JP3738647B2 - Silicon carbide single crystal manufacturing method and single crystal manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a silicon carbide (SiC) single crystal that can be used for materials such as semiconductors and light-emitting diodes.
[0002]
[Prior art]
Conventional silicon carbide single crystal is produced by arranging a seed crystal above a container (graphite crucible) and a silicon carbide raw material part below the container as disclosed in JP-A-8-295595. The silicon carbide single crystal is grown on the seed crystal by the silicon carbide sublimation gas supplied from the silicon carbide raw material portion by keeping the seed crystal at a lower temperature than the silicon carbide raw material portion.
[0003]
[Problems to be solved by the invention]
When the silicon carbide single crystal is grown as described above, the silicon carbide single crystal grows in a tapered shape whose diameter increases with the growth.
[0004]
However, the bulk shape is different from the shape that is ultimately desired for use as a wafer, and the shape must be appropriately changed to the shape that is desired to be used. However, the silicon carbide single crystal is very hard and the shape change is not easy. There is.
[0005]
In addition, in the case of ideal crystal growth, that is, in the state where the shape of the seed crystal is maintained or the shape of the seed crystal is similar and the growth surface is kept flat, it grows in a columnar shape. And a good silicon carbide single crystal can be obtained.
[0006]
However, in the case of normal crystal growth, the growth rate differs between the center and the periphery of the growth surface. As a result, the center of the grown silicon carbide single crystal ingot becomes convex (mushroom type) or the center becomes concave. For this reason, there exists a problem that a crystal defect, especially a crack defect generate | occur | produces in the grown silicon carbide single crystal.
[0007]
Here, let us consider the mechanism of crack defect generation. In addition, when the growth surface of the silicon carbide single crystal to be grown is uneven, the circular cross section thereof is in a curved surface state. Therefore, assuming a circular model as shown in FIG. Explain the mechanism.
[0008]
When the silicon carbide single crystal grows, the <112-0> direction is slower than the <11-00> direction. This is because atoms for growing the (11-00) plane are easily arranged.
[0009]
For this reason, assuming that crystal growth is performed in a large free space, the crystal protrudes in the <112-0> direction as shown in FIG. It becomes a hexagon.
[0010]
At this time, as shown in FIG. 13B, atoms (arrow S) running on the (11-00) plane collide with each other due to defects or some lattice mismatch, and a crack nucleus is present at the collision position (arrow T). Will occur. Starting from this nucleus, a crack defect extending in the <11-00> direction or the <112-0> direction as shown by the arrow U in FIG.
[0011]
The present invention has been made in view of the above problems, and a first object thereof is to enable a silicon carbide single crystal to be finally formed in a shape that is desired to be used as a wafer.
[0012]
It is a second object of the present invention to suppress the generation of crack nuclei that cause crack defects.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, in the invention described in claim 1, in the vicinity of the silicon carbide single crystal substrate (3), the wall member (7, 7a, 7b) surrounds the outer periphery of the silicon carbide single crystal substrate. And the growth of the silicon carbide single crystal (10) in the direction of the wall member is controlled by causing the wall member to have a temperature higher than the sublimation temperature of silicon carbide when the silicon carbide single crystal is grown. It is characterized by that.
[0014]
Thus, by surrounding the outer periphery of the silicon carbide single crystal substrate in the vicinity of the silicon carbide single crystal substrate, the growth in the radial direction of the silicon carbide single crystal can be controlled by the high-temperature wall member. Thereby, the shape of the outer periphery of the silicon carbide single crystal can be arbitrarily controlled.
[0015]
  And the wallThe member is equipped with a hollow partCircleIf the cylindrical hollow portion has a diameter larger than that of the silicon carbide single crystal substrate, and the silicon carbide single crystal substrate is disposed in the hollow cylindrical portion,,CircleSilicon carbide single crystal can be formed in a cylindrical shape,CircleIf the cross-sectional shape of the cylindrical wall member is an arc shape corresponding to the orientation flat, a silicon carbide single crystal in which the orientation flat is formed can be obtained.
[0016]
  Claims3As shown, the wall member is provided with a hollow partTakuroComposed of prismatic shape,The sixIf a silicon carbide single crystal substrate is placed in a hollow part of a prismatic shape, SixA prismatic silicon carbide single crystal can be obtained.
[0017]
  Claims2And claims4As shown in FIG. 4, if the <112-0> direction or the <11-00> direction of the silicon carbide single crystal substrate is aligned with the shape of the wall member, for example, It can be set as a silicon carbide single crystal.
[0018]
  And claims5As shown in FIG. 5, when the wall member is formed in a cone shape whose radial direction expands as the silicon carbide single crystal grows, the size of the diameter can be controlled while increasing the diameter.
[0019]
  And the wallThe member has a cross-sectional shape in the vicinity of the silicon carbide single crystal substrate.Is a circleWhen the silicon carbide single crystal substrate is formed in a cone shape whose cross-sectional shape changes to a hexagon as the silicon carbide single crystal substrate grows, it can be shaped according to the growth of the silicon carbide single crystal.
