5×103defects/mm2as revealed analytical plasma etching; and

growing the second layer monocr�crystal CVD synthetic diamond (110) face growth with respect to growth rate < 110> to the growth rate of <001> below limit, whereby is formed the grid is non-parallel dislocations in the second layer of single crystal CVD synthetic diamond.

Fig.1 shows a block diagram of the sequence of operations, showing how different types and orientations of dislocations can be implemented in CVD synthetic diamond material, in particular selected path by which can be achieved grid non-parallel dislocations within the CVD synthetic diamond material. Fig.1 primary layer refers to a single crystal CVD synthetic diamond layer (001) grown on a monocrystalline diamond substrate (001). The primary layer is then cut vertically along the diagonal to form a monocrystalline diamond substrate (110) on which is grown a secondary layer (110) single-crystal CVD synthetic diamond.

It should be noted that, when it comes to single-crystal diamond substrate (001), refers to the substrate, oriented so as to have a crystallographic (001) plane as a growth surface. However, the surface growth may not be perfectly aligned with the oriented plane (001). Because of the limitations on the processing, the actual orientation of the growth surface may differ from the ideal read more�orientation to 5°, and in some cases up to 10°, although it is less desirable because it adversely affects the reproducibility. Similar comments also apply to single-crystal diamond substrate (110).

Fig.1 emphasized that the types of dislocations found in the primary layer, depend on the quality of the surface (001) of the growth substrate on which is grown the primary layer. If the surface is (001) growth substrate has a poor surface finish, mixed 45°s dislocations are formed in the <001> direction (i.e. parallel to the grid mixed 45°'s dislocations, oriented vertically in the direction of growth). If the surface is (001) growth substrate has good surface finishing, edge dislocations are the predominant type formed in the <001> direction (i.e., parallel to the grid, oriented vertically in the direction of growth).

Fig.1 also shows that the type and orientation of dislocations found in the secondary layer may depend on: (i) type of dislocations in the primary layer, (ii) finishing the surface of the substrate (110) made of a primary layer, and (iii) the growth rate used for the secondary layer.

If initially for the growth of the primary layer is provided to poor finishing of the surface of the growth substrate, leading to parallel the grid <100> mixed 45°'s dislocations, and then the first�tion layer is cut vertically along the diagonal, to form a (110) single crystal diamond substrate on which is grown a secondary layer, is formed parallel to the grid is oriented along <110> dislocation of the mixed 60°type. This is an undesirable option.

Conversely, if initially provided a good surface finish growth substrate for growing the primary layer, leading to parallel the grid <100> edge dislocations, and then the primary layer is cut vertically along the diagonal to form a (110) single crystal diamond substrate on which is grown a secondary layer, as the authors of the present invention installed, there are many possibilities, as shown in Fig.1. If monocrystalline diamond substrate (110), on which is grown a secondary layer) has a poor surface finish of the substrate, the surface defects will again lead to the formation of dislocations mixed 60°-th type oriented parallel to <110>. If monocrystalline diamond substrate (110) are well prepared, suddenly there are two possibilities, which depend on the growth rate of the secondary layer. If the secondary layer is used for relatively high growth rate <110> to the growth rate of <001>, is formed parallel to the grid is oriented�s < 110 > screw dislocations and/or marginal type. Alternatively, if the secondary layer is a relatively low ratio of the rate of growth of <110> to the growth rate of <001>, is formed non-parallel grid oriented along <100> dislocation of the mixed 45°and/or boundary value type.

It can be important to avoid surface defects on the substrate (110), since they lead to the creation of new dislocations in the secondary layer, which adopt a configuration with the lowest energy is the core of dislocations, i.e. <110> mixed 60°s (similar to <100> mixed 45°-th dislocations generated during growth on poorly prepared standard substrates (001)). The prevention of the birth of <110> mixed 60°'s dislocations in the secondary layer defines the cultivation of well cooked on the substrate (110), for example, by polishing with the mowing and the use of pre-etching to cultivation, which prevents the formation of macroscopic holes.

Even when the substrate (110) to the secondary layer cooked to perfection and there are only minor surface defects, there are still some threading dislocations that originate at the interface between the substrate (110) and secondary CVD synthetic diamond layer. Beyond theory and excluding in�separarate the mechanism of nucleation of dislocations, we can assume that these dislocations can be caused by a mismatch of lattice parameters between the primary and secondary layers. Was observed, even though these dislocations occur at the interface in a similar manner as those that are the result of poor preparation of the substrate that these dislocations are taking a non-parallel configuration of the grid oriented along <100> mixed 45°-s and edge dislocations as opposed to those that are the result of poor preparation of the substrate. Consequently, these dislocations do not have to remove to reach the variants of implementation of the present invention.

In light of the above, it is obvious that to achieve a non-parallel grid of dislocations in single crystal CVD synthetic diamond in accordance with some embodiments implementing the present invention requires: (i) careful preparation of the initial substrate (001) to the cultivation of primary diamond layer (001); (ii) careful preparation of the substrate (110) formed from the primary layer; and (iii) careful control of the growth rate of secondary diamond layer (110).

Beyond theory, previously described results can be justified as follows.

CVD single crystal diamond growth is usually determined by kinetic, not thermodynamic�RCM processes. However, the balance between kinetic and thermodynamically controlled process can be modified by changing the growth parameters. For example, growing at low growth rate <110> to the growth rate of <001>, growth, more likely to be determined thermodynamic and not kinetic factors and Vice versa for high growth rate <110> to the growth rate of <001>.

