WO2023068309A1 - SiC基板及びSiC複合基板 - Google Patents
SiC基板及びSiC複合基板 Download PDFInfo
- Publication number
- WO2023068309A1 WO2023068309A1 PCT/JP2022/039004 JP2022039004W WO2023068309A1 WO 2023068309 A1 WO2023068309 A1 WO 2023068309A1 JP 2022039004 W JP2022039004 W JP 2022039004W WO 2023068309 A1 WO2023068309 A1 WO 2023068309A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- sic
- substrate
- point
- intensity
- biaxially oriented
- Prior art date
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 197
- 239000002131 composite material Substances 0.000 title claims description 28
- 238000005424 photoluminescence Methods 0.000 claims abstract description 94
- 239000013078 crystal Substances 0.000 claims description 91
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 14
- 229910052796 boron Inorganic materials 0.000 claims description 14
- 230000007423 decrease Effects 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 8
- 229910010271 silicon carbide Inorganic materials 0.000 description 270
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 260
- 238000000034 method Methods 0.000 description 74
- 239000002243 precursor Substances 0.000 description 43
- 239000000843 powder Substances 0.000 description 39
- 238000010438 heat treatment Methods 0.000 description 28
- 239000002245 particle Substances 0.000 description 28
- 239000002994 raw material Substances 0.000 description 22
- 239000000443 aerosol Substances 0.000 description 15
- 230000015572 biosynthetic process Effects 0.000 description 14
- 238000005229 chemical vapour deposition Methods 0.000 description 14
- 238000000465 moulding Methods 0.000 description 14
- 238000011156 evaluation Methods 0.000 description 13
- 238000005498 polishing Methods 0.000 description 13
- 239000000243 solution Substances 0.000 description 13
- 238000009826 distribution Methods 0.000 description 11
- 230000007547 defect Effects 0.000 description 10
- 239000007789 gas Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 9
- 238000004458 analytical method Methods 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 229910052580 B4C Inorganic materials 0.000 description 6
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 6
- 238000000151 deposition Methods 0.000 description 6
- 229910003460 diamond Inorganic materials 0.000 description 6
- 239000010432 diamond Substances 0.000 description 6
- 238000001887 electron backscatter diffraction Methods 0.000 description 6
- 238000010304 firing Methods 0.000 description 6
- 238000000227 grinding Methods 0.000 description 6
- 238000003384 imaging method Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 239000012298 atmosphere Substances 0.000 description 5
- 150000001639 boron compounds Chemical class 0.000 description 5
- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 description 5
- 238000002230 thermal chemical vapour deposition Methods 0.000 description 5
- 239000006061 abrasive grain Substances 0.000 description 4
- 238000005092 sublimation method Methods 0.000 description 4
- 238000000137 annealing Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000007731 hot pressing Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 238000013507 mapping Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000000859 sublimation Methods 0.000 description 3
- 230000008022 sublimation Effects 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 150000002500 ions Chemical group 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 230000008707 rearrangement Effects 0.000 description 2
- 238000007788 roughening Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 1
- 241000156302 Porcine hemagglutinating encephalomyelitis virus Species 0.000 description 1
- 229910003902 SiCl 4 Inorganic materials 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910021431 alpha silicon carbide Inorganic materials 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- -1 boron carbide Chemical class 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001739 density measurement Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 238000007606 doctor blade method Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009760 electrical discharge machining Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000879 optical micrograph Methods 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000005049 silicon tetrachloride Substances 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- 238000003826 uniaxial pressing Methods 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/36—Carbides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/20—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy
- H01L21/2003—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy characterised by the substrate
- H01L21/2015—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy characterised by the substrate the substrate being of crystalline semiconductor material, e.g. lattice adaptation, heteroepitaxy
Definitions
- the present invention relates to SiC substrates and SiC composite substrates.
- SiC silicon carbide
- SiC power devices power semiconductor devices using SiC materials
- SiC power devices are superior to those using Si semiconductors in terms of miniaturization, low power consumption, and high efficiency, so they are expected to be used in various applications.
- SiC power devices converters, inverters, on-board chargers, etc. for electric vehicles (EV) and plug-in hybrid vehicles (PHEV) can be made smaller and more efficient.
- EV electric vehicles
- PHEV plug-in hybrid vehicles
- the solution growth method is known as a method for reducing defects in the wafer, particularly threading screw dislocations (TSD) which are said to cause breakdown voltage deterioration.