[0020]
  Claims6As shown, the wall member is formed on the surface of the silicon carbide single crystal substrate.LawWhat is necessary is just to make it the cone shape inclined 5 to 80 degree | times with respect to the line direction.
[0021]
  Claims7As shown in FIG. 3, if the distance between the wall member and the silicon carbide single crystal substrate is within 5 to 30% of the radius of the silicon carbide single crystal substrate, the radial direction of the silicon carbide single crystal is caused by the heat of the wall member. Growth can be suppressed.
[0022]
  Claims8 or 9A silicon carbide single crystal manufacturing method can be carried out using the silicon carbide single crystal manufacturing apparatus shown in FIG.
[0023]
  Claim10In the invention described in the above, by disposing a silicon carbide single crystal substrate (3) to be a seed crystal in the containers (1, 2), and supplying a silicon carbide raw material sublimation gas to the silicon carbide single crystal substrate, In a method for manufacturing a silicon carbide single crystal in which a silicon carbide single crystal (10) is grown on a silicon carbide single crystal substrate, wall members (7, 7a) having a hexagonal hollow portion so as to surround the outer periphery of the silicon carbide single crystal substrate 7b), and the silicon carbide single crystal to be grown passes through the hollow portion of the wall member.
[0024]
Thus, by allowing the silicon carbide single crystal to be grown to pass through the hollow portion of the wall member, an ideal hexagonal columnar silicon carbide single crystal ingot having a flat growth surface can be formed. For this reason, generation of crack nuclei, which is a cause of generation of crack defects, can be suppressed.
[0025]
  Claim12The invention described in 1 is characterized in that a minute gap is provided between the wall member and the silicon carbide single crystal.
[0026]
Thereby, the silicon carbide single crystal can be easily taken out from the wall member.
[0027]
  Claim13The silicon carbide single crystal substrate is arranged so that the mold surface {11-00} surface of the silicon carbide single crystal and the hexagonal inner wall surface of the wall member coincide with each other.
[0028]
  Thereby, generation | occurrence | production of the crack by the atom collision in the growth surface of a silicon carbide single crystal can be suppressed. In this way, for example, the claim18As shown in FIG. 3, even when the size of the silicon carbide single crystal substrate is smaller than the size of the hollow portion of the wall member, the generation of cracks due to atomic collisions within the growth surface of the silicon carbide single crystal can be suppressed.
[0029]
  Claim14In the invention described in (1), the shape of the silicon carbide single crystal substrate is a hexagon formed of a mold surface {11-00} plane.
[0030]
Thereby, the shape of the seed crystal is inherited by the silicon carbide single crystal, and generation of crack nuclei can be suppressed from the initial stage of growth.
[0031]
  Claim15In the invention described in (1), the length in the growth direction of the silicon carbide single crystal in the wall member is made longer than the silicon carbide single crystal to be grown, and the silicon carbide single crystal grows along the inner wall of the wall member. It is characterized by doing so.
[0032]
Thereby, it can be made to grow along an inner wall surface of a guide, and the growth that a growth surface becomes flat can be performed.
[0033]
  Claim16In the invention described in (1), the length in the growth direction of the silicon carbide single crystal of the wall member is made shorter than the silicon carbide single crystal to be grown, and after the silicon carbide single crystal grows longer than the wall member. In addition, the silicon carbide single crystal is composed of the mold surface {11-00} plane.RurokuIt is characterized by growing in a square shape.
[0034]
  Thus, when the length in the growth direction of the silicon carbide single crystal in the wall member is shorter than the silicon carbide single crystal to be grown, the growth that has passed through the wall member as the silicon carbide single crystal grows. A sufficiently free space for the crystal expands, but the grown crystal once formed into an ideal shape by the wall member is composed of the intact {11-00} plane.RurokuGrows with a square shape. Therefore, an ideal hexagonal columnar silicon carbide single crystal ingot having a flat growth surface can be formed, and the generation of crack nuclei that can cause crack defects can be suppressed.
[0035]
  Claim17In the invention described in the above, the size of the hollow portion of the wall member is made smaller than the size of the silicon carbide single crystal substrate, and the wall member is arranged in front of the silicon carbide single crystal substrate in the growth direction of the silicon carbide single crystal substrate. After the silicon carbide single crystal grows and reaches the wall member, the silicon carbide single crystal grows along the inner wall surface of the wall member.
[0036]
  Even in this case, the grown crystal once formed into an ideal shape by the wall member is composed of {11-00} planes.RurokuSince it grows while maintaining the square shape, the generation of crack nuclei, which is the cause of crack defects, can be suppressed.
[0037]
  Claim19In the invention described in (1), the silicon carbide single crystal substrate is arranged on a pedestal provided in the container, and the shape of the pedestal is a hexagon.
[0038]
Thus, the temperature of a seed crystal can be kept uniform by making the shape of a base into a hexagon.
[0039]
  Claim20The silicon carbide single crystal substrate having a hexagonal shape has all sides larger than the sides of the hexagonal pedestal, and the surface of the pedestal on which the silicon carbide single crystal substrate is disposed is silicon carbide. The entire surface is covered with a single crystal substrate.