With respect to the foregoing, the authors present invention found that the "low" ratio of the growth rate of <110> to the growth rate of <001> can be less than 1.0, and the ratio can be more than 1.0. The ratio of the growth rate of <110> to the growth rate of <001> can be controlled so as to be equal to or less than 1,0, 0,8, 0,6, 0,4, or 0.2. However, specialists in the art will see that various conditions such as different temperature of the growth surface of the diamond will affect the features of the kinetics/thermodynamics, and can essentially change the definition of "low" and "high". The ratio of the growth rate of <110> to the growth rate of <001> much depends on the growth rate of <110>.

Modification of the ratio of the rate of growth of <110>:<001> considered a way known to specialists in this field of technology. Previously published studies examine the modification of pairs�meters of growth, for example, doping with nitrogen, boron doping, and substrate temperature and their relative impact on the growth rate in different crystallographic directions. Such a relationship of the rate of growth is usually characterized in the expressions of α, β and γ parameters. However, for purposes of the present invention, this is too complex and is used in this case simply the ratio of the growth rate of <110>:<100>.

The cultivation of the secondary layer (110) synthetic CVD diamond at a sufficiently small ratio <110>:<100> growth rate allows the dislocations to adopt a configuration that minimizes their total energy per unit length. That is, the dislocation germinate at lower energy nuclei per unit length (thermodynamically more favorable). We can expect that the <110> mixed 60°s, the participants will have the lowest energy per unit length. Therefore, at small the growth rate of <110>:<100> these <110> mixed 60°s, the participants will still grow if you have the possibility to create them, or germination <100> mixed 45°'s dislocation from the primary layer to the secondary layer, or poor preparation of the substrate surface (110) produced from the primary layer. Therefore, it is desirable to remove all sources of <110> mixed 60°'s dislocations. As already mentioned, this is both correct� preparation of the substrate, on which the primary layer is grown to minimize the <100> mixed 45°s of the dislocation in the primary layer, and also a good preparation of the substrate surface (110) produced from the primary layer.

In the absence of the created <110> mixed 60°'s of dislocations grows non-parallel grid oriented along <100> and mixed boundary value 45°'s dislocations. Oriented along <100> regional and mixed 45°s of the dislocation propagated at an acute angle of approximately 45° from the direction of growth and lead to non-parallel grid of dislocations. This was achieved through a combination of correct processing of the primary and secondary substrates and growth parameters of the secondary layer.

For large relations, the growth rate of <110>:<100> kinetics of growth process dominates thermodynamics. When the processes of growth are largely determined by kinetics, not thermodynamics, dislocation just go back to the configuration with the shorter length, which means that they follow the growth direction, i.e. the direction <110>, in this case, the secondary layer. Therefore, at high speeds of growth, preferably will germinate dislocation with greater energy the core of the dislocation. They include <110> screw-in <110> edge dislocations, as shown in Fig.1.

Below in this specification Pref�converges more details about how to prepare the surface growth and how to control the speed of growth to accomplish the purposes of the present invention. It should be noted that the ratio of the specific growth rate required to achieve a non-parallel grid of dislocations depends on the chemical conditions of cultivation used in the CVD process, and a few changes according to specific chemical conditions of cultivation. However, it should be understood that the specialist in the art can optimize the ratio of the rate of growth, performing a series of test cycles at different ratios of speed of growth for your organization process to find the ratio of the speed of growth, which are close to but not in excess of thermodynamic limit at which dislocations are switched from the more thermodynamically stable <100> orientation to kinetically due to the <110> orientation of the secondary stage of growth, based on the substrate (110), which contains oriented along <100> dislocations of edge type. Specialists in the art will know about the factors that alter the ratio of the rate of growth. They include, for example, the temperature of diamond growth, the proportion of carbon in the gas phase and the presence of some impurities, such as nitrogen and boron.

Fig.2 shows the steps of the method are included in the formation of the CVD synthetic�th diamond material, having non-parallel grid of dislocations in accordance with a variant implementation of the present invention and possible alternative ways of synthesis that lead to parallel the grid of dislocations. Initially provided (001) single crystal diamond substrate 2. It can be formed from natural, HPHT or CVD synthetic diamond material. Although each of these different types of diamond material has its own distinctive features and, therefore, are recognized as distinguished, the main feature of this substrate is that the surface growth is carefully prepared, so as to have a good surface finish.

Under good surface finish refers to the surface having a density of defects equal to or less than 5×103defects/mm2as revealed analytical plasma etching. The density of defects are most easily classified by optical evaluation after using a plasma or chemical etching, optimized for detection of defects (called plasma-chemical analytical etching) using, for example, a brief plasma etching described below type.

Two types of defects can be detected:

1) Inherent in the material of the substrate of this quality. In the�nom natural diamond density of these defects can be as low 50/mm2with more typical values constituting 102/mm2although in others it may be 106/mm2or more.

2) Those that formed as a result of polishing, including dislocation structure and microcracks forming technological traces along the lines of polishing. Their density can vary greatly according to the sample, with typical values in the range of approximately 102/mm2and more than 104/mm2in a poorly polished areas or samples.

The preferred low density of defects is such that the density of the surface signs of etching related to the defects, is less than 5×103/mm2and more preferably less than 102/mm2. It should be noted that a simple polishing the surface to obtain a small surface roughness does not necessarily meet these criteria, because the analytical plasma etching detects defects on the surface and directly below the surface. In addition, analytical plasma etching can reveal internal defects, such as dislocations, in addition to surface defects, such as micro-cracks and surface features that can be removed by simple polishing.