- TSD threading screw dislocations
- Patent Document 1 Japanese Patent Application Laid-Open No. 2014-043369
- a macrostep made of a SiC single crystal and having a height of more than 70 nm is formed to obtain a second seed crystal.
- a method for manufacturing a SiC single crystal comprising: According to this manufacturing method, it is described that a SiC single crystal with few threading screw dislocations can be obtained.
- problems such as macro defects such as solvent inclusions and heterogeneous polymorphs due to surface roughening.
- Non-Patent Document 1 Lixia Zhao et al. "Surface defects in 4H-SiC homoepitaxial layers” Nanotechnology and Precision Engineering 3 (2020) 229-234
- a SiC epitaxial layer is obtained by chemical vapor deposition, It discloses that the morphology and structure of this surface defect were investigated, and generally the TSD density of the SiC substrate is 300 to 500 cm ⁇ 2 .
- Non-Patent Document 1 most of the TSD on the substrate is propagated to the epitaxial layer, so it is difficult to reduce the TSD density on the substrate surface significantly below 300 cm ⁇ 2 . Therefore, further reduction of the TSD density on the SiC substrate surface is desired.
- the present inventors have recently found that a biaxially oriented SiC layer that satisfies predetermined conditions when analyzed by photoluminescence (PL) results in a SiC substrate with a very low TSD density on the surface.
- PL photoluminescence
- an object of the present invention is to provide a SiC substrate having a very low surface TSD density.
- a SiC substrate comprising a biaxially oriented SiC layer, wherein the surface of the biaxially oriented SiC layer is analyzed by photoluminescence (PL), and the horizontal axis is the distance ( ⁇ m) in the [11-20] direction, and , PL intensity I plotted on the vertical axis, (i) the graph has a shape that repeats maxima and minima, where the maxima are the first, second and third closest points on the left and right of the graph, totaling 6 points; is defined as a point that gives a higher PL intensity I than each of the PL intensity I of , and the local minimum point is a total of 6 points consisting of the first closest point, the second closest point, and the third closest point on the left and right defined as the point giving a lower PL intensity I than each of the PL intensities I of (ii) Let M be the maximum value of the PL intensity I at a certain maximum point PM , and a minimum point located
- a SiC substrate provided with a biaxially oriented SiC layer wherein in an image obtained by analyzing the surface of the biaxially oriented SiC layer by photoluminescence (PL), Previtt about the [11-20] direction of the image
- a graph is obtained by processing with a filter and plotting the distance ( ⁇ m) in the [11-20] direction on the horizontal axis and the PL intensity IF on the vertical axis
- the graph has a shape that repeats a plurality of local maxima, where the local maxima are the first, second and third closest points on the left and right of the graph, totaling six points; defined as the point giving a higher PL intensity IF than each of the PL intensity IF ,
- the biaxially oriented SiC layer is oriented in the c-axis direction and the a-axis direction.
- the graph shows a constant as the depth decreases.
- FIG. 1 is a longitudinal sectional view of a SiC composite substrate 10;
- FIG. 4 is a manufacturing process diagram of the SiC composite substrate 10.
- FIG. It is a schematic cross section showing the configuration of an aerosol deposition (AD) apparatus.
- 2 is a photoluminescence (PL) imaging image in the (0001) plane of the biaxially oriented SiC layer obtained in Example 1.
- FIG. The horizontal axis represents the distance ( ⁇ m) in the [11-20] direction, and the vertical axis represents the PL intensity I, which was created based on the PL imaging image of the (0001) plane of the biaxially oriented SiC layer obtained in Example 1.
- FIG. 4 is a graph plotted on 4 is an image obtained by processing a PL imaging image on the (0001) plane of the biaxially oriented SiC layer obtained in Example 1 with a Prewitt filter.
- the distance in the [11-20] direction ( ⁇ m) is plotted on the horizontal axis and the PL intensity IF is plotted on the vertical axis.
- the horizontal axis represents the depth ( ⁇ m) from the (0001) plane to the arbitrary (000-1) plane of the biaxially oriented SiC layer obtained in Example 1, and the threading screw dislocation (TSD) density (cm ⁇ 2 ). is plotted on the vertical axis.
- 4 is an optical microscope image showing a step-terrace structure on the substrate surface of a SiC substrate obtained by a solution growth method, published in Non-Patent Document 2.
- the SiC substrate according to the invention is a SiC substrate with a biaxially oriented SiC layer.
