Plate made from monocrystalline diamond (versions) and method of obtaining it

FIELD: technological process.

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

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

41 cl, 4 ex, 6 dwg

 

The invention relates to single-crystal diamond.

The diamonds have a number of unique properties, including optical transparency, conductivity, hardness, wear resistance and electronic properties. If many of the mechanical properties of diamond inherent diamonds of various types, some of their properties largely depend on the type of diamond. For example, the best properties are obtained by the method of chemical vapour deposition (CVD) single-crystal diamonds, whose properties are often superior to polycrystalline diamond obtained by the method of CVD diamonds, obtained under high pressure/high temperature, and natural diamonds.

In many cases, a significant obstacle to the application of existing diamonds are their limited transverse (lateral) dimensions. Polycrystalline diamond layers obtained by the method of CVD, helped mainly to solve the problem in those applications where it is acceptable to use a polycrystalline structure, but in many areas of technology polycrystalline diamonds are not applicable.

Although natural and obtained under high pressure/high temperature diamonds are not applicable in some areas, they are used as a substrate for growing diamond by the method of HOP is. Although the substrate can have a variety of crystallographic orientation of the substrate with the largest area and the most appropriate orientation, which can be obtained for growing high quality diamond CVD method, is typically a substrate with a main surface lying in the plane (001). When used in the present description crystallographic Miller indices (hkl), which characterize the plane in the system of coordinate axes x, y, z, it is assumed that the z axis runs along the normal to the substrate surface and parallel to the direction of growth. Then the x-axis, y will lie in the plane of the substrate, being from the point of view of symmetry are equivalent to each other, but different from the z-axis as determining the direction of growth of the diamond.

Large natural monocrystalline diamonds are extremely rare and expensive, and the substrate in the form of large plates of natural diamonds, is applicable for growing diamond by the CVD method, did not find applications because of the very high economic risk associated with their manufacture and use. In the lattice of natural diamonds, particularly when used as a substrate of large size, there are often tensions and defects, which leads to twinning and other problems when growing diamond by the CVD method or the formation of cracks in the synthesis process. In addition to the, dislocation common in substrates of natural diamonds, are reproduced in the layer deposited by the CVD method, which also affects their electronic properties.

Synthetic diamonds produced under high pressure/high temperature, also have limitations in size, while their quality is lower than they are larger, and their major disadvantage is the inclusion. The plates of larger size, is made of synthetic diamonds, missing corners, because of what they are side faces lying outside the plane {100}, for example in the planes {110}, or they have inclusions or voltage. In the process of synthesis of additional faces are formed, for example, in the planes {111}, which are located between the upper face in the plane (001) and side faces in the planes {110} (see figure 1). In recent years considerable effort has been directed towards the synthesis under high pressure/high temperature high quality diamonds, is applicable as monochromators, and although some success has been achieved, the size of the resulting high pressure/high temperature plates used as substrates, remains limited.

In particular, it is known that the synthesis of thick layers by a CVD method faces in the planes {111} usually produce twins, which limits the area of growth ideal Monogr the growth and often leads to a deterioration of their properties and even the formation of cracks in the synthesis process, which is further compounded by thermal stress that occurs under the influence of the temperature of cultivation. The formation of twins on the faces in the planes {111} especially prevents the increase of the maximum dimensions of these plates with the main face (surface) in the plane (001), limited side faces in the planes {100}.

Existing conventional substrate with the main line in the plane (001) reach approximately 7 mm (square side), if they are restricted to edges <100>, and about 8.5 mm on the surface of the main faces, if they are restricted to edges <100> and <110>.

Homoepitaxially synthesis of diamond by CVD method provides for epitaxial growing of diamond by CVD method on the existing diamond plate and is described in detail in the literature. Of course, its application is still limited by the availability of existing diamond plates. To obtain the plates of a larger area the focus was also given to their cultivation in the lateral direction, which increased the total area of the extended plate. Similar to the method described in the publication EP 0879904.

Alternative homoepitaxially cultivation is hetero-epitaxial growth, in which the diamond is grown on bipolar non-diamond substrate. However, in all described cases, the result about the ECCA is significantly different from the result obtained homoepitaxial cultivation, and is characterized by the presence of small angle boundaries between having a high degree of orientation, but not exactly oriented areas. Such boundaries seriously degrade the properties of the diamond.

Homoepitaxially the cultivation of diamonds to increase the square plate obtained by the method of CVD is associated with numerous problems.

If it were possible ideal homoepitaxially growing on diamond plate, grown material would have looked mainly as illustrated in figures 1 and 2. Illustrated the morphology of the grown material suggests a lack of growth of competing polycrystalline diamonds. In practice usually takes place competition from polycrystalline material growing on the surface, on which is placed the substrate of the diamond plate. This is illustrated in figure 3.

Figure 3 shows the substrate of the diamond plate 10 placed on the surface 12. As examples of surface material 12 can lead molybdenum, tungsten, silicon and silicon carbide. In the process of growing diamond by the CVD method on the verge 14 in the plane (001) and lateral surfaces 16, two of which are shown in figure 3, the growth of single-crystal diamond. The side surface 16 lie in planes {010}. Grew the diamond will also take place at the corners and the tops 18 of the plate, developing in the outer direction. Growth of diamond on all surfaces will be homoepitaxially with the formation of a monocrystalline structure. Each of the faces of the substrate on which growth occurs, and any of the new surfaces formed during growth is a growth sector. For example, shown in figure 3, the material 24 is rising from the plane {101}, thus forming a growth sector {101}.

With homoepitaxially growth of the single crystal is going to compete with the growth of polycrystalline diamond 20 occurring on the surface 12. Depending on the thickness of the layer of single-crystal diamond obtained on the surface 14, the grown polycrystalline diamond 20 may meet along the line 22, as shown in figure 3, with homoepitaxially grown single-crystal diamond.