[0040]
If each side of the silicon carbide single crystal substrate serving as the seed crystal is made larger than each side of the pedestal, the portion protruding from the pedestal becomes high temperature and is sublimated during growth by thermal etching. By this thermal etching, crystal defects at the outer edge portion of the silicon carbide single crystal substrate are removed, and the nucleus of crack generation can be removed.
[0041]
  Claim21In the invention described in item 1, the inner wall surface of the wall member has a structure inclined with respect to the growth direction of the silicon carbide single crystal.
[0042]
Thereby, the silicon carbide single crystal to be grown can be controlled to expand in the radial direction, or can be controlled to be narrowed in the radial direction.
[0043]
  Claim22In the invention described in (1), the size of the hollow portion of the wall member is a structure that expands with respect to the growth direction of the silicon carbide single crystal.
[0044]
Thus, it is good also as a structure which expands the size of the hollow part of a wall member with respect to the growth direction of a silicon carbide single crystal. Even in this case, if the silicon carbide single crystal is expanded so as to be prevented from expanding in the radial direction, crystal defects can be prevented from being formed at the outer edge of the silicon carbide single crystal.
[0045]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1A shows a graphite crucible as a crystal growth apparatus used in the first embodiment of the present invention. In this graphite crucible, a silicon carbide single crystal 10 is grown on a silicon carbide single crystal substrate 3 which is a seed crystal by sublimating the silicon carbide raw material powder 4 provided at the bottom of the graphite crucible by heat treatment. .
[0046]
This graphite crucible includes a substantially cylindrical crucible body 1 having an open top surface and a lid member 2 that closes the opening of the crucible body 1. A silicon carbide single crystal substrate 3 is arranged on the pedestal using the lid 2 constituting the graphite crucible as a pedestal. The bottom portion of the crucible body 1 is filled with silicon carbide raw material powder 4. By sublimating the silicon carbide raw material powder 4, silicon carbide single crystal substrate 3 is used as a seed crystal, and silicon carbide is formed on the surface of the seed crystal. A single crystal can be grown.
[0047]
Further, the lid 2 of the graphite crucible is provided with a guide 7 as a wall member. FIG. 1B shows a cross-sectional view taken along the line AA in FIG.
[0048]
As shown in FIGS. 1A and 1B, the guide 7 has a substantially regular hexagonal column having a hollow shape surrounding the outer periphery of the silicon carbide single crystal substrate 3 serving as a seed crystal. It consists of The silicon carbide single crystal substrate 3 is aligned so that each corner of the substantially regular hexagonal column coincides with the plane orientation of the silicon carbide single crystal substrate 3. For example, the diagonal line passing through the center of the hexagon and the silicon carbide single crystal The crystal substrate 3 is aligned so as to coincide with the <112-0> direction or the <11-00> direction. Specifically, since the plane orientation and in-plane direction of the silicon carbide single crystal substrate 3 can be accurately measured by Laue imaging using X-rays or the like, before the silicon carbide single crystal substrate 3 is attached to the lid member 2. The in-plane orientation is measured, and thereafter, the orientation is matched with the shape direction of the guide 7, and the silicon carbide single crystal substrate 3 is attached to the lid member 2. Thereby, the direction can be adjusted with high accuracy.
[0049]
The distance between the sides of the substantially regular hexagonal column facing each other is slightly longer than the length of the diameter of the seed crystal. For example, when the silicon carbide single crystal is grown, the distance is set such that the seed crystal can be prevented from spreading in the radial direction depending on the temperature of the guide 7. Thus, the guide 7 is arranged in the vicinity of the silicon carbide single crystal substrate 3.
[0050]
Although not shown, the graphite crucible can be heated by a heater in a vacuum vessel into which argon gas can be introduced, and the silicon carbide single crystal substrate 3 as a seed crystal is adjusted by adjusting the power of the heater. Can be maintained at a temperature lower by about 100 ° C. than the temperature of the silicon carbide raw material powder 4.
[0051]
A manufacturing process of a silicon carbide single crystal using the thus configured crystal growth apparatus will be described.
[0052]
First, the temperature of the silicon carbide raw material powder 4 is heated to 2000-2500 degreeC. Then, a temperature gradient is provided in the graphite crucible so that the temperature of silicon carbide single crystal substrate 3 is lower than the temperature of silicon carbide raw material powder 4 by adjusting the heater or the like.
[0053]
Next, when the pressure in the graphite crucible is set to 13.3 Pa to 6.65 kPa (0.1 to 50 Torr) and the sublimation growth is started, the silicon carbide powder 4 is sublimated to become a sublimation gas, and the silicon carbide single crystal substrate 3, silicon carbide single crystal 10 grows on the surface of silicon carbide single crystal substrate 3 which is at a relatively lower temperature than silicon carbide powder 4 side.
[0054]
At that time, the guide 7 is disposed in the vicinity of the silicon carbide single crystal substrate 3, and the guide 7 is heated by the temperature transmitted from the graphite crucible, so that the silicon carbide grown on the silicon carbide single crystal substrate 3 is grown. The single crystal 10 receives the temperature of the guide 7 and the growth is suppressed in the direction in which the diameter increases.