- the surface of this biaxially oriented SiC layer is analyzed by photoluminescence (PL), and a graph plotted with the distance ( ⁇ m) in the [11-20] direction as the horizontal axis and the PL intensity I as the vertical axis is shown.
- PL photoluminescence
- FIG. 5 which will be described later, (i) it has a peculiar shape in which local maximum points and local minimum points are repeated.
- the maximum point is defined as a point that gives a higher PL intensity I than each of the 6 points in total consisting of the first, second and third closest points on the left and right sides of the maximum point.
- the local minimum point is defined as a point that gives a lower PL intensity I than each of the 6 PL intensities I in total consisting of the first, second and third closest points on the left and right. be.
- this graph is under the following conditions: (ii) Let M be the maximum value of the PL intensity I at a certain maximum point PM , and the minimum point P that is longer in the horizontal axis direction than that maximum point PM and that is closest to that maximum point PM When the minimum value of the PL intensity I at m is m, the ratio of M/m is 1.05 or more, and (iii) [11-20] between the maximum point P M and the minimum point P m It satisfies that the directional distance L is 15 to 150 ⁇ m.
- the [11-20] direction of the image is processed with a Prewitt filter, and the [11-20] direction
- a graph is obtained by plotting the distance ( ⁇ m) on the horizontal axis and the PL intensity IF on the vertical axis, for example, as shown in FIG. have.
- the maximum point is a point that gives a higher PL intensity IF than each of the total 6 points consisting of the first, second and third closest points on the left and right sides of the PL intensity IF . Defined.
- a biaxially oriented SiC layer that satisfies predetermined conditions can provide a SiC substrate with a very low TSD density on the surface. Moreover, since such a SiC substrate can be produced without using a solution growth method, macro defects on the substrate surface are less likely to occur.
- the surface of the biaxially oriented SiC layer is analyzed by PL, the horizontal axis is the distance ( ⁇ m) in the [11-20] direction, and the PL intensity
- M be the maximum value of the PL intensity I at a certain maximum point PM
- the ratio of M/ m is 1.05 or more, where m is the minimum value of the PL intensity I at the minimum point Pm closest to the maximum point PM (hereinafter referred to as condition (ii)).
- condition (ii) the upper limit of the M/m ratio is not particularly limited, it is preferably 1.05 to 1.80.
- the distance L in the [11-20] direction between the maximum point PM and the minimum point Pm is 15 to 150 ⁇ m (hereinafter, condition (iii )), preferably 50 to 150 ⁇ m, more preferably 50 to 120 ⁇ m, even more preferably 50 to 100 ⁇ m.
- the above graph typically has a regular pattern in which waveforms including local maximum points and local minimum points are repeated at regular intervals, as shown in FIG. 5, which will be described later.
- at least one of a plurality of maximum points (and a corresponding minimum point) on a predetermined measurement line segment parallel to the [11-20] direction meets the above conditions (ii) and If (iii) is satisfied, the SiC substrate is assumed to satisfy the above conditions (ii) and (iii). More preferably, however, at least two of the local maxima (and their corresponding local minima) satisfy conditions (ii) and (iii) above, and even more preferably at least three of the local maxima.
- the biaxially oriented SiC layer constituting the SiC substrate of the present invention is an image obtained by PL analysis of the surface of the biaxially oriented SiC layer, Prewitt filter for the [11-20] direction of the image to obtain a graph in which the distance ( ⁇ m) in the [11-20] direction is plotted on the horizontal axis and the PL intensity IF is plotted on the vertical axis.
- the distance in the [11-20] direction is longer than M1 , and the distance L F in the [11-20] direction between the local maximum point P M1 and the closest local maximum point P M2 is 30 to 300 ⁇ m (
- condition (v)) the thickness is preferably 100 to 300 ⁇ m, more preferably 100 to 240 ⁇ m, further preferably 100 to 200 ⁇ m.
- the graph obtained by processing with the Prewitt filter repeats a plurality of maximum points, as shown in FIG. 7, which will be described later.
- a predetermined measurement line segment eg, a line segment of 500 ⁇ m
- the SiC substrate satisfies the above condition (v). More preferably, however, there are at least two such combinations, and even more preferably three.
- the biaxially oriented SiC layer is preferably oriented in the c-axis direction and the a-axis direction. It is also preferred that the SiC substrate consists of a biaxially oriented SiC layer.