From figure 2 one would hope on the possibility of using material grown on the side surfaces of the substrate in a horizontal direction (in hand), for the manufacture of the substrate larger in size, including the material of the source substrate. However, as follows from figure 3, in reality this plate will contain competing polycrystals. The plate obtained parallel to the original substrate, but above it in the accreted layer is likely to be twinning, especially if it is made from a material received in the sector growth of {111}.

When growing diamonds in the absence of competition polycrystalline structures with single-crystal diamond remains an unsolved problem, consisting in the fact that the quality of growing single-crystal diamond in the horizontal direction is generally low, due to the differences in geometry and process conditions of cultivation on the lateral edges of the substrate of the diamond and is further exacerbated by the way that is used to inhibit the growth of polycrystals.

The defects of the substrate used for growing diamond by the CVD method, reproduced grown on the layer. Because the process is homoepitaxially, it is obvious that the newly grown material is reproduced such areas as twins. Besides, there are structures such as dislocations, because linear dislocation, by their nature, cannot simply end in itself, but the probability of annihilation of two oppositely directed linear dislocations is very small. After the beginning of each growing process additional dislocations, mainly in areas of discontinuities in the surface, which may be an etching pits, dust particles, border sector growth, etc. Thus, substrates of single-crystal diamond produced by CVD method, dislocat and represent a special problem, and when a few cycles of cultivation, when grown material is used as the substrate in the next stage, the dislocation density increases significantly.

In the present invention, a method of obtaining a wafer of monocrystalline diamond, namely, that take the diamond substrate (virtually no surface defects)on the surface of the substrate by the method homoepitaxial CVD grown diamond, then this grown diamond is shared across the surface of the substrate, preferably perpendicular to this surface (i.e. at an angle of 90° or close to it), with plates from grown by CVD single crystal diamond, the main surfaces of which are located across the substrate surface.

Homoepitaxially growing diamond by the CVD method on the surface of the substrate preferably by the method described in the publication WO 01/96634. In particular, using this method on the substrate can be grown thick single-crystal diamonds of high purity. Grown by the method of homoepitaxial CVD diamond may have a thickness exceeding 10 mm, preferably 12 mm, and more preferably 15 mm Therefore, proposed in the invention method allows to obtain grown by CVD wafer of monocrystalline diamond, the cat is where at least one linear dimension greater than 10 mm, preferably 12 mm, and more preferably 15 mm in linear dimension is defined as any linear measurement taken between two points located on the main surfaces or near them. In particular, such a linear dimension may be a length of the edge (side surface or edge) of the substrate, the distance from one edge or a point on it to the other ribs or other point on this edge, the size of the axis or other similar size.

In particular, proposed in the invention method allows you to get a rectangular plate of monocrystalline diamond with the main surfaces (faces) in the planes (001), limited lateral surfaces or faces in the planes {100}, at least one linear dimension of which, such as the linear size of the edge <100>, exceeds 10 mm, preferably 12 mm, and more preferably 15 mm

Received proposed in the invention method, the plate of single-crystal diamond grown by CVD method, can then be used as the substrate in the implementation of this method. On the main surface of the plate method homoepitaxial CVD can be grown single-crystal diamonds of great thickness.

Another object of the invention is the plate from grown by CVD single crystal diamond, the main surface is STI which are located on its opposite sides in the planes (001) and limited lateral surfaces in the planes {100} (i.e. plate major surfaces lying in planes {001}), and at least one linear dimension of each main surface is greater than 10 mm In one of the private embodiments of the invention, the plate has the shape of a rectangle, square, parallelogram or similar shape, wherein at least one of its lateral surfaces, preferably both side surfaces have a size greater than 10 mm, preferably 12 mm and more preferably more than 15 mm In the most preferred case, the side surfaces are surfaces or faces in the planes {100}, so that the rib or the face of the plate, the size (or sizes) of which exceeds 10 mm, passes in the direction <100>. In addition, the proposed in the invention method allows you to get the plate of diamond or diamond large size, which can produce such a plate bounded by the side surfaces in the planes {100} and the main surfaces in the planes {001}.

Any dislocations or defects on the surface of the diamond substrate or in the zone of interface with the substrate or on its edges, in the process homoepitaxially growing diamond on a substrate typically extend vertically in the direction of growth of diamond. Thus, if the dividing (cutting) grown diamond to carry out PE pendicular surface, where the diamond was grown on a surface of the partition almost no dislocations emerging from the material to the surface and crossing it, because such dispositions will be held generally parallel to the surface. Thus due to repeated operations proposed in the invention method using a newly received wafer as the substrate can be reduced dislocation density as an additional decrease in the density of dislocations intersecting the main surface of any of the plates cut perpendicular to the substrate. In addition, in some cases it is preferable to use the plate, dislocations which are generally parallel to the main faces, and not perpendicular to them.

In General, the highest quality growing diamond by the CVD method is provided in the vertical sector growth in the plane (001). In addition, because the edges of the substrate can be formed dislocations, usually extending vertically upwards, the material of the highest quality, grown by the CVD method, get in the zone of material bounded by vertical planes extending upward from the edges (side edges) of the substrate. Proposed in the invention method allows to obtain one or more new plates large area entirely from this AOR is s high quality material, minimizing defects inside plate and maximizing the quality of its crystal structure.