[0055]
Thus, by arranging guide 7 so as to surround the vicinity of silicon carbide single crystal substrate 3, silicon carbide single crystal 10 can be formed in a substantially hexagonal columnar shape. Thereby, the shape of silicon carbide single crystal 10 can be arbitrarily changed, and silicon carbide single crystal 10 can be grown in a shape used as a final wafer.
(Second Embodiment)
FIG. 2A shows the overall configuration of the crystal manufacturing apparatus in the present embodiment. FIG. 2B is a cross-sectional view taken along the line BB in FIG. In addition, since the crystal manufacturing apparatus of this embodiment has the structure substantially the same as 1st Embodiment, only a different part is demonstrated.
[0056]
In the present embodiment, as shown in FIG. 2B, the shape of the guide is changed with respect to the first embodiment. Specifically, in the present embodiment, the guide is formed in a substantially cylindrical shape, and a part of the cylindrical shape is formed in an arc shape, that is, the hollow part of the guide is formed by cutting out a part of the columnar shape. Yes. As described above, the hollow portion of the guide is formed in the shape of the semiconductor substrate on which the orientation flat is formed. The silicon carbide single crystal substrate 3 is aligned so that the notch and the plane orientation of the silicon carbide single crystal substrate 3 coincide with each other. For example, the center of the columnar shape and the line passing through the center of the notch are carbonized. The silicon single crystal substrate 3 is aligned so that the <112-0> direction or the <11-00> direction coincides.
[0057]
Further, the inner diameter of the guide is slightly larger than the diameter of the seed crystal. For example, when growing a silicon carbide single crystal, the distance is set such that the seed crystal can be prevented from spreading in the radial direction depending on the temperature of the guide. Thus, the guide is arranged in the vicinity of the silicon carbide single crystal substrate 3.
[0058]
When the silicon carbide single crystal 10 is grown by performing the same process as in the first embodiment using the crystal growth apparatus configured as described above, the guide becomes high temperature. Crystal growth of single crystal 10 is suppressed, and silicon carbide single crystal 10 is formed in a shape corresponding to the shape of the guide.
[0059]
Thereby, bulk silicon carbide single crystal 10 in the state in which the orientation flat is formed is obtained.
[0060]
The characteristics of crystals vary depending on the plane orientation, for example, the characteristics of slices and polishing after crystal growth vary greatly depending on the processing direction. If the difficult workability of SiC is taken into consideration, the labor is greatly increased. However, since the silicon carbide single crystal 10 in the state in which the orientation flat is formed is obtained as described above, such trouble can be eliminated.
[0061]
If the growth crystal has an orientation flat, the orientation can be known without measuring the direction by X-ray measurement, and the post-crystallization process becomes easy. In fact, taking the grown crystal out of the graphite crucible and measuring the plane orientation itself takes considerable effort. In particular, in the case of difficult-to-work materials such as SiC, the labor is increased.
[0062]
(Third embodiment)
FIG. 3A shows the overall configuration of the crystal manufacturing apparatus in the present embodiment. Moreover, CC sectional drawing of Fig.3 (a) is shown in FIG.3 (b), and DD sectional drawing is shown in FIG.3 (c). In addition, since the crystal manufacturing apparatus of this embodiment has the structure substantially the same as 1st Embodiment, description is abbreviate | omitted about the same part.
[0063]
As shown in FIG. 3A, the lid 2 is provided with a pedestal 2a, and a silicon carbide single crystal substrate 3 serving as a seed crystal is disposed on the surface of the pedestal 2a. Further, as shown in FIG. 3B, pedestal 2a is formed in a hexagonal shape, and silicon carbide single crystal substrate 3 serving as a seed crystal is formed in a hexagonal shape. Here, silicon carbide single crystal substrate 3 is formed in a hexagonal shape formed of a mold surface {11-00} plane. Thus, by forming both base 2a and silicon carbide single crystal substrate 3 in a hexagonal shape, the surface temperature of silicon carbide single crystal substrate 3 can be kept more uniform.
[0064]
Further, the size of the hollow portion of the guide 7 (in this specification, the distance from the center of the guide 7 to the inner wall surface of the guide) is set to the size of the silicon carbide single crystal substrate 3 (in this specification, the silicon carbide single crystal substrate). 3), and the silicon carbide single crystal 10 is enlarged as the crystal grows. Then, as shown in FIG. 5D, the silicon carbide single crystal 10 on the silicon carbide single crystal substrate 3 passes through the hollow portion of the guide 7 and arrives at the inner wall surface of the guide 7 and forms a hexagon. It grows along the wall. At this time, the mold surface {11-00} surface of the silicon carbide single crystal 10 and the inner wall surface of the guide 7 are made to coincide. Thereby, silicon carbide single crystal 10 has a substantially hexagonal column shape that becomes a mold surface {11-00} plane in a portion that passes through guide 7, and a cross-sectional shape of silicon carbide single crystal 10 and guide 7 when viewed from the growth direction. Is almost similar.
[0065]
Since the guide 7 is heated by the temperature transmitted from the graphite crucible, the silicon carbide single crystal 10 receives the temperature of the guide 7 and grows in a state where a minute gap is provided between the guide 7 and the guide 7. Become. For this reason, the silicon carbide single crystal 10 can be easily taken out from the guide 7.