- the biaxially oriented SiC layer may be a SiC single crystal or a mosaic crystal as long as it is oriented in the biaxial directions of the c-axis and the a-axis.
- Mosaic crystals are aggregates of crystals that do not have distinct grain boundaries but have slightly different crystal orientations in one or both of the c-axis and a-axis.
- the orientation evaluation method is not particularly limited, but for example, a known analysis method such as an EBSD (Electron Back Scatter Diffraction Patterns) method or an X-ray pole figure can be used.
- EBSD Electro Back Scatter Diffraction Patterns
- X-ray pole figure inverse pole figure mapping of the surface (plate surface) of the biaxially oriented SiC layer or a cross section perpendicular to the plate surface is measured.
- the substantially in-plane direction of the plate may be oriented in a specific direction (for example, the a-axis) orthogonal to the c-axis.
- the biaxially oriented SiC layer may be oriented biaxially in the substantially normal direction and the substantially in-plane direction, but the substantially normal direction is preferably oriented in the c-axis. The smaller the tilt angle distribution in the substantially normal direction and/or the substantially in-plane direction, the smaller the mosaic property of the biaxially oriented SiC layer.
- the tilt angle distribution is preferably small both in the normal direction and in the plate surface direction, for example ⁇ 5° or less, and more preferably ⁇ 3° or less. .
- the biaxially oriented SiC layer oriented in the c-axis direction and the a-axis direction has a depth ( ⁇ m) on the horizontal axis and the TSD density (cm ⁇ 2 ) on the vertical axis, the graph preferably includes at least a part of the TSD gradient region.
- This TSD graded region effectively contributes to the realization of a SiC substrate with a very low surface TSD density.
- This TSD slope region is a region in which the TSD density decreases with a constant slope a as the depth decreases.
- the absolute value of the slope a is 5.0 cm ⁇ 2 / ⁇ m or more, preferably 5.0 to 25 cm ⁇ 2 / ⁇ m, more preferably 10 to 25 cm ⁇ 2 / ⁇ m, still more preferably 15 to 25 cm ⁇ 2 / ⁇ m. ⁇ m.
- This slope a can be calculated, for example, by obtaining an approximate straight line using the least squares method in the TSD slope region of the above graph.
- "The depth from the (0001) plane, which is the substrate surface, to an arbitrary (000-1) plane” is the (0001) plane of the biaxially oriented SiC layer surface in the biaxially oriented SiC layer on the SiC single crystal substrate. to the back surface direction of the biaxially oriented SiC layer on the side of the SiC single crystal substrate.
- the biaxially oriented SiC layer preferably contains boron in a concentration of 1.0 ⁇ 10 16 to 1.0 ⁇ 10 17 atoms/cm 3 , more preferably 1.0 ⁇ 10 16 to 9.5 ⁇ 10 16 . atoms/ cm3 .
- boron content it is possible to preferably control the PL intensity distribution in the above-described PL graph, and effectively obtain a SiC substrate with a reduced TSD density on the substrate surface. can be done.
- the SiC substrate of the present invention may be a self-supporting substrate consisting of only a SiC substrate, or may be in the form of a SiC composite substrate.
- the SiC composite substrate may include a SiC single crystal substrate and the above-described SiC substrate on the SiC single crystal substrate.
- a SiC single crystal substrate is typically a layer composed of SiC single crystal and has a crystal growth surface.
- the polytype, off angle, and polarity of the SiC single crystal are not particularly limited, but the polytype is preferably 4H or 6H, and the off angle is 0.1 to 12° from the [0001] axis of single crystal SiC.
- the polarity is the Si face. More preferably, the polytype is 4H, the off angle is 1 to 5° from the [0001] axis of the single crystal SiC, and the polarity is the Si plane.
- the SiC substrate of the present invention may be in the form of a self-supporting substrate with a single biaxially oriented SiC layer, or may be in the form of a SiC composite substrate accompanied by a SiC single crystal substrate. Therefore, if desired, the biaxially oriented SiC layer may finally be separated from the SiC single crystal substrate. Separation of the SiC single crystal substrate may be performed by a known method, and is not particularly limited. For example, a method of separating a biaxially oriented SiC layer by a wire saw, a method of separating a biaxially oriented SiC layer by electrical discharge machining, a method of separating a biaxially oriented SiC layer by using a laser, and the like can be mentioned.
- the biaxially oriented SiC layer may be placed on another support substrate after separating the SiC single crystal substrate.