By combining various features of the present invention, it is possible to obtain a diamond with a lower dislocation density than the material of the source substrate, while the lower limit of the density of dislocations is limited only by the number of repetitions of the method. In particular, the dislocation density is usually intersect the surface perpendicular to the direction of growth (on the surface density of the dislocation of the resulting method, CVD diamond is usually the most high), with a large area of the plate according to the invention and any layers synthesized on it in the future, may be less than 50/mm2preferably less than 20/mm2more preferably less than 10/mm2most preferably less than 5/mm2. The defect density, the easiest way is determined by the method of visual evaluation after the surface treatment, plasma or chemical etching, optimized for the detection of defects (i.e. showing a plasma etching)by, for example, short-term plasma etching described in the publication WO 01/96634. In addition, in cases where the density of dislocations intersecting the main surface of the plate, is a major factor, the dislocation density in main surface of the plate, manufactured proposed in the invention may be less than 50/mm2preferably less than 20/mm2more preferably less than 10/mm2most preferably less than 5/mm2.

If the substrate is made of natural diamond or synthetic diamond, obtained under high pressure/high temperature, it is generally inadvisable to cut perpendicular to the surface of the substrate plate included material of the source substrate, although it is possible. The presence of the substrate material in such a plate may be expedient, if the substrate is a plate obtained by the method of CVD diamond, which in turn can also be obtained proposed in the invention method.

Below the invention is described in more detail with reference to the accompanying drawings on which is shown:

figure 1 shows a schematic perspective view of the diamond plate on which was perfect homoepitaxially growing diamond

figure 2 is a view in section along the line 2-2 in figure 1,

figure 3 is a view in section of the diamond plates, illustrating the growing single-crystal diamond, polycrystalline diamond,

figure 4 is a view in section of the diamond plate on which was homoepitaxially growing diamond according to one of the options is subramania,

figure 5 is a schematic view of the diamond plate on which the indicated angle αunder which passes the direction of orientation of the dislocation relative to the main surfaces of the diamond plate

figure 6 - schematic view of the diamond plate on which the indicated angle β between the direction of orientation of the dislocation and the normal to the major surfaces of the plate.

Next, with reference to the accompanying drawings described one of the embodiments of the invention. Figure 4 shows the diamond plate 30. Diamond plate 30 is a plate of monocrystalline diamond. Its top face 32 lies in the plane (001), and the side surfaces 34 are faces in the planes {010}. The surface 32 has virtually no defects, particularly defects in the crystal lattice, described in the publication WO 01/96634.

According to the method described in the publication WO 01/96634, growing diamond 36 occurs on the diamond substrate 30. This growth is on the top surface 32 in the vertical direction outward from the corners 38 of the substrate 30 and the outside (side) from the side surfaces 34. Grown diamond will be homoepitaxially, monocrystalline and be of high quality, although in the plane {111} of possible dislocation and twinning, as noted above.

On the surface, on which esena substrate, inevitably there will be a growth of polycrystalline diamond. Depending on the thickness of the growth zone 36 diamond grown polycrystalline diamond can reach the bottom surface 40 of this area.

After the growth zone 36 diamond thickness of the grown diamond and the substrate 30 is divided perpendicular (at an angle of about 90°) the surface 32, as shown by the dotted lines 44. The result is a plate 46 of high quality monocrystalline diamond. In practice, the junction between the source substrate and an area of growing diamond will be indistinguishable from the main mass of the sample. The material of the source substrate may remain as part of the plate 46 or can be removed. Can be obtained several plates, each of which is parallel to the next and perpendicular to the substrate.

The method according to publication WO 01/96634 allows you to get the growth zone 36 diamond depth of more than 10 mm Thus obtained diamond plate 46 will have side surfaces 48 length of 10 mm

Plate 46 may be used as the substrate for carrying out the invention method. Thus, if the length of the side surfaces 48 of the plate 46 exceeds 10 mm, and on the main surface 50 of plate-grown diamond of a thickness exceeding 10 mm, can be obtained plate rectangular, square is whether other similar form, all four lateral surfaces of which have a length of more than 10 mm

As shown in figure 4, the diamond is divided perpendicular to the surface 32. The division can be performed at angles other than normal to the surface 32, with the exception of division in planes parallel to the substrate. If the main face of the substrate lies in the plane (001)wafers obtained at angles other than normal to the substrate, will have major faces lying outside of the plane {100}, for example, in the planes{110}, {113}, {111} or in the planes of higher order.

Division of diamond can be performed in planes passing at right angles to the planes 44 of the cutter, shown in figure 4, with the receiving plate with the main line in the plane {100} or at any other angle to the planes 44 cut with getting plates with the main faces of type {hk0}. To obtain a wafer of monocrystalline diamond may need to trim the edges on which the grown diamond is polycrystalline or has defects.

For professionals it should be obvious that the application of the proposed invention a method is not necessary to use the substrate with the main faces in the planes (001): equally suitable for other substrates, for example, with the main faces in the planes {110}, {113} or even {111}, but in General, when implementing the method, it is preferable to use the substrate with the main line in the plane (001), because the substrate is the easiest method to grow CVD diamond of the highest quality, and location of faces, which are formed when it is growing at such a level, is generally the most acceptable for the manufacture of large plates cut from the grown material.

For this reason, the key plate of the substrate with the main line in the plane (001) is the maximum possible size of the rectangular plate, limited only side faces in the planes {100}. In the growing diamond on a plate is relatively easy to get a plate bounded by the side surfaces or faces in the planes {110}, which is rotated 45°as shown in figure 1, as to a limited extent used or not used at all material sector growth in the planes {111}. The area of this new plate, limited side faces in the planes {110}, at least twice the size of the plate bounded by the faces in the planes {100}, but the original plate, bounded by the faces in the planes {100}, as a rule remains the largest inscribed plate bounded by the faces in the planes {100}, which can be made from it. For this reason, in the present description when specifying the size of a plate of single-crystal diamond with the main line in the plane (001) hour what about the mean size built-in rectangular plate the largest area, limited ribs <100>unless the plate has ribs <100>.