[0066]
Further, the length of the guide 7 in the growth direction of the silicon carbide single crystal 10 is set to be longer than the silicon carbide single crystal 10 to be grown, and the silicon carbide single crystal 10 always follows the inner wall surface of the guide 7. To grow.
[0067]
In this way, the silicon carbide single crystal 10 passes through the hollow portion of the guide 7 or grows along the inner wall surface of the guide 7 so that the growth surface is flat and ideal hexagonal columnar silicon carbide. Single crystal ingots can be formed. For this reason, generation of crack nuclei, which is a cause of generation of crack defects, can be suppressed.
[0068]
In addition, since the mold surface {11-00} plane of silicon carbide single crystal 10 and the inner wall surface of guide 7 coincide with each other, the size of silicon carbide single crystal substrate 3 is larger than the size of the hollow portion of guide 7. Even if it is small, the generation of cracks due to atomic collisions within the growth plane of silicon carbide single crystal 10 can be suppressed.
[0069]
Further, since silicon carbide single crystal substrate 3 serving as a seed crystal is formed of a hexagonal shape having a mold surface {11-00}, the shape of the seed crystal is taken over by silicon carbide single crystal 10 and cracks are observed from the initial growth stage. The generation of nuclei can be suppressed.
[0070]
In the present embodiment, the guide 7 is formed of a thin cylindrical member. However, as shown in FIG. 4, the guide 7 may be formed of a thick member having a reduced inner diameter of the crucible body 1. Further, in this embodiment, the inner wall surface of the guide 7 is parallel to the growth direction of the silicon carbide single crystal 10, but as shown in FIG. Also good.
[0071]
(Fourth embodiment)
FIG. 6A shows the overall configuration of the crystal manufacturing apparatus in the present embodiment. Moreover, EE sectional drawing of Fig.6 (a) is shown in FIG.6 (b), and FF sectional drawing is shown in FIG.6 (c). In addition, since the crystal manufacturing apparatus of this embodiment has the structure substantially the same as 3rd Embodiment, description is abbreviate | omitted about the same part.
[0072]
In the present embodiment, as shown in FIG. 6B, the guide 7 is formed in a disk shape having a hexagonal hollow portion. The length of the guide 7 in the growth direction of the silicon carbide single crystal 10 is made shorter than that of the silicon carbide single crystal 10 to be grown. The guide 7 is arranged in front of the silicon carbide single crystal substrate 3 in the growth direction of the silicon carbide single crystal 10.
[0073]
In such a case, as shown in FIG. 6A, as the silicon carbide single crystal 10 grows, a sufficiently free space for the grown crystal that has passed through the guide 7 expands. As shown, the grown crystal once formed into an ideal shape by the guide 7 grows while maintaining a substantially hexagonal shape constituted by the {11-00} plane as it is.
[0074]
Therefore, an ideal hexagonal columnar silicon carbide single crystal ingot having a flat growth surface can be formed, and the generation of crack nuclei that can cause crack defects can be suppressed.
[0075]
(Fifth embodiment)
FIG. 7A shows the overall configuration of the crystal manufacturing apparatus in the present embodiment. 7A is a sectional view taken along line GG in FIG. 7A, FIG. 7C is a sectional view taken along line H-H, and FIG. 7A is a sectional view taken along line II in FIG. Shown in (d). In addition, since the crystal manufacturing apparatus of this embodiment has the structure substantially the same as 4th Embodiment, description is abbreviate | omitted about the same part.
[0076]
As shown in FIGS. 7A and 7B, the size of the silicon carbide single crystal substrate 3 is determined from the size of the pedestal 2a (in this specification, the distance from the center position of the pedestal 2a to the outer edge). It is also bigger. That is, all the sides of silicon carbide single crystal substrate 3 are made larger than each side of base 2a having a hexagonal shape, and the surface of base 2a on which silicon carbide single crystal substrate 3 is arranged is silicon carbide single crystal substrate 3. To cover the entire surface. In this way, the portion protruding from the pedestal 2a becomes high temperature and sublimates during growth by thermal etching, so that the crystal defects at the outer edge portion of the silicon carbide single crystal substrate 3 are removed by thermal etching, and the nucleus of crack generation Can be removed.
[0077]
Further, the size of the hollow portion of the guide 7 is made smaller than the size of the silicon carbide single crystal substrate 3.
[0078]
In such a case, the silicon carbide single crystal 10 grows in the longitudinal direction while expanding in the radial direction until reaching the guide 7. At this time, a crack defect occurs in the outer peripheral portion of silicon carbide single crystal 10.
[0079]
When silicon carbide single crystal 10 reaches guide 7, silicon carbide single crystal 10 continues to grow in a region smaller than the size of the hollow portion of guide 7. Thereby, only the area | region in which the crack defect is not formed grows among the silicon carbide single crystals 10, and when passing through the hollow part of the guide 7, it can be set as the favorable silicon carbide single crystal 10 with few crack defects.
[0080]
After passing through the guide 7, as in the fourth embodiment, the silicon carbide single crystal 10 grows while expanding in the radial direction, but the grown crystal once formed into an ideal shape by the guide 7 has a {11-00} plane. It grows while maintaining a substantially hexagonal shape.