The level of defects on the substrate surface, and below it, on to�ora is a growth of CVD, may, therefore, be minimized by careful selection and careful preparation of the substrate. Under "cooking" in this case refers to any processing applied to the material received from the mine (in the case of natural diamond) or synthesis (in the case of synthetic material), since each stage can affect the density of defects within the material in a plane which ultimately forms the surface of the substrate when preparing her as the substrate is completed. Specific processing steps may include conventional diamond processing, such as mechanical sawing, grinding and polishing (in this application specifically optimized for low defect levels), and less conventional methods, such as laser processing, reactive ion etching, ion beam milling or ion implantation and methods of inverse lithography, chemical/mechanical polishing, and liquid chemical treatment and plasma treatment. In addition, the measured needle profilometer surface RQpreferably measured by more than 0.08 mm in length, should be minimized, and typical values prior to any plasma etching should be no more than a few nanometers, less than 10 nanometers. The value of RQpresented�a splash zones standard deviation of surface profile from the plane (for a Gaussian distribution of surface heights, RQ=1,25 Ra. For definitions, see for example, "Tribology: Friction and Wear of Engineering Materials", IM Hutchings, (1992), Publ. Edward Arnold, ISBN 0-340-56184).

One of the specific ways to minimize surface damage to the substrate is the inclusion of in situ plasma etching on the surface, which must be homoepitaxially diamond growth. In principle, this etching does not necessarily have to be neither in situ nor directly to the growth process, but the greatest advantage is achieved if it is carried out in situ, as it manages to avoid any additional risk of physical damage or chemical contamination. The in situ etching is also usually the most convenient, when the process of cultivation based on the use of plasma. Plasma etching can use similar conditions for deposition or in the growing process of a diamond, but in the absence of any carbon-containing source gas, and usually at somewhat lower temperature, in order to have a better control of the speed of etching. For example, it may consist of one or more of the following:

(i) Oxygen etching, using mainly hydrogen and, if necessary, a small amount of Ar and required a small amount of O2. Typical conditions of oxygen etching pressure of 50-450×102PA, and the etching gas having containing�their oxygen of 1-4%, the amount of argon from 0 to 30% and the balance hydrogen, all percentages are volume, with a substrate temperature 600-1100°C (more typically 800°C) and with a typical duration of 3-60 minutes.

(ii) Hydrogen etching, which is similar to (i), but in the absence of oxygen.

(iii) Can be used alternative means of etching, is not solely based on argon, hydrogen and oxygen, for example, those that use Halogens, other inert gases or nitrogen.

Typically, the etching comprises etching with oxygen followed by hydrogen etching and then move directly into the synthesis of the introduction of gas-carbon source. Time/temperature etching are selected to give the option to remove remaining surface damage from the treatment and to remove any surface contaminants, but without formation of a too rough surface and without excessive etching along extended defects such as dislocations that intersect the surface and thus provoke a deep fossa. Because the aggressive etching, it is particularly important to this stage, because the design of the camera and the choice of materials for its components such that the material is not tolerated by the plasma from the chamber in the gas phase or to the surface of the substrate. Hydrogen etching after oxygen, water�tion etching, is less specific for defects of the crystal, rounded angularity caused by oxygen etching, which has an aggressive effect on such defects, and providing a smoother, better surface for subsequent growth.

Preparing accordingly the surface of the growth on (001) single crystal diamond substrate 2, as shown in Fig.2, Phase A includes the CVD growth of the primary layer oriented to (001) single-crystal CVD synthetic diamond material 4 on the substrate 2. This layer will contain oriented along <100> dislocations of edge type, as previously discussed in connection with Fig.1.

At the Stage B primary layer oriented to (001) single-crystal CVD synthetic diamond material 4 is cut vertically along the diagonal (indicated by the dotted lines in Fig.2) for receiving (110) single crystal diamond plate 6, as shown in Step C. This can be achieved using laser. Oriented in (110) single crystal diamond plate 6 can then be used as the substrate on which is grown a secondary layer of single crystal CVD synthetic diamond material 8. Subsequently, a secondary layer of single crystal CVD synthetic diamond material may be grown on the growth surface of the substrate (110).

Surface growth (110) of the substrate 6 to be processed in a similar manner as described relative to the substrate (001), to get a good surface finish. Under good surface finishing again means a surface having a density of defects equal to or less than 5×103defects/mm2, and more preferably below 102/mm2as revealed analytical plasma etching. However, excessive etching of the substrate will lead to the pits formed on the substrate surface. Typically these pits consist of (001) and (111) crystallographic planes, and if they will have a depth of more than 5 microns, they will lead to the creation of new dislocations in the (110) layer, which will take the configuration with lowest energy (that is <110> mixed 60°s). This is also manifested in the pits on the final growth surface. The conditions under which it happens excessive etching, vary greatly in accordance with the geometry of the reactor, but it will happen if the etching is performed excessively long duration (several hours) or in excess capacity and/or temperatures.

Different possibilities for the types of locations and orientations shown in the Stages D, E and F in Fig.2. In accordance with Step D, if the initial (001) diamond substrate was not well cooked, p�ivoda to < 100 > mixed 45°-th dislocations in the primary layer, parallel grid oriented along <110> mixed 60°-dislocations's 10 is formed in the secondary layer. Also in accordance with Step D, if a (110) diamond substrate was not well cooked, parallel grid oriented along <110> mixed 60°-dislocations's 10 can emerge in the secondary layer. In accordance with Step E, if the initial (001) diamond substrate was well cooked, leading to <100> edge dislocations in the primary layer, but uses a large ratio of the rate of growth of <110> to the growth rate of <001> for the formation of a secondary layer 8, the parallel grid oriented along <110> screw and edge dislocations 12 is formed in the secondary layer. Conversely, in accordance with Step F, if the initial (001) diamond substrate was well cooked, leading to <100> edge dislocations in the primary layer, and used a relatively small ratio of the rate of growth of <110> to the growth rate of <001> for the formation of a secondary layer 8, the non-parallel grid oriented along <100> mixed 45°'s and edge dislocations 14 is formed in the secondary layer.