- the material of the other support substrate is not particularly limited, but a suitable material may be selected from the viewpoint of material properties.
- metal substrates such as Cu, ceramic substrates such as SiC and AlN, and the like can be used.
- a SiC composite substrate comprising the SiC substrate of the present invention is produced by (a) forming a predetermined orientation precursor layer on a SiC single crystal substrate, and (b) forming an orientation precursor layer on the SiC single crystal substrate. is heat treated to convert at least a portion near the SiC single crystal substrate to a SiC substrate (biaxially oriented SiC layer), and if desired, (c) processing such as grinding or polishing is performed to expose the surface of the biaxially oriented SiC layer.
- the manufacturing method may be a vapor phase method such as CVD or sublimation, a liquid phase method such as a solution method, or a solid phase method utilizing grain growth.
- the distribution of the PL intensity in the graph obtained by PL can be obtained by controlling the heat treatment conditions in (b) above, or by adding boron or a boron compound (e.g., boron carbide, etc.) when forming the alignment precursor layer in (a) above.
- a SiC substrate having a biaxially oriented SiC layer is analyzed by PL, a SiC substrate having a specific analysis result as described above can be manufactured. can significantly reduce the TSD density on the surface of the SiC composite substrate.
- FIG. 1 is a vertical cross-sectional view of SiC composite substrate 10 (a cross-sectional view when SiC composite substrate 10 is cut vertically along a plane including the central axis of SiC composite substrate 10), and FIG. It is a diagram.
- the SiC composite substrate 10 of this embodiment includes a SiC single crystal substrate 20 and a SiC substrate 30 on the SiC single crystal substrate (corresponding to the SiC substrate of the present invention).
- the orientation precursor layer 40 becomes the SiC substrate (biaxially oriented SiC layer) 30 by heat treatment described later.
- the orientation precursor layer 40 is formed on the crystal growth surface of the SiC single crystal substrate 20 .
- a known method can be adopted as a method for forming the alignment precursor layer 40 .
- the method of forming the alignment precursor layer 40 includes, for example, solid-phase deposition methods such as AD (aerosol deposition) method and HPPD (supersonic plasma particle deposition method) method, sputtering method, vapor deposition method, sublimation method, various CVD ( Chemical vapor deposition) method and other vapor deposition methods, and solution deposition methods and other liquid phase deposition methods can be mentioned, and a method of directly forming the orientation precursor layer 40 on the SiC single crystal substrate 20 can be used. .
- solid-phase deposition methods such as AD (aerosol deposition) method and HPPD (supersonic plasma particle deposition method) method
- sputtering method vapor deposition method, sublimation method
- various CVD ( Chemical vapor deposition) method and other vapor deposition methods and solution deposition methods and other liquid phase deposition methods can be mentioned
- the CVD method for example, a thermal CVD method, a plasma CVD method, a mist CVD method, an MO (organometal) CVD method, or the like can be used.
- the orientation precursor layer 40 a polycrystalline body previously prepared by sublimation, various CVD methods, sintering, or the like may be used and placed on the SiC single crystal substrate 20.
- a method of preparing a molded body of the orientation precursor layer 40 in advance and placing the molded body on the SiC single crystal substrate 20 may be used.
- Such an orientation precursor layer 40 may be a tape compact produced by tape molding, or may be a powder compact produced by pressure molding such as uniaxial pressing.
- the raw material of the alignment precursor layers 40 contains a boron compound.
- the boron compound include, but are not limited to, boron carbide.
- the concentration of boron in the finally obtained biaxially oriented SiC layer can be controlled by controlling the amount of the boron compound added.
- the SiC single crystal substrate 20 can be formed without going through the heat treatment process described later. , epitaxial growth occurs, and the SiC substrate 30 may be deposited.
- the orientation precursor layer 40 is in an unoriented state at the time of formation, that is, amorphous or non-oriented polycrystal, and is preferably oriented using a SiC single crystal as a seed in a subsequent heat treatment step. By doing so, crystal defects reaching the surface of the SiC substrate 30 can be effectively reduced.
- a method of forming the directly oriented precursor layer 40 on the SiC single crystal substrate 20 by the AD method or various CVD methods, or a polycrystalline body separately prepared by a sublimation method, various CVD methods, sintering or the like is used as the SiC single crystal substrate. 20 is preferred.
- the alignment precursor layer 40 can be formed in a relatively short time.