[0081]
Therefore, an ideal hexagonal columnar silicon carbide single crystal ingot having a flat growth surface can be formed, and the generation of crack nuclei that can cause crack defects can be suppressed.
[0082]
In the present embodiment, the case where the length of the guide 7 in the growth direction of the silicon carbide single crystal 10 is shorter than that of the silicon carbide single crystal 10 to be grown has been described. However, as in the third embodiment, the growth is performed. It is also possible to make it longer than the silicon carbide single crystal 10 to be made.
[0083]
In this case, since the silicon carbide single crystal 10 arrives at the guide 7 and grows along the inner wall surface of the guide 7, the generation of crack nuclei that cause more crack defects is generated. Can be suppressed.
[0084]
Also in this case, as shown in FIGS. 8A and 8B, the inner wall surface of the guide 7 is inclined with respect to the growth direction of the silicon carbide single crystal 10 to increase the size of the hollow portion of the guide 7. You may comprise as follows. For example, the inclination angle can be set to 5 to 80 degrees. Also in this case, if the silicon carbide single crystal 10 is expanded so that expansion in the radial direction is suppressed, it is possible to prevent the formation of crystal defects at the outer edge portion of the silicon carbide single crystal 10. it can. In addition, although the inclination range in which expansion in the radial direction of silicon carbide single crystal 10 is suppressed is in the range of 0 to 30 degrees, whether or not it is limited is determined by the difference between the raw material, temperature, and growth surface temperature.
[0085]
In the present embodiment, the case where the silicon carbide single crystal substrate 3 to be a seed crystal is hexagonal has been described. However, since the shape of the silicon carbide single crystal 10 grown by the guide 7 can be regulated, the silicon carbide single crystal 10 As long as the portion that passes through the guide 7 is a good portion without crack defects, other shapes may be used. For example, it may be circular as shown in FIG.
[0086]
Moreover, since the effect of this embodiment can be acquired if the silicon carbide single crystal 10 can be narrowed down in the radial direction, the inner wall surface of the guide 7 may be circular.
[0087]
(Other embodiments)
In the above-described embodiment, the shape of the guide is described as a hexagonal column shape or a columnar shape provided with a notch, but the guide may be configured in other shapes. For example, when the diameter of the silicon carbide single crystal substrate 3 is small and it is desired to increase the diameter, but to control the amount of expansion in the radial direction, as the silicon carbide single crystal 10 grows, the radial direction increases as shown in FIG. If the guide 7b is configured with an expanded shape, and the amount of expansion is set to be smaller than the expansion of the diameter of the silicon carbide single crystal normally obtained when the guide 7b is not provided, the above-described control is possible. Good.
[0088]
In the above embodiment, the crystal shape of the silicon carbide single crystal 10 is controlled by providing the guide 7 separately. However, as shown in FIG. 11, the shape of the inner wall of the graphite crucible is the guide 7 shown in the above embodiment. The same effect as the above-described embodiment can be obtained by adopting the shape.
[0089]
In the fifth embodiment, the inner wall surface of the guide 7 is parallel to the growth direction of the silicon carbide single crystal 10, but the inner wall surface of the guide 7 is shown in FIGS. As shown, the silicon carbide single crystal 10 may be deformed so as to be inclined with respect to the growth direction. FIGS. 12A to 12C show cross sections when the guide 7 described on the right side of FIG. 7 is cut in the growth direction of the silicon carbide single crystal 10.
[0090]
For example, as shown in FIG. 12A, the diameter may be increased with respect to the growth direction of the silicon carbide single crystal 10. By doing in this way, after the silicon carbide single crystal 10 reaches | attains the guide 7, it can be made to grow so that it may expand smoothly in a radial direction.
[0091]
Further, as shown in FIG. 12B, the diameter may be narrowed with respect to the growth direction of the silicon carbide single crystal 10. By doing in this way, after the silicon carbide single crystal 10 reaches the guide 7, it is squeezed in the radial direction, so that the silicon carbide single crystal 10 can be actively suppressed from expanding in the radial direction, and the silicon carbide single crystal Ten crack defects can be eliminated.
[0092]
  Further, as shown in FIG. 12C, the radial direction may be increased after the radial direction is narrowed with respect to the growth direction of the silicon carbide single crystal 10. Thereby, the effects of both the structures shown in FIGS. 11A and 11B can be obtained..
  In addition, when indicating the orientation of a crystal, a bar (-) should be added above the number, but due to restrictions on expression, a bar is added after the number in this specification. .
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a crystal growth apparatus used in a first embodiment of the present invention.
FIG. 2 is a diagram showing an overall configuration of a crystal growth apparatus used in a second embodiment of the present invention.
FIG. 3 is a diagram showing an overall configuration of a crystal growth apparatus used in a third embodiment of the present invention.
FIG. 4 is a diagram showing an overall configuration of a crystal growth apparatus in another example of the third embodiment.
FIG. 5 is a diagram showing an overall configuration of a crystal growth apparatus in another example of the third embodiment.