The application of the proposed invention the method allows to obtain a product which was previously impossible to obtain. In particular, the invention allows for the production of Windows large area when to provide restrictive apertures, fasteners, mechanical strength, absence of leakage in the vacuum volume, etc. it is not enough to use a team of construction of the Windows smaller. It is also possible to produce the high-voltage device, a large area which provides protection against arcing around the active region of the device. Proposed in the invention, the material with low density of dislocations can also be used in electronic devices, where the dislocations act as traps charge carriers or short circuit.

The direction of growth of the diamond layer obtained by the method of CVD, in General, can be defined according to the structures existing dislocations. There are several variants of their spatial location.

1. The simplest case is when all the dislocations are parallel and in the direction of growth, which makes this area quite obvious.

2. Another common case is the gradual fan RA is going dislocation relative to the direction of growth, usually with a certain degree of symmetry relative to the growth direction and an angle of less than 20°usually less than 10°, often less than 10° and most often less than 5°to the direction of growth. And in this case, the direction of growth of the diamond is also easily determined by dislocations in a small area of the layer of diamond obtained by the CVD method.

3. Sometimes it happens that the plane of the growth of the diamond is not perpendicular to the local direction of growth, and deviation from this trend in the direction at a small angle. In this case, the dislocation can be shifted in the direction perpendicular to the surface of the substrate in the growth zone, in which they are located. In particular, near the edges, for example, lying in the planes {101} facets on the main face of the growth in the plane {001}, the direction of growth can vary significantly from growth areas in the rest of the "internal"part of a layer. In both cases, the General direction of growth across the substrate can be traced on the dislocation structures, but equally obvious that the material is formed in several growth sectors. In those cases, when the directions of the dislocations play an important role, in General, it is desirable to use a material obtained only from one sector growth.

The direction of dislocation for the purposes of the present description is the direction, which is presumably would be the direction of layer growth according to the analysis of the distribution of dislocations according to the above models. Therefore, the direction of dislocation within a specific sector growth predominantly and preferably is the average direction of the dislocation, defined by using the average vector, with at least 70%, more than 80%, and more often more than 90% of dislocations are in the direction different from the average direction at an angle of 20°more preferably 15°even more preferably 10° and most preferably 5°.

The direction of the dislocation can be determined for example by x-ray topography. Not necessarily will display the individual dislocations, but it is possible to identify bundles of dislocations, usually with intensity, partly proportional to the number of such dislocations in the beam. Then, by obtaining layer-by-layer x-ray images in a plane coincident with the direction of the dislocation, an arithmetic mean or preferably weighted average intensity value of a vector, while topograph taken perpendicular to this direction, different point rather than a linear structure. If you know the original direction of growth plate, it is sufficient starting point to determine the direction of the dislocation.

After determining the direction of the dislocation as described above, it can be classifica owano relative to the main faces of a plate of their single-crystal diamond, grown by the CVD method. As shown in figure 5, the diamond plate 60 has opposite sides of the main faces 62 and 64. It is believed that dislocations, the General direction of which is indicated by the lines 66 are oriented mainly parallel to the main faces 62, 64 of the diamond plates 60, if the direction 66 of the orientation of the dislocation rejected from the plane 68, 70 at least one of the main faces 62, 64 of the plate 60 at an angle α less than 30°preferably less than 20°more preferably less than 15°even more preferably less than 10° and most preferably less than 5°. This orientation of the dislocation is usually achieved if the plate of single-crystal diamond obtained by the CVD method, split almost perpendicular to the substrate, on which was grown on the diamond, especially if the plate is isolated from the resulting method CVD material of the highest quality, located in sector vertical growth in the plane (001).

Dislocations oriented generally parallel to the main faces, find application in the field of optics, where their influence on the fluctuation of the refractive index in the light beam passing through the plate, is in a significant reduction of divergence compared with the case where distributed in the same way, dislocations are predominantly perpendicular to the GLA the major faces. In such cases, it is possible to manufacture the plates of the dimensions in length and width exceed 2 mm, more preferably 3 mm, even more preferably 4 mm, most preferably 5 mm, and even most preferably more than 7 mm, which was made possible by an invention method.

Another area in which it is advantageous to use a plate with dislocations passing generally parallel to the main faces of the plate are devices for high voltage, in which the dislocation is able to create a short circuit in the direction of the applied voltage.

Another application is the use of laser window, in which a beam of parallel dislocations, can increase the local electric field and cause failure. To combat this effect shift the direction of the dislocation relative to the direction of the beam or preferably sets the direction of the dislocation parallel to the main faces of the laser window and, therefore, at right angles to the incident laser beam. Thus, due to the implementation proposed in the invention method, the maximum threshold value of laser destruction.

Another way to classify the direction of the dislocation lies in their orientation relative to the normal to the main faces of the plates is. As shown in Fig.6, the plate 80 on opposite sides has a main face 82 and 84. Direction 86 orientation of the dislocation is deflected from the normal 88 to at least one of the main faces 82 and 84 of the plate, if the angle β between the direction 86 orientation of the dislocation defined as described above, and the normal 88 exceeds 20°more preferably 30°even more preferably 40° and most preferably greater than 50°. This orientation of the dislocation is usually achieved if the plate of single-crystal diamond obtained by the CVD method, to separate at an angle to the surface of the substrate, on which was grown on the diamond. As a variant of the same orientation of the dislocation can be obtained if the plate to separate almost perpendicular to the substrate, on which was grown on the diamond, but in the area where the very plane growth is not parallel to the surface of the source substrate, in particular in the sector of layer growth in the planes {101}, grown on the substrate with the main line in the plane (001).

In some cases, to achieve a significant effect it is enough to divert the direction of the dislocation relative to the normal to at least one of the main faces of the plate. Such requirements when making reference diamonds.

Further, the present invention is additionally illustrated on the trail of the operating examples, not exhaustive possibilities of its implementation.