Growing on (110) surface, as considered here, provides a greater variety of types of dislocations in the secondary layer than grown on (001) surfaces.Possible orientations and types of dislocations in the secondary (110) layer are summarized below.

The linear direction of the Type of dislocation (assuming the burgers vector <110>)

[100] Edge

[100] Misc 45°-th

[110] Misc 60°-Aya (the most favorable in terms of the energy kernel)

[110] Boundary

[110] Mixed 45°-th

[110] Screw (least favorable in terms of the energy kernel)

These different types and orientations of dislocations in the secondary layer is also shown in Fig.3 and 4. Fig.3 shows the types of dislocation, which may extend in a direction parallel to the growth direction in (110) CVD synthetic diamond layer. The growth direction corresponds to the direction <110>, which is the vertical direction in the drawings. Dislocations are propagated from the boundary or 45°'s mixed dislocations in primary CVD layer (the bottom layer in each of the drawings). Fig.4 shows the types of dislocations, which propagate at an acute angle relative to the direction of growth in (110) CVD synthetic diamond layer. Of a dislocation propagated in the direction <100> at an angle of approximately 45° to the vertical growth direction. And again, dislocations propagate from the boundary, or 45°'s mixed dislocations in primary CVD layer. Thus in Fig.3 shows dislocations, which are formed in accordance with Steps D and E, as previously described relative to Fig.2, while in Fig.4 shows the dislocation, which is grouped�tsya in accordance with Step F, as previously described relative to Fig.2.

Most energetically favorable dislocation (the lowest energy of the nucleus) in the secondary layer is a <110> mixed 60°s of the dislocation. Oriented along <110> mixed 60°s of the dislocation in the secondary layer are the result of <100> mixed 45°'s dislocations in the primary layer or poor preparation of the surface (110) substrates, formed from the primary layer. In General mixed types of dislocations usually have lower energy than edge or a screw dislocation. Oriented along <100> mixed 45°s of the dislocation in the primary layer follow from growing on poorly prepared substrates. The cultivation of the primary layer on a well prepared surface (001) substrate with good finishing treatment will lead to very little <100> mixed 45°-th dislocations in the primary layer and therefore will contribute to minimize the number of <110> mixed 60°'s dislocations in the secondary layer. Dislocations are also created at the interface between the secondary layer and the substrate (110) produced from the primary layer. If the cooking surface of the substrate (110) is good, then the dislocations generated at the interface will only dislocations <100> or regional mixed 45°-th type. If the cooking surface of the substrate (110) is bad, <110> mixed 60°s dis�okazii will be created additionally. Minimizing the number of <110> mixed 60°'s dislocations in the secondary layer created at the interface, can therefore be achieved by treatment of the substrate (110) to a higher standard. If both of these steps are performed to eliminate the <110> mixed 60°'s dislocations, <110> or <100> regional <100> mixed 45°s, or <110> screw dislocation will germinate and be selected by adjusting the parameters of the growth process.

In light of the above it is obvious that variants of realization of the present invention allows for: (i) to control for the primary layer removal <100> mixed 45°'s dislocations in order to remove the <110> mixed 60°s of the dislocation in the secondary layer; and (ii) to monitor the cooking surface of the substrate (110) produced from the primary layer to avoid the formation of <110> mixed 60°'s dislocations at the interface between the substrate and the secondary layer. The growth rate can then be monitored in the secondary layer so that the formed single-crystal CVD synthetic diamond material has a non-parallel grid of dislocations containing <100> mixed 45°s and/or <100> edge dislocations.

In addition to controlling the orientation and type of dislocations, which can be availed in single crystal CVD synthetic diamond material,�, through the use of surface treatments of the substrate and controlling the parameters of the CVD growth, also it is possible to control the density of dislocations generated in the material. Usually a lower concentration of defects on a growth surface of the substrate leads to low density of defects in CVD synthetic diamond material grown on the substrate. In addition, careful control of CVD chemical and technological parameters, such as pressure, substrate temperature, reagent consumption, and plasma temperature can reduce the density of growth defects in CVD synthetic diamond material. For example, the primary layer (001) single-crystal CVD synthetic diamond may contain a dislocation density in the range from 10 cm-2to 1×108cm-2. Moreover, the secondary layer (110) single-crystal CVD synthetic diamond may contain a dislocation density in the range from 10 cm-2to 1×108cm-2.

Options for the implementation of the present invention also provide the possibility of separation and study of certain types of dislocations (e.g., <110> 60°'s mixed dislocations or <100> 45°'s mixed dislocations), evaluating their fundamental properties and to examine which types of dislocations cause more or less harm in the sense of working parameters of the devices. In this case the variants of implementation of the present invention open up the possibility of providing mono�ristalliceski CVD synthetic diamond products in which the concentration, distribution, orientation, and type of dislocations are carefully selected and controlled to minimize their impact on material properties, or even to improve the properties of the material. These material properties include optical birefringence, electronic properties (electrical breakdown and μ), luminescent properties and mechanical properties (wear and hardness).

Options for the implementation of the present invention can provide a single crystal CVD synthetic diamond product containing a significant amount, having the dislocation density in the range from 10 cm-2to 1×108cm-2from 1×102cm-2to 1×108cm-2or from 1×104cm-2to 1×107cm-2. Alternative or additionally, a single crystal CVD synthetic diamond product can have a birefringence equal to or less than 5×10-4, 5×10-5, 1×10-5, 5×10-6or 1×10-6. The material may also have only a replacement of atomic nitrogen with a concentration in the range of from 0.001 to 20 ppm (part per million), preferably from 0.01 to 0.2 ppm.