- the AD method is particularly preferred because it does not require a high-vacuum process and its film formation speed is relatively high.
- it is necessary to sufficiently smooth the surface of the polycrystal. is necessary.
- the technique of directly forming the alignment precursor layer 40 is preferable.
- a method of placing a prefabricated compact on the SiC single crystal substrate 20 is also preferable as a simple method. need.
- known conditions can be used for either method, the following describes a method of forming a directly aligned precursor layer 40 on a SiC single crystal substrate 20 by an AD method or a thermal CVD method, and a method of forming a prefabricated molded body into a SiC single crystal. A method of mounting on the crystal substrate 20 will be described.
- the AD method is a technique in which fine particles or fine particle raw materials are mixed with gas to form an aerosol, and the aerosol is sprayed at high speed from a nozzle to collide with a substrate to form a coating, and is characterized by being able to form a coating at room temperature.
- FIG. 3 shows an example of a film forming apparatus (AD apparatus) used in such an AD method.
- the AD apparatus 50 shown in FIG. 3 is configured as an apparatus used for the AD method in which raw material powder is jetted onto a substrate under an atmosphere of pressure lower than the atmospheric pressure.
- the AD device 50 includes an aerosol generating section 52 that generates an aerosol of raw material powder containing raw material components, and a film forming section 60 that injects the raw material powder onto the SiC single crystal substrate 20 to form a film containing the raw material components.
- the aerosol generation unit 52 includes an aerosol generation chamber 53 that contains raw material powder and receives carrier gas supplied from a gas cylinder (not shown) to generate an aerosol, a raw material supply pipe 54 that supplies the generated aerosol to the film formation unit 60, It has an aerosol generation chamber 53 and a vibrator 55 for applying vibrations to the aerosol therein at a frequency of 10 to 100 Hz.
- the film forming section 60 includes a film forming chamber 62 for injecting an aerosol onto the SiC single crystal substrate 20, a substrate holder 64 arranged inside the film forming chamber 62 for fixing the SiC single crystal substrate 20, and the substrate holder 64 being arranged in an X direction. and an XY stage 63 that moves in the axial-Y direction.
- the film forming section 60 includes an injection nozzle 66 having a slit 67 formed at its tip for injecting an aerosol onto the SiC single crystal substrate 20 and a vacuum pump 68 for reducing the pressure in the film forming chamber 62 .
- the injection nozzle 66 is attached to the tip of the raw material supply pipe 54 .
- the AD method it is known that depending on the film formation conditions, pores may be generated in the film or the film may become a compact. For example, it is easily affected by the collision speed of the raw material powder against the substrate, the particle size of the raw material powder, the aggregation state of the raw material powder in the aerosol, the injection amount per unit time, and the like.
- the collision speed of the raw material powder against the substrate is affected by the differential pressure between the film formation chamber 62 and the injection nozzle 66, the opening area of the injection nozzle, and the like. Therefore, it is necessary to appropriately control these factors in order to obtain a dense alignment precursor layer.
- the raw material gas is not particularly limited, but silicon tetrachloride (SiCl 4 ) gas and silane (SiH 4 ) gas are used as Si supply sources, and methane (CH 4 ) gas and propane (C 3 H 8 ) gas or the like can be used.
- the film formation temperature is preferably 1000 to 2200.degree. C., more preferably 1100 to 2000.degree. C., even more preferably 1200 to 1900.degree.
- the orientation precursor layer 40 when the orientation precursor layer 40 is formed on the SiC single crystal substrate 20 using the thermal CVD method, epitaxial growth may occur on the SiC single crystal substrate 20 to form the SiC substrate 30. .
- the orientation precursor layer 40 is not oriented at the time of its fabrication, that is, is amorphous or non-oriented polycrystal, and crystal rearrangement may occur during the heat treatment process using a SiC single crystal as a seed crystal. preferable.
- the film formation temperature, Si source and C source gas flow rates and their ratios, film formation pressure, etc. are affected. It has been known.
- the film formation temperature is preferably low, preferably less than 1700° C., more preferably 1500° C. or less, and even more preferably 1400° C. or less.
- the film formation temperature is too low, the film formation rate itself will also decrease, so from the viewpoint of the film formation rate, a higher film formation temperature is preferable.
- the orientation precursor layer 40 can be produced by molding raw material powder of the orientation precursor.
- the orientation precursor layer 40 is a press molding.