Example 1

For growing diamond by the CVD method according to the method described in WO 01/96633, made two substrates of synthetic diamond with the main faces in the planes {001}. Then made on diamond substrates were grown by one layer thickness 6, 7 mm. Grown layers were investigated on the subject of a direction of a dislocation, and it was found that more than 90% of dislocations, distinguishable by x-ray topography, were oriented with the deviation from the growth direction is within an angle of 20°and more than 80% at an angle of 10°.

Each layer was cut on one side of the plate, with the main faces of each plate had a size of more than 6×5 mm, and the direction of growth was lying in the planes of the major faces.

Then one of the plates was used as the substrate for the second stage of growth of diamond by CVD method in accordance with the method according to WO 01/96633, to obtain a second layer of a thickness exceeding 4 mm, allowing one to obtain the plate size 4×4 mm, cut so that the direction of growth of diamond coincides with the plane of the main face. Then this layer was examined for the density of the dislocations, which are oriented in the direction of growth, which cut it small face subjected showing plasmamembrane, in the result, it was found that the dislocation density is very low and is about 10/mm2. This makes the material particularly suitable for obtaining samples.

Example 2

A key parameter for use in optics is uniformity and variation properties such as birefringence and refractive index. These properties are exposed to field strain surrounding the dislocation bundles.

For growing diamond by the CVD method according to the method described in WO 01/96633, made two substrates of synthetic diamond with the main faces in the planes {001}. Then made on diamond substrates were grown by a single layer thickness of 4 mm. Grown layers were investigated on the subject of a direction of a dislocation, and it was found that the deviation of the direction of a dislocation from the growth direction is within an angle of 15°. Layers were cut two plates, the main faces of which had a size of more than 4×4 mm, and the direction of growth coincided with the plane of the major faces.

Then named layers were used as substrates in the second stage of cultivation. As shown by x-ray topography grown material (thickness 3.5 mm) had a very low content of dislocations, the dislocation in the newly grown materialproperty perpendicular to the dislocations in the source, grown by CVD layer, which was used as the substrate. Upon completion of the second stage of cultivation samples were applied in the field of optics, where an extremely small scattering and birefringence.

Example 3

For growing diamond by the CVD method according to the method described in WO 01/96633, was used for the substrate of synthetic diamond. Then, this substrate was grown on the layer thickness of 7.4 mm Under the terms of the synthesis of this layer was doped with boron to a concentration of 7×1016[In] atoms/cm3measured in the solid phase. The grown layer was investigated on the subject of a direction of a dislocation, and it was found that the deviation of the direction of a dislocation from the growth direction is within an angle of 25°. From this layer were cut two plates, the main faces of which had a size of more than 4×4 mm, and the direction of growth coincided with the plane of the major faces.

Because these plates had a low density of dislocations that intersect the main faces, in combination with boron doping, they are particularly suitable as substrates for electronic devices, such as diamond field-effect transistor with a structure of metal-semiconductor (MESFET).

Example 4

The method described in the publication WO 01/96633 was made synthetic substrate size 6×6 mm. C the fact on this substrate in several stages were grown diamond, increasing at each stage of about 3 mm At the end of each stage, the layer was surrounded accrued around it a layer of polycrystalline diamond, and this polycrystalline layer is removed by laser trimming, leaving the disk with a diameter of about 25 mm, after which the disk is placed in the notch on the disk of tungsten or other metal so that the point at which the single crystal came out on polycrystalline diamond layer was approximately at the level (up to 0.3 mm) of the upper surface of the tungsten disk.

Using the described techniques were grown layers, the final thickness was in the range 10-18 mm and of which were vertically cut plate with ribs <100>. First the size of the plates on the edge of <100> plane of the plate was 10-16 mm, and the second dimension, perpendicular to the first, was 3-8 mm.

Then such plates were made of a substrate used in the second stage of cultivation, which is also using the above-described technology has been thick layers 10-18 mm. of these layers were vertically cut plate, in which the second dimension from the edge of <100> plane main faces exceeded 10-18 mm while maintaining the first size from the edge of <100> within 10-18 mm, for Example, were made of a plate whose size is measured in mutually perpendicular healthy lifestyles the deposits on ribs < 100>, exceeded 15×12 mm

1. A method of obtaining a wafer of monocrystalline diamond, namely, that on the surface of the diamond substrate by a method homoepitaxial chemical vapour deposition (CVD) grown diamond, then this grown diamond is shared across the surface of the substrate with the receiving plate from grown by CVD single crystal diamond, the main surfaces of which are located across the substrate surface.

2. The method according to claim 1, in which grown by the method of homoepitaxial CVD diamond is divided perpendicular to the substrate surface.

3. The method according to claim 1, in which the thickness is grown by the method of homoepitaxial CVD diamond exceeds about 10 mm

4. The method according to claim 3, in which the thickness is grown by the method of homoepitaxial CVD diamond exceeds approximately 12 mm

5. The method according to claim 4, in which the thickness is grown by the method of homoepitaxial CVD diamond exceeds about 15 mm.

6. The method according to any one of claims 1 to 5, in which at least one linear dimension of the plate from grown by CVD single crystal diamond exceed 10 mm

7. The method according to any one of claims 1 to 5, in which the diamond substrate is a plate made from grown by CVD single crystal diamond obtained by the method according to any one of claims 1 to 5.

8. The method according to any of the C claims 1 to 5, in which any original substrate remaining in the film grown by CVD single crystal diamond, removed.

9. The method according to any one of claims 1 to 5, in which the plate grown by CVD single crystal diamond has a shape of rectangle, square, parallelogram or a similar form.