FIG. 6 is a diagram showing an overall configuration of a crystal growth apparatus used in a fourth embodiment of the present invention.
FIG. 7 is a diagram showing an overall configuration of a crystal growth apparatus used in a fifth embodiment of the present invention.
FIG. 8 is a diagram showing an overall configuration of a crystal growth apparatus in another example of the fifth embodiment.
FIG. 9 is a diagram showing an overall configuration of a crystal growth apparatus in another example of the fifth embodiment.
FIG. 10 is a diagram showing an overall configuration of a crystal growth apparatus shown in another embodiment.
FIG. 11 is a diagram showing an overall configuration of a crystal growth apparatus according to another embodiment.
FIG. 12 is a diagram showing an overall configuration of a crystal growth apparatus shown in another embodiment.
FIG. 13 is a diagram for explaining a generation mechanism of a crack defect generated with the growth of a silicon carbide single crystal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Crucible body, 2 ... Cover material, 3 ... Silicon carbide single crystal substrate, 4 ... Silicon carbide raw material powder, 7 ... Guide, 10 ... Silicon carbide single crystal.

Claims (22)

A silicon carbide single crystal substrate (3) serving as a seed crystal is disposed in a container (1, 2), and a sublimation gas of a silicon carbide raw material is supplied to the silicon carbide single crystal substrate. In the method for producing a silicon carbide single crystal, on which a silicon carbide single crystal (10) is grown,
In the vicinity of the silicon carbide single crystal substrate, wall members (7, 7a, 7b) are arranged so as to surround the outer periphery of the silicon carbide single crystal substrate, and when the silicon carbide single crystal is grown, Controlling the growth of the silicon carbide single crystal in the direction of the wall member by making the temperature higher than the sublimation temperature of silicon carbide ,
The wall member has a circular arc shape corresponding to an orientation flat cross section, and a cylindrical shape provided with a hollow portion, and the diameter of the hollow portion of the cylindrical shape is larger than the diameter of the silicon carbide single crystal substrate. A method for producing a silicon carbide single crystal, comprising: arranging the silicon carbide single crystal substrate within the cylindrical hollow portion . The silicon carbide single crystal according to claim 1 , wherein the <112-0> direction or the <11-00> direction of the silicon carbide single crystal substrate is aligned with the orientation flat of the wall member. Method. A silicon carbide single crystal substrate (3) serving as a seed crystal is disposed in a container (1, 2), and a sublimation gas of a silicon carbide raw material is supplied to the silicon carbide single crystal substrate. In the method for producing a silicon carbide single crystal, on which a silicon carbide single crystal (10) is grown,
In the vicinity of the silicon carbide single crystal substrate, wall members (7, 7a, 7b) are arranged so as to surround the outer periphery of the silicon carbide single crystal substrate, and when the silicon carbide single crystal is grown, Including controlling the growth of the silicon carbide single crystal in the direction of the wall member by making the temperature higher than the sublimation temperature of silicon carbide,
A method for producing a silicon carbide single crystal, wherein the wall member is formed in a hexagonal column shape provided with a hollow portion, and the silicon carbide single crystal substrate is disposed in the hexagonal column-shaped hollow portion. The carbonization according to claim 3, wherein the <112-0> direction or the <11-00> direction of the silicon carbide single crystal is aligned with one corner of the wall member having a hexagonal column shape. A method for producing a silicon single crystal. A silicon carbide single crystal substrate (3) serving as a seed crystal is disposed in a container (1, 2), and a sublimation gas of a silicon carbide raw material is supplied to the silicon carbide single crystal substrate. In the method for producing a silicon carbide single crystal, on which a silicon carbide single crystal (10) is grown,
In the vicinity of the silicon carbide single crystal substrate, wall members (7, 7a, 7b) are arranged so as to surround the outer periphery of the silicon carbide single crystal substrate, and when the silicon carbide single crystal is grown, Including controlling the growth of the silicon carbide single crystal in the direction of the wall member by making the temperature higher than the sublimation temperature of silicon carbide,
The wall member is configured to have a conical hollow portion whose radial direction expands with the growth of the silicon carbide single crystal, and in the vicinity of the silicon carbide single crystal substrate, the cross-sectional shape is circular, A method for producing a silicon carbide single crystal, wherein the silicon carbide single crystal substrate has a conical shape whose cross-sectional shape changes to a hexagon as the silicon carbide single crystal substrate grows. 6. The method for producing a silicon carbide single crystal according to claim 5, wherein the wall member has a conical shape inclined at 5 to 80 degrees with respect to a normal direction of the surface of the silicon carbide single crystal substrate. The distance between the wall member and the silicon carbide single crystal substrate is set to be within 5 to 30% of the radius of the silicon carbide single crystal substrate. The manufacturing method of the silicon carbide single crystal of description. A silicon carbide single crystal raw material (4) to be grown and a silicon carbide single crystal substrate (3) to be a seed crystal are arranged in a container (1, 2), and the raw material is sublimated to form the silicon carbide single crystal substrate. In a silicon carbide single crystal manufacturing apparatus for growing a silicon carbide single crystal (10) on the substrate,
In the vicinity of the silicon carbide single crystal substrate, a wall member is disposed so as to surround the outer periphery of the silicon carbide single crystal substrate, and when the silicon carbide single crystal is crystal-grown, the wall member is lower than the sublimation temperature of silicon carbide. It is configured to be hot,