Although the previous consideration largely treated oriented on a {110} growth, the authors present invention also found that similar comments apply in respect of any CVD growth on read more�based on {113} substrates. In fact, the initial results indicate that there may be some preference for the implementation of the invention oriented on {113} substrates, since the growth rate can be increased while maintaining a non-parallel orientation of dislocations. It was found that can be made of thick, high-quality single-crystal CVD synthetic diamond material containing a grid of non-parallel dislocations having a crystallographic orientation {113}. One major difference between the orientation {110} and orientation {113} is that some {110} of implementation options net non-parallel dislocations is visible in x-ray topographic image of the cross section, but not in the conditions of fluorescent techniques, whereas for some {113} variants of implementation of the mesh is non-parallel dislocations is visible in the conditions of fluorescent techniques, but not in x-ray topographic image of the cross section. This is so because of the dislocation in some linear directions emit blue fluorescent light, although other linear directions this is not happening. For {113} crystallographic variants of realization of the linear direction of dislocations in non-parallel grid of dislocations such that they emit blue fluorescent light, whereas for {110} of implementation options cu�stilografiche line direction of the dislocations in non-parallel grid of dislocation is they do not emit blue fluorescent light.

Some examples of single-crystal CVD synthetic diamond layer formed in accordance with the ways discussed here, is shown in Fig.5-8 and discussed below.

EXAMPLE 1

Was selected 1b UPHT diamond plate synthetic type with a pair of approximately parallel major faces within approximately 5° of (001) orientation. The plate was made in the form of a square substrate, suitable for homoepitaxial synthesis of single-crystal CVD synthetic diamond material by a process comprising the following steps:

(i) laser cutting of the substrate for the production of plates with all facets of <100>;

(ii) grinding and polishing the main surface on which growth occurs, and grind and Polish part has a size of approximately 6.0 mm×6.0 mm and 400 μm thick, with all faces {100}.

The level of defects on the substrate surface or below has been minimized by careful preparation of the substrate, as disclosed in Patents EP 1292726 and EP 1290251. It is possible to identify defect levels imposed by the processing using the analytical plasma etching. Usually it is possible to produce a substrate in which the density of defects measurable after analytical etching, depends first sun�th from quality material and is less than 5×10 3mm-2and usually less than 102mm-2. Surface roughness at this stage was less than 10 nm in the measured area of at least 50×50 μm. The substrate was mounted on a carrier substrate. The substrate and its carrier were then introduced into a CVD reactor chamber and began etching and growth cycle, feeding the gases into the chamber as follows:

First in situ was performed by oxygen plasma etching using 16/20/600 sccm (standard cubic centimeter per second) O2/Ar/H2at a pressure of 230 Torr, the frequency of the microwave radiation of 2.45 GHz and the substrate temperature of 780°C followed by hydrogen etching, and oxygen was removed from the gas stream at this stage. Then, the first stage of the growth process was started by the addition of methane at 22 sccm. Nitrogen was added to achieve a level of 800 ppb (pounds per barrel) in the gas phase. Hydrogen was also present in the process gas. The substrate temperature at this stage amounted to 827°C. For 24 hours the methane content was increased to 32 sccm. These growth conditions were chosen to set the value of parameter α in the range of 2,0±0,2 on the basis of previous test cycles and were confirmed retrospectively by crystallographic analysis. At the conclusion of the growth period, the substrate was removed from the reactor and the CVD synthetic diamond layer removed from the substrate l�zemaj sawing and mechanical polishing techniques.

Study CVD grown synthetic diamond plate showed that it is free of twins and cracks on (001) faces and is limited to <110> parties, and sizes of postsynthesis free double peaks of (001) facets were increased to 8.7 mm x 8,7 mm.

This block was then successively treated using the same methods described previously (cutting, grinding, polishing and etching) to obtain 1b HPHT plates for the production of plates with the main face (110) and a well prepared surface with dimensions of 3.8×3.2 mm and a thickness of 200 microns. Then after installing the cultivation was carried out using the identical conditions described above, except that during the synthesis stage, the substrate temperature was 800°C, and nitrogen was not introduced as a gas-dopant. Thus was produced the CVD sample with the main face (110) and CVD unit had typical dimensions of 5.0×4,1 mm and thickness 1.6 mm.

To study the structure of dislocations for this example was recorded x-ray sectional topographic image using Bragg reflection {533} (corresponding to the section (100)). X-ray topographic image shown in Fig.5. Fig.5 shows a single crystal CVD synthetic diamond layer grown on vertically slit (110) CVD synthetic substrate in accordance with a variant implementation of the present invention, with�holding a grid of parallel dislocations. In this section dislocations form a parallel configuration, which follows the direction of growth, i.e. the [110] direction. This configuration may correspond to the Step D or Step E, as shown in Fig.2.

For the sample shown in Fig.5, the ratio of the growth rate of <110>:<001> was $ 1.1 and therefore falls into the "large" limits, when growth is more likely determined by kinetic and not thermodynamic factors. This is clear from the image that the dislocation in Example 1 form a parallel grid. It can be seen that 85% of dislocations, shown in an x-ray topographic image are between 0° and 2° relative to <110> direction of growth.

EXAMPLE 2

The substrate (110) was made identical to that described in Example 1. Growth conditions for the second stage of growth were identical to those described for Example 1, except that the substrate temperature was reduced to 70 degrees, up to about 730°C. Thus was produced the CVD sample with dimensions of 5.7×3.5 mm and a thickness of 1.4 mm. apparently, a slight change in substrate temperature reduced the ratio of the rate of growth of <110>:<001> from a large to a small value (about 0.4).