10. Plate of single-crystal diamond grown by chemical vapour deposition (CVD), the major surfaces of which are located on its opposite sides in the planes (001) and limited lateral surfaces in the planes {100}, and at least one linear dimension of each main surface is greater than 10 mm

11. Plate of claim 10 in which at least one linear dimension exceeds 12 mm

12. Plate according to claim 11, in which at least one linear dimension exceeding 15 mm

13. Plate of claim 10, in which the first and second linear dimensions exceeding 10 mm

14. Plate according to item 13, in which the first and/or second linear dimensions exceed 12 mm

15. Plate on 14, in which the first and/or second linear dimensions exceed 15 mm.

16. Plate of claim 10, which represents a rectangular plate, which has at least one linear size of the main surface is the size of the axis, the transverse size or the size of the lateral edges.

17. Plate of claim 10, near to the Torah, at least one linear size of the main surface is the size of the ribs <100>, formed by the intersection of the side surface in the plane of {100} to the main surface.

18. Plate according to item 13, in which the first and second linear dimensions are mutually perpendicular edges <100>, formed by the intersection of the respective side surfaces in the planes {100} with the main surface.

19. Plate according to any one of p-18, which has the shape of a rectangle, square, parallelogram or a similar form.

20. Plate of single-crystal diamond grown by chemical vapour deposition (CVD), the major surfaces of which are located on its opposite sides and intersect existing dislocations, the density of crossing the main surface of dislocations is less than 50/mm2.

21. Plate according to claim 20, in which the density of crossing the main surface of dislocations does not exceed 20/mm2.

22. Plate according to item 21, in which the density of crossing the main surface of dislocations does not exceed 10/mm2.

23. Plate according to item 22, in which the density of crossing the main surface of dislocations does not exceed 5/mm2.

24. Plate according to any one of p-23, in which the density of dislocations intersecting any other plane, does not exceed sootvetstvuyuschego limit values of the dislocation density, crossing the main surface.

25. Plate according to any one of p-23, which has at least one linear dimension greater than 10 mm

26. Plate of single-crystal diamond grown by chemical vapour deposition (CVD), the major surfaces of which are located on its opposite sides and in which dislocations are formed during the growth of diamond, and these dislocations are oriented in a direction that is generally parallel to at least one of the main surfaces.

27. Plate on p, in which the direction of dislocations positioned relative to at least one of the main surfaces at an angle lower than 30°.

28. Plate according to item 27, in which the direction of dislocations positioned relative to at least one of the main surfaces at an angle lower than 20°.

29. Plate on p, in which the direction of dislocations positioned relative to at least one of the main surfaces at an angle lower than 10°.

30. Plate on clause 29, in which the direction of dislocations positioned relative to at least one of the main surfaces at an angle lower than 5°.

31. Plate on p, in which each main surface has a first linear dimension, in the direction corresponding to the General direction of the dislocations, and previews is 2 mm.

32. Plate on p, in which the first linear dimension greater than 3 mm

33. Plate on p, in which the first linear dimension greater than 4 mm.

34. Plate on p, in which the first linear dimension exceeds 5 mm

35. Plate on clause 34, in which the first linear dimension exceeds 7 mm

36. Plate according to any one of p-35, in which each main surface has a second linear dimension perpendicular to the first linear dimension and equal to or greater than his.

37. Plate of single-crystal diamond grown by chemical vapour deposition (CVD), the major surfaces of which are located on its opposite sides, and in which dislocations are formed during the growth of diamond, and the average direction of orientation of these dislocations is deflected from the normal, at least to one of the main surfaces of the plate.

38. Plate on clause 37, in which the average direction of orientation of the dislocations is deflected from the normal, at least to one of the main surfaces of the plate at an angle exceeding 20°.

39. Plate on § 38, in which the average direction of orientation of the dislocations is deflected from the normal, at least to one of the main surfaces of the plate at an angle exceeding 30°.

40. Plate on § 39, in which the average direction of orientation of the dislocation rejected from the norm and, at least one of main surfaces of the plate at an angle exceeding 40°.

41. Plate on p in which the average direction of orientation of the dislocations is deflected from the normal, at least to one of the main surfaces of the plate at an angle exceeding 50°.



 

Same patents:

Coloured diamonds // 2328563

FIELD: technological process.

SUBSTANCE: invention is related to the field of coloured diamonds preparation, which are used, for instance, in decorative purposes. Method of coloured single crystal diamond transformation into different colour includes stages, at which coloured single crystal diamond is prepared by method of chemical depositing from steam phase (CDSP) and prepared diamond is thermally treated at temperature from 1200 to 2500°C and pressure that stabilises diamond, or in inert or stabilising atmosphere. Prepared single crystal may be shaped as thick layer or fragment of layer, which is cut as precious stone.

EFFECT: allows to prepare diamonds with wide range of colour gamma.

61 cl, 8 ex, 5 dwg

FIELD: technological process.

SUBSTANCE: invention is related to growing of garnets single crystals and may be used in laser equipment, magnet microelectronics (semi-conductors, ferroelectrics) and for jewelry purposes. Single crystals of terbium-gallium garnet are prepared by Chochralski method by means of melting primary stock, which includes clarifying calcium-containing additive, and further growing of single crystal from melt to primer. As primary stock mixture of terbium and gallium oxides is used, as calcium containing additive - calcium oxide or carbonate, and after growing crystal is annealed in atmosphere of hydrogen at temperature of 850-950°C for around 5 hours until orange paint disappears.

EFFECT: allows to prepare optically transparent homogeneous crystals.

2 ex

FIELD: carbon materials.

SUBSTANCE: monocrystalline diamond grown via chemical precipitation from gas phase induced by microwave plasma is subjected to annealing at pressures above 4.0 GPa and heating to temperature above 1500°C. Thus obtained diamonds exhibit hardness higher than 120 GPa and crack growth resistance 6-10 Mpa n1/2.

EFFECT: increased hardness of diamond product.

12 cl, 3 dwg, 5 ex

FIELD: microelectronics, namely processes for preparing even-atom surfaces of semiconductors.