The wall member has a cylindrical shape with a hollow portion, and the diameter of the hollow portion of the cylindrical shape is larger than the diameter of the silicon carbide single crystal substrate, and the cross-sectional shape of the wall member has an orientation. An apparatus for producing a silicon carbide single crystal, characterized in that it has an arc shape corresponding to a flat shape. A silicon carbide single crystal raw material (4) to be grown and a silicon carbide single crystal substrate (3) to be a seed crystal are arranged in a container (1, 2), and the raw material is sublimated to form the silicon carbide single crystal substrate. In a silicon carbide single crystal manufacturing apparatus for growing a silicon carbide single crystal (10) on the substrate,
In the vicinity of the silicon carbide single crystal substrate, a wall member is disposed so as to surround the outer periphery of the silicon carbide single crystal substrate, and when the silicon carbide single crystal is crystal-grown, the wall member is lower than the sublimation temperature of silicon carbide. It is configured to be hot,
The said wall member is comprised by the hexagonal column shape provided with the hollow part, The manufacturing apparatus of the silicon carbide single crystal characterized by the above-mentioned. A silicon carbide single crystal substrate (3) serving as a seed crystal is disposed in a container (1, 2), and a sublimation gas of a silicon carbide raw material is supplied to the silicon carbide single crystal substrate. In the method for producing a silicon carbide single crystal, on which a silicon carbide single crystal (10) is grown,
A wall member (7, 7a, 7b) having a hexagonal hollow portion is disposed so as to surround the outer periphery of the silicon carbide single crystal substrate, and the grown silicon carbide single crystal passes through the hollow portion of the wall member. A method for producing a silicon carbide single crystal, wherein In a portion passing through the hollow portion, the silicon carbide single crystal becomes a mold surface {11-00} plane and name Ru hexagonal prism shape, the cross-sectional shape of the wall member and the silicon carbide single crystal as seen from the direction of growth method for producing a silicon carbide single crystal according to claim 10, characterized in that such a phase Nigata. The method for producing a silicon carbide single crystal according to claim 10 or 11 , wherein a minute gap is provided between the wall member and the silicon carbide single crystal. 13. The silicon carbide single crystal substrate according to claim 10 , wherein the silicon carbide single crystal substrate is arranged so that a mold surface {11-00} plane of the silicon carbide single crystal and a hexagonal inner wall surface of the wall member coincide with each other. The manufacturing method of the silicon carbide single crystal as described in any one. The method of manufacturing a silicon carbide single crystal according to claim 13 , wherein the silicon carbide single crystal substrate has a hexagonal shape formed of a mold surface {11-00}. The length of the wall member in the growth direction of the silicon carbide single crystal is made longer than the silicon carbide single crystal to be grown, so that the silicon carbide single crystal grows along the inner wall of the wall member. The method for producing a silicon carbide single crystal according to any one of claims 10 to 14 , wherein: The length in the growth direction of the silicon carbide single crystal of the wall member is shorter than the silicon carbide single crystal to be grown, and after the silicon carbide single crystal has grown longer than the wall member, said silicon carbide single crystal mold surface {11-00} according to any one of claims 10 to 14, wherein the growing so that hexagon shape that consists in surface of the silicon carbide single crystal Production method. The size of the hollow portion of the wall member is made smaller than the size of the silicon carbide single crystal substrate, the wall member is disposed in front of the silicon carbide single crystal substrate in the growth direction of the silicon carbide single crystal, and the carbonization is performed. after the silicon single crystal has reached the wall member to grow, any one of claims 10 to 16, wherein the silicon carbide single crystal along the inner wall surface of the wall member, characterized in that to grow A method for producing a silicon carbide single crystal according to 1.   The size of the hollow portion of the wall member is made larger than the size of the silicon carbide single crystal substrate, the silicon carbide single crystal is enlarged as it grows, reaches the inner wall surface of the wall member, and extends along the inner wall surface. The method for producing a silicon carbide single crystal according to any one of claims 10 to 16, wherein the silicon carbide single crystal is grown. The silicon carbide single crystal substrate according to any one of claims 10 to 18 , wherein the silicon carbide single crystal substrate is disposed on a pedestal provided in the container, and the shape of the pedestal is a hexagon. Production method. All the sides of the hexagonal silicon carbide single crystal substrate are made larger than the sides of the hexagonal pedestal, and the pedestal surface on which the silicon carbide single crystal substrate is disposed is formed on the silicon carbide single crystal. The method for producing a silicon carbide single crystal according to claim 19 , wherein the entire surface is covered with a substrate. 21. The method for producing a silicon carbide single crystal according to claim 10, wherein an inner wall surface of the wall member is inclined with respect to a growth direction of the silicon carbide single crystal. The method for producing a silicon carbide single crystal according to any one of claims 10 to 21, wherein the wall member has a structure in which a size of the hollow portion is widened with respect to a growth direction of the silicon carbide single crystal. .

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