To study the structure of dislocations for this example was recorded sectional x-ray topographic image using Bragg reflection {533} (resp�relevant section (100)). X-ray topographic image shown in Fig.6. Fig.6 shows a single crystal CVD synthetic diamond layer grown on vertically slit (110) CVD synthetic substrate in accordance with a variant implementation of the present invention containing a grid of non-parallel dislocations. It is easy to see that the dislocations form a non-parallel grid and extend in a direction close to the direction [100]. This configuration may correspond to the Phase F, as shown in Fig.2.

For the sample shown in Fig.6, the ratio of the growth rate of <110>:<001> was 0.4 and therefore falls into the "small" limits, when growth is more likely determined by thermodynamic and not kinetic factors. From Fig.6 it can be seen that the dislocation in Example 2 contain non-parallel grid. The dislocations form a grid of intersecting dislocations throughout the volume of the single crystal CVD synthetic diamond layer. Dislocation spread in two directions with an angle between the first and second direction which is between 66° and 72°. 95% of the available dislocations within the entire sample volume is focused between 9° and 12° relative to the linear direction <100>. In addition, 95% of existing dislocations in the whole volume of the sample are in the range of 33° to 36° relative to <110> direction of growth. Anal�W twelve NV centers showed they were all germinated with preferred orientation in the <111> direction is out of plane relative to the (110) surface growth.

Fig.7 shows a micrograph of birefringence for CVD synthetic diamond material of Fig.6, which shows a relatively low voltage, in light of the substantial dislocation density for this sample.

Initial data also indicate that CVD synthetic diamond material, shown in Fig.6 and 7, has an increased hardness of the material. In an earlier review article by Balmer et al. (J. Phys.: Condensed Matter 21 (2009) 364221) already revealed that the tools made use of (110) orientation show less wear and have a higher resistance to cracking than those made with (001) plane. Initial data discussed here indicate new material, the new material has the advantages of (110) diamond in terms of wear resistance in combination with increased hardness (e.g., at least 100 GPA, more preferably at least 120 GPA).

EXAMPLE 3

Synthetic type 1b HPHT diamond was cut to form a plate with a pair of approximately parallel main faces in a range of approximately 5° from the (113) orientation. The main surface on which must be the growth, was further R�Ana grinding and polishing.

The substrate was mounted on a carrier substrate. The substrate and its carrier were then introduced into a CVD reactor chamber. Cycles of etching and growth were performed as described in Example 1, except that the substrate temperature was lowered to 70 degrees to approximately 730°C, as described in Example 2.

Formed of single crystal CVD synthetic diamond material were found to contain non-parallel grid of dislocations visible in the conditions of fluorescent techniques (emitting blue fluorescent light characteristic of dislocations certain crystallographic linear direction), but not in x-ray topographic image of the cross section.

Fig.8 shows the single crystal CVD synthetic diamond layers grown on oriented along {110} and {113} substrates (as described in Examples 2 and 3), in x-ray topographic image of the cross section (top) and under fluorescent methods (basis). As can be seen in the drawing, for {110} example the grid is non-parallel dislocations visible in x-ray topographic image of the cross section, but not in the luminescent image, whereas for {113} example the grid is non-parallel dislocations visible in the fluorescent image, but not in x-ray topographic image of the cross section.

Although this invention has been shown, opisano in connection with the preferred embodiments of implementation, specialists in the art it will be clear that can be made various changes in form and detail, without departing from the scope of the claims of the invention as defined in the enclosed claims.

1. Single crystal CVD synthetic diamond layer containing a non-parallel grid of dislocations, and the mesh is non-parallel dislocations contains many dislocations, forming a grid of intersecting dislocations as seen on x-ray topographic image of the cross section or under a fluorescent technique, and the layer of single crystal CVD synthetic diamond has a thickness equal to or greater than 1 μm, wherein the mesh is non-parallel dislocation stretches by volume constituting at least 30% of the total volume of the single crystal CVD synthetic diamond layer, and wherein the mesh is non-parallel dislocations contains the first set of dislocations, extending in the first direction through the single crystal CVD synthetic diamond layer, and a second set of dislocations propagating in a second direction through the single crystal CVD synthetic diamond layer, and wherein the angle between the first and second directions is in the range from 40° to 100°, as can be seen on x-ray topographic image of the cross section �in the context of the luminescent method.

2. Single crystal CVD synthetic diamond layer according to claim 1, wherein the layer of single crystal CVD synthetic diamond has a thickness equal to or greater than 10 μm, 50 μm, 100 μm, 500 μm, 1 mm, 2 mm or 3 mm.

3. Single crystal CVD synthetic diamond layer according to claim 1 or 2, containing the dislocation density in the range from 10 cm-2to 1·108cm-2from 1·102cm-2to 1·108cm-2or from 1·104cm-2to 1· 107cm-2.

4. Single crystal CVD synthetic diamond layer according to claim 1 or 2, containing the value of the birefringence equal to or less than 5·10-4, 5·10-5, 1·10-5, 5·10-6or 1·10-6.

5. Single crystal CVD synthetic diamond layer according to claim 1 or 2, wherein the single crystal CVD synthetic diamond layer is a layer with orientation {110} or {113}.

6. Single crystal CVD synthetic diamond layer according to claim 1 or 2, wherein the mesh is non-parallel dislocation stretches in volume, amounting to at least, 40%, 50%, 60%, 70%, 80% or 90% of the total volume of single-crystal CVD synthetic diamond layer.

7. Single crystal CVD synthetic diamond layer according to claim 1 or 2, in which the angle between the first and second directions is in the range from 50° to 100°, or 60° to 90°, as can be seen on x-ray topography mission�ish image section or in the conditions of fluorescent methods.