SUBSTANCE: method comprises steps of chemical-dynamic polishing of substrate surface in polishing etching agent containing sulfuric acid, hydrogen peroxide and water for 8 - 10 min; removing layer of natural oxide in aqueous solution of hydrochloric acid until achieving hydrophobic properties of purified surface of substrate; washing it in deionized water and drying in centrifuge. Then substrate is treated in vapor of selenium in chamber of quasi-closed volume while forming gallium selenide layer at temperature of substrate Ts = (310 -350)°C, temperature of chamber walls Tc = (230 - 250)°C, temperature of selenium Tsel = (280 - 300)°C for 3 - 10 min. After such procedure substrate is again placed in aqueous solution of hydrochloric acid in order to etch layer of gallium selenide. Invention allows produce even-atom surface of gallium arsenide at non-uniformity degree such as 3Å.

EFFECT: possibility for using substrates for constructing nano-objects with the aid of self-organization effects.

4 dwg

FIELD: microelectronics, namely processes for preparing even-atom surfaces of semiconductors.

SUBSTANCE: method comprises steps of chemical-dynamic polishing of substrate surface in polishing etching agent containing sulfuric acid, hydrogen peroxide and water for 8 - 10 min; removing layer of natural oxide in aqueous solution of hydrochloric acid until achieving hydrophobic properties of purified surface of substrate; washing it in deionized water and drying in centrifuge. Then substrate is treated in vapor of selenium in chamber of quasi-closed volume while forming gallium selenide layer at temperature of substrate Ts = (310 -350)°C, temperature of chamber walls Tc = (230 - 250)°C, temperature of selenium Tsel = (280 - 300)°C for 3 - 10 min. After such procedure substrate is again placed in aqueous solution of hydrochloric acid in order to etch layer of gallium selenide. Invention allows produce even-atom surface of gallium arsenide at non-uniformity degree such as 3Å.

EFFECT: possibility for using substrates for constructing nano-objects with the aid of self-organization effects.

4 dwg

FIELD: chemical industry; other industries; methods of polishing of the silver chloride crystals.

SUBSTANCE: the invention is pertaining to the field of manufacture of the optical elements and may be used in the infrared engineering. The method provides for the abrasive polishing of AgCl crystals with the sodium thiosulfate water solution and with the finishing washing of the treated article in 30-40 % solution of 2-methyl-2-aminopropane (СН3)3CNH2 in ethanol С2Н5ОН and the following dry final polishing. The method ensures the high-accuracy polishing of the articles made out of the silver chloride crystals and the high quality of the polished surfaces.

EFFECT: the invention ensures the high-accuracy polishing of the articles made out of the silver chloride crystals and the high quality of the polished surfaces.

2 ex

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

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

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

3 cl, 1 ex, 1 tbl, 3 dwg

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

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

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

5 cl, 1 ex

FIELD: medical engineering.

SUBSTANCE: method involves machining a billet giving it shape and sharpening the cutting part. Ruby monocrystal boules are used as raw material of the billet, grown up in crystallographic direction of [1011]. They are split into half-boules in [1120] direction, and then cutting into plates. Cutting is carried out in direction set in perpendicular to half-boule crystallographic axes. Before sharpening tool cutting part shaped as cutter, hydrothermal ruby monocrystal plates etching is carried out, to determine tool cutter cut-off directions in crystallographic directions of [1210], [1011] and [0111].

EFFECT: high precision cutting tool possessing increased strength and usable in eye microsurgery.

3 dwg

FIELD: jewelry industry; optics.

SUBSTANCE: proposed method is used for coloring fianites (man-made diamonds) in green, blue and brownish-yellow colors; proposed method may be also used in optics for production of colored light filters withstanding temperatures above 1000°C. Proposed method includes preliminary application of cobalt on fianite surface to be colored and at least one metal whose oxide is liable to spinelle-forming with oxide of bivalent cobalt, iron and/or aluminum, for example. Then material is subjected to heat treatment in oxygen-containing atmosphere at temperature above 1000°C but not exceeding the fianite melting point. The procedure is continued for no less than 3 h. Coat is applied by thermal spraying of metals in vacuum. Said metals may be applied in turn and simultaneously. For obtaining bluish-green color of fianite, cobalt and aluminum are applied at atomic ratio of 1:1 to 1:2. For obtaining yellowish-green color, cobalt, aluminum and iron are applied at atomic ratio of 1:1 :0.1-0.2. For obtaining yellowish-brown color, cobalt and iron are applied at ratio of 1:1 to 1:2.

EFFECT: enhanced resistance to high temperature and chemical action.

7 cl, 11 ex

FIELD: technological process.

SUBSTANCE: invention pertains to the technology of obtaining monocrystalline diamond material and can be used in optics for making optical and laser windows, optical reflectors and refractors, diffraction grating and calibration devices. The diamond material is obtained using chemical vapour deposition method (CVDM) in the presence of a controlled nitrogen level, which allows for controlling development of crystal defects and therefore obtain diamond material with basic characteristics, necessary for use in optics.

EFFECT: material with basic characteristics, necessary for use in optics.

75 cl, 8 tbl, 15 ex, 9 dwg

Coloured diamonds // 2328563

FIELD: technological process.

SUBSTANCE: invention is related to the field of coloured diamonds preparation, which are used, for instance, in decorative purposes. Method of coloured single crystal diamond transformation into different colour includes stages, at which coloured single crystal diamond is prepared by method of chemical depositing from steam phase (CDSP) and prepared diamond is thermally treated at temperature from 1200 to 2500°C and pressure that stabilises diamond, or in inert or stabilising atmosphere. Prepared single crystal may be shaped as thick layer or fragment of layer, which is cut as precious stone.

EFFECT: allows to prepare diamonds with wide range of colour gamma.

61 cl, 8 ex, 5 dwg

FIELD: chemistry.