8. Single crystal CVD synthetic diamond layer according to claim 1 or 2, wherein at least, 30%, 40%, 50%, 70%, 80% or 90% of the total number of visible dislocations within the limits of the single crystal CVD synthetic diamond layer to form a grid of non-parallel dislocations as seen on x-ray topographic image of the cross section or in the conditions of fluorescent techniques, and the mentioned amount is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% from full volume single crystal CVD synthetic diamond layer.

9. Single crystal CVD synthetic diamond layer according to claim 1 or 2, wherein the mesh is non-parallel dislocations is observed on x-ray topographic image of the cross section, but not in the conditions of fluorescent techniques, or, alternatively, the grid is non-parallel dislocations is observed in the conditions of fluorescent techniques, but not on x-ray topographic image of the cross section.

10. Single crystal CVD synthetic diamond layer according to claim 1 or 2, having a hardness of at least 100 GPA, or at least 120 GPA.

11. Single crystal CVD synthetic diamond precious product containing monocrystalline diamond layer according to any preceding paragraph, wherein the single-crystal diamond layer is at least, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the p�LEGO volume of single-crystal CVD synthetic diamond jewelry.

12. The use of single-crystal CVD synthetic diamond precious jewelry according to claim 11 in optical, mechanical, luminescent and/or electronic device.



 

Same patents:

FIELD: electricity.

SUBSTANCE: invention may be used for production of cooled single element, line and matrix radiation receivers with photosensitive elements - planar photodiodes on indium antimonide (InSb). In planar photodiode on indium antimonide, containing substrate of n-type of conductivity with concentration of alloy atoms of impurity not exceeding 3·1015 cm-3 with formed in it planar p-n junction, protective film of anode oxide, passivating dielectric film and contact system, substrate surface has crystallographic orientation (111)A.

EFFECT: increasing breakdown voltage of planar photodiode due to the least stibium atomic population on the surface with crystallographic orientation.

1 dwg

FIELD: machine building.

SUBSTANCE: here is disclosed sapphire substrate with flat surface and crystallographic orientation chosen from group including orientation in a-plane, r-plane, m-plane and c-plane. Also, this substrate has nTTV approximately not over 0.037 mcm/cm2, nTTV corresponds to change of total thickness normalised relative to area of flat surface. The substrate has approximate diametre not less, than 9.0 cm.

EFFECT: production of substrates of high quality with large surface areas.

15 cl, 6 tbl, 5 dwg

FIELD: manufacturing optical devices including semiconductor optoelectronic ones.

SUBSTANCE: proposed method used for manufacturing optical and semiconductor optoelectronic devices, such as laser diodes, optical modulators, optical amplifiers, optical switching units, and optical detectors, involves device manufacture from part of chip of quantum potential well structure including stage of device chip treatment by plasma etching so as to produce elongated defects at least in part of layer covering part of device chip as stage in technology of mixing quantum potential wells for next stage of thermal annealing.

EFFECT: improved process of mixing quantum potential wells.

22 cl, 9 dwg

The invention relates to the production of semiconductor ingots and wafers, in particular silicon crystals with cyclic twinned structure

FIELD: nanotechnology.

SUBSTANCE: invention relates to nanotechnology and can be used for labelling molecules, quantum information processing, magnetometry, and synthesis of diamond by chemical vapour deposition. Crystalline diamond powder with a maximum particle size of 2 microns to 1 mm is ground by the nitrogen jet for 1-5 hours with the grinding pressure of 500 kPa to obtain the fine powder which is then milled in a planetary mill with balls of tungsten carbide. The resulting nano-ground powder is autoclaved with the mixture of hydrofluoric acid and nitric acid at a temperature of 100-200°C. The fluorescent cubic nanocrystals of diamond of predominantly circular shape are recovered by centrifugation, with a maximum size of not more than 100 nm, comprising up to 2,000 ppm alloy addition, such as nitrogen, and up to 50 ppm of impurities. The surface of the diamond nanocrystal comprises a layer of amorphous carbon.

EFFECT: obtaining diamond nanocrystals.

15 cl, 8 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing coloured diamond materials, which can be applied as precious stones or cutting instruments. Method includes stages of growing monocrystalline diamond material in accordance with CVD-technology, with diamond material having concentration of single substituting nitrogen atoms [Ns0] less than 1 ppm; initial CVD-diamond material is colourless, or, in case it is not colourless, then, according to colour gradation brown or yellow, and if it is brown according to colour gradation, then it has level G (brown) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and if it is yellow according to colour gradation, it has level T (yellow) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and irradiation of initial CVD-diamond by electrons to introduce isolated vacancies into diamond material in such a way that product of the total concentration of vacancies × way length [Vt]×L, in irradiated diamond material at said stage or after additional processing after irradiation, including annealing irradiated diamond material at temperature at least 300°C and not higher than 600°C, constitutes at least 0.072 ppm cm and not more than 0.36 ppm cm.

EFFECT: diamond material becomes fancy light-blue or fancy light greenish blue in colour.

21 cl, 4 dwg, 3 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in obtaining jewellery diamonds. method of introduction of NV-centres in monocrystalline CVD-diamond material includes the following stages: irradiation of CVD-diamond material, containing single substituting nitrogen, for introduction of isolated vacancies in concentration at least 0.05 ppm and at most 1 ppm; annealing irradiated diamond to form NV-centres from at least some of defects of single substituting nitrogen and introduced isolated vacancies.

EFFECT: invention makes it possible to obtain pink CVD-diamond material and CVD-diamond material with spintronic properties.

18 cl, 12 tbl, 7 dwg

Diamond material // 2537857

FIELD: chemistry.

SUBSTANCE: inventions can be used in chemical and jewellery industry. Nitrogen-doped diamond material, obtained in accordance with CVD technology, or representing monocrystal or precious stone, demonstrates difference of absorptive characteristics after exposure to radiation with energy of at least 5.5 eV, in particular UV radiation, and thermal processing at temperature 798 K. Defects into diamond material are introduced by its irradiation by electrons, neutrons or gamma-photons. After irradiation, difference in absorptive characteristics decreases.