SUBSTANCE: process of hard monocrystalline diamond preparation compises fixing of inoculating diamond in the holder and its growing by the way of chemical deposition from gaseous phase induced by microwave plasma. The process is implemented at temperature ca 1000°C - 1100°C in medium N2/CH4=0.2-5.0 and CH4/H2=12-20% at total pressure 120-220 torr. Derived monocrystalline diamond has the hardness in the range 50-90GPa and fracture strength 11-20MPa m1/2.

EFFECT: increasing of diamond hardness.

7 cl, 4 dwg

FIELD: carbon materials.

SUBSTANCE: monocrystalline diamond grown via chemical precipitation from gas phase induced by microwave plasma is subjected to annealing at pressures above 4.0 GPa and heating to temperature above 1500°C. Thus obtained diamonds exhibit hardness higher than 120 GPa and crack growth resistance 6-10 Mpa n1/2.

EFFECT: increased hardness of diamond product.

12 cl, 3 dwg, 5 ex

FIELD: crystal growth.

SUBSTANCE: method comprises separating the inoculation from the source of carbon by a metal-dissolver made of an alloy of ferrous, aluminum, and carbon when a 20-30°C temperature gradient is produced between the carbon source and inoculation. The growth zone is heated up to a temperature higher than the melting temperature of the alloy by 10-20°C, and the melt is allowed to stand at this temperature for 20 hours. The temperature then suddenly increases above the initial temperature by 10-25°C and decreases down to the initial value with a rate of 0.2-3 degree per minute.

EFFECT: improved quality of crystal.

1 tbl, 2 ex

FIELD: inorganic chemistry; mining industry; electronics; other industries; methods of the synthesis of the needle-shaped and lengthened diamonds.

SUBSTANCE: the invention is pertaining to the field of the inorganic chemistry, in particular, to the method of production of the needle shape synthetic diamonds and may be used in the industrial production of the special-purpose diamonds, for example, for manufacture of the boring crown bits and the dressers, and also in the capacity of the blocks details of the audio-video playback equipment, for manufacture of the feeler probes, in the micro-mechanical devices etc. The method provides for commixing of the fusion charge composed of the alloy of Mn-Ni-Fe in the mass ratio of 60±5÷30±5÷10±5 and the powder of the carbon-containing substance and treatment of the mixture at the pressure exceeding 40 kbar and the temperature over 950°С at heating rate less than 100°C/minutes. In the capacity of the carbon-containing substance use the needle-shaped coke or graphite on the coke basis with the single-component anisotropic structure with the degree of graphitization of no less than 0.55 relative units. The invention allows to simplify the production process of the synthesis of the needle-shaped and lengthened diamonds and to increase the percentage of their output within one cycle of the production process.

EFFECT: the invention ensures simplification of the production process of the synthesis of the needle-shaped and lengthened diamonds, the increased percentage of their output within one cycle of the production process.

2 ex, 2 dwg

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: carbon particles.

SUBSTANCE: invention relates to technology of preparing particles having monocrystalline diamond structure via growing from vapor phase under plasma conditions. Method comprises step ensuring functioning of plasma chamber containing chemically active gas and at least one carbon compound and formation of reactive plasma, which initiate appearance of seed particles in the plasma chamber. These particles ensure multidirectional growing of diamond-structured carbon thereon so that particles containing growing diamond are formed. Functioning of plasma chamber proceeds under imponderability conditions but can also proceed under gravitation conditions. In latter case, seed particles and/or diamond-containing particles in reactive plasma are supported under effect of external gravitation-compensating forces, in particular by thermophoretic and/or optic forces. Temperature of electrons in the plasma are lowered by effecting control within the range from 0.09 to 3 ev. Chamber incorporates plasma generator to generate plasma with reduced electron temperature and device for controlling forces to compensate gravitation and to allow particles to levitate in the plasma with reduced electron temperature. This device comprises at least one levitation electrode for thermophoretic levitation of particles in plasma with reduced electron temperature or an optical forceps device.

EFFECT: enabled efficient growing of high-purity duly shaped particles with monocrystalline diamond structure having sizes from 50 μm to cm range (for instance, 3 cm).

19 cl, 5 dwg

FIELD: production of synthetic diamonds, which may be used as windows in high power lasers or as anvils in high pressure devices.

SUBSTANCE: device for forming a diamond in precipitation chamber contains heat-draining holder for holding a diamond and ensuring thermal contact with side surface of diamond, adjacent to the side of growth surface of diamond, non-contact temperature measurement device, positioned with possible measurement of diamond temperature from edge to edge of growth surface of diamond, and main device for controlling technological process for producing temperature measurement from non-contact device for measuring temperature and controlling temperature of growth surface in such a way, that all temperature gradients from edge to edge of growth surface are less than 20°C. A structure of sample holder for forming a diamond is also included. Method for forming a diamond includes placing a diamond in the holder in such a way, that thermal contact is realized with side surface of diamond, adjacent to growth surface side of diamond, measurement of temperature of growth surface of diamond, with the goal of realization of temperature measurements, control of growth surface temperature on basis of temperature measurements and growth of monocrystalline diamond by means of microwave plasma chemical precipitation from steam phase on growth surface, under which the speed of diamond growth exceeds 1 micrometer per hour.

EFFECT: possible production of sufficiently large high quality monocrystalline diamond with high growth speed.

7 cl, 1 tbl, 7 dwg

FIELD: technological process.

SUBSTANCE: invention pertains to the technology of obtaining monocrystalline diamond material and can be used in optics for making optical and laser windows, optical reflectors and refractors, diffraction grating and calibration devices. The diamond material is obtained using chemical vapour deposition method (CVDM) in the presence of a controlled nitrogen level, which allows for controlling development of crystal defects and therefore obtain diamond material with basic characteristics, necessary for use in optics.

EFFECT: material with basic characteristics, necessary for use in optics.

75 cl, 8 tbl, 15 ex, 9 dwg

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