EFFECT: irradiated diamond material has absorption coefficient lower than 0,01 cm-1 at 570 nm and is capable of changing its colour.

18 cl, 7 dwg, 11 tbl, 15 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of alloys diamonds to be used in electronics and instrument making s well as jewellery stones. Alloyed diamond is produced by chemical deposition of gas phase on substrate in reaction chamber 2. Alloying solid-state component 7 is placed in alloying chamber 3. The latter has at least three connection flanges. Two of them are designed to connect alloying chamber 3 with working gas feed line 1 while third flange allows passage of pulsed laser radiation 8 via translucent window 5 into alloying chamber 3 for sputter of alloying component 7. Note here that alloying component concentration in diamond is adjusted by varying the laser parameters: laser diode pump current, laser pulse frequency and distance from laser radiation focus to alloying component surface. Working gas can be composed of the mix of hydrogen and methane at the ratio of 98:2% to 90:10%. Additionally, oxygen can be added thereto.

EFFECT: precise alloying in the wide range of concentrations (1014 atom/cm3 to 9×1019 atom/cm3) of boron, sulphur and silicon.

3 cl, 1 dwg, 4 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: ions of carbon with opposite charges interact with each other for 20-30 hours at a temperature of 850-950 °C in a high frequency electro-field in the range of frequencies of 40-80 kHz in the presence of iron as a catalyst. The process is carried out in a melt of salts, containing, wt %: SiC - 7.5-11.0; Na2CO3 or K2CO3 - 89.0-92.5. Applied is granulated iron, which has a size of granules 1-3 mm, in a quantity of 5-10% from the melt weight.

EFFECT: invention makes it possible to simplify the process of the diamond synthesis and its instrumentation, eliminate harmful and dangerous conditions.

1 tbl, 1 ex

Pcd diamond // 2522028

FIELD: process engineering.

SUBSTANCE: invention relates to PCD diamond to be used in production of water-jet ejectors, engraving cutters for intaglio, scribers, diamond cutters and scribing rollers. PCD diamond is produced by conversion and sintering of carbon material of graphite-like laminar structure at superhigh pressure of up to 12-25 GPa and 1800-2600°C without addition of sintering additive of catalyst. Note here that sintered diamond grains that make this PCD diamond feature size over 50 nm and less than 2500 nm and purity of 99% or higher. Diamond features grain diameter D90 making (grain mean size plus grain mean size × 0.9) or less and hardness of 100 GPa or higher.

EFFECT: diamond features laminar or fine-layer structure, ruled out uneven wear, decreased abrasion.

15 cl, 5 tbl, 5 ex

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

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: 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

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

FIELD: producing artificial diamonds.

SUBSTANCE: method comprises preparing diamond substrate virtually having no defects, preparing the initial gas, decomposing initial gas to produce the atmosphere for synthesis that nitrogen concentration of which ranges from 0.5 to 500 particles per million, and homogeneous epitaxy growth of diamond on the surface.

EFFECT: increased thickness of diamond.

40 cl, 9 dwg, 5 ex

FIELD: production of diamond layers.

SUBSTANCE: diamond layer at thickness more than 2 mm is obtained through chemical deposition from gaseous phase. Method includes homo-epitaxial growth of diamond layer on surface of backing at low level of defects in atmosphere containing nitrogen at concentration lesser than 300 billion parts of nitrogen.

EFFECT: improved quality of diamond layers.

36 cl, 10 dwg, 1 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing coloured diamond materials, which can be applied as precious stones or cutting instruments. Method includes stages of growing monocrystalline diamond material in accordance with CVD-technology, with diamond material having concentration of single substituting nitrogen atoms [Ns0] less than 1 ppm; initial CVD-diamond material is colourless, or, in case it is not colourless, then, according to colour gradation brown or yellow, and if it is brown according to colour gradation, then it has level G (brown) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and if it is yellow according to colour gradation, it has level T (yellow) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and irradiation of initial CVD-diamond by electrons to introduce isolated vacancies into diamond material in such a way that product of the total concentration of vacancies × way length [Vt]×L, in irradiated diamond material at said stage or after additional processing after irradiation, including annealing irradiated diamond material at temperature at least 300°C and not higher than 600°C, constitutes at least 0.072 ppm cm and not more than 0.36 ppm cm.

EFFECT: diamond material becomes fancy light-blue or fancy light greenish blue in colour.

21 cl, 4 dwg, 3 tbl, 9 ex

Diamond faceting // 2537278

FIELD: process engineering.

SUBSTANCE: invention is intended for use in production of jewellery. Proposed method consists in diamond site shaping to cone with cone generatrix angle to girdle plane. Diamond faceting features the following parameters: diamond diameter D, total height H=0.61D, cone base d=0.52D, girdle depth r=0.04D, top height with girdle h1=0.22D, bottom height to girdle h2,=0.39D, inclination of top faces to girdle plane 23.5°, bottom inclination to girdle plane 38.5°, cone generatrix inclination to girdle - 17°.

EFFECT: perfected diamond dye play.

1 dwg

FIELD: process engineering.

SUBSTANCE: decorative composite body (1) comprises glass body (2) and polymer (3) to cover partially said glass body (2). Portion of glass body surface is located on outer surface of decorative composite body (1). Note here that at least two adjacent areas (8) of glass and polymer material (3) on composite body (1) outer side are ground in as-boded state. Glass body (2) areas verging on polymer material (3) are provided, at least partially, with mirror coat.

EFFECT: ruled out air bubbles and optical defects.

21 cl, 22 dwg

Up!