- the press-formed body can be produced by press-molding the raw material powder of the orientation precursor based on a known technique. It may be produced by pressing with a pressure of up to 300 kgf/cm 2 .
- the molding method is not particularly limited, and in addition to press molding, tape molding, extrusion molding, cast molding, doctor blade method, and any combination thereof can be used.
- additives such as a binder, a plasticizer, a dispersant, and a dispersion medium are appropriately added to the raw material powder to form a slurry, and the slurry is passed through a thin slit-shaped discharge port to form a sheet.
- Dispensing and molding are preferred.
- the thickness of the sheet-shaped molding is not limited, it is preferably 5 to 500 ⁇ m from the viewpoint of handling. Further, when a thick orientation precursor layer is required, a large number of such sheet moldings may be stacked to obtain a desired thickness.
- the compact may contain additives such as a sintering aid in addition to the SiC raw material.
- a SiC substrate 30 is produced by heat-treating a laminate obtained by laminating or placing an orientation precursor layer 40 on a SiC single crystal substrate 20.
- the heat treatment method is not particularly limited as long as epitaxial growth occurs using the SiC single crystal substrate 20 as a seed, and a known heat treatment furnace such as a tubular furnace or a hot plate can be used.
- a known heat treatment furnace such as a tubular furnace or a hot plate
- pressure heat treatments such as hot pressing and HIP, and combinations of normal pressure heat treatments and pressure heat treatments can also be used.
- the heat treatment atmosphere can be selected from vacuum, nitrogen, and inert gas atmospheres.
- the heat treatment temperature is preferably 1700-2700°C.
- the heat treatment temperature is preferably 1700° C. or higher, more preferably 1850° C. or higher, still more preferably 2000° C. or higher, and particularly preferably 2200° C. or higher.
- the heat treatment temperature is preferably 2700° C. or lower, more preferably 2500° C. or lower.
- the heat treatment conditions affect the PL intensity distribution in the graph obtained from the PL of the surface of the biaxially oriented SiC layer, so it is preferable to appropriately control the conditions (for example, heat treatment temperature and holding time).
- the heat treatment temperature is preferably 2000 to 2700°C, more preferably 2200 to 2600°C, still more preferably 2400 to 2500°C.
- the holding time is preferably 2 to 30 hours, more preferably 4 to 20 hours.
- the heat treatment temperature and holding time are also related to the thickness of the SiC substrate 30 produced by epitaxial growth, and can be appropriately adjusted.
- the alignment precursor layer 40 when using a pre-fabricated molded body as the alignment precursor layer 40, it is necessary to sinter it during the heat treatment, and high-temperature normal pressure firing, hot pressing, HIP, or a combination thereof is suitable.
- the surface pressure is preferably 50 kgf/cm 2 or more, more preferably 100 kgf/cm 2 or more, still more preferably 200 kgf/cm 2 or more, with no particular upper limit.
- the sintering temperature is not particularly limited as long as sintering and epitaxial growth occur.
- the firing conditions affect the PL intensity distribution in the graph obtained from the PL of the surface of the biaxially oriented SiC layer, it is preferable to appropriately control the conditions (for example, firing temperature and holding time).
- the firing temperature is preferably 1700 to 2700°C.
- the holding time is preferably 2 to 18 hours.
- the atmosphere during firing can be selected from vacuum, nitrogen, inert gas atmosphere, or mixed gas of nitrogen and inert gas.
- SiC powder as a raw material may be either ⁇ -SiC powder or ⁇ -SiC powder, but ⁇ -SiC powder is preferable.
- the SiC powder preferably consists of SiC particles with an average particle size of 0.01 to 100 ⁇ m. Note that the average particle diameter refers to the average value obtained by observing the powder with a scanning electron microscope and measuring the unidirectional maximum diameter of 100 primary particles.
- the crystals in the orientation precursor layer 40 grow from the crystal growth surface of the SiC single crystal substrate 20 while being oriented along the c-axis and the a-axis. , it changes to the SiC substrate 30 .
- a SiC composite substrate including the produced SiC substrate 30 has a reduced TSD density on the substrate surface. The reason for this is unknown, but it is believed that the distribution of the PL intensity reflects the step-terrace structure that occurs during crystal growth, and the TSDs were converted to stacking faults along with the crystal growth.
- the present invention is by no means limited to the above-described embodiments, and can be implemented in various forms as long as they fall within the technical scope of the present invention.
- only one layer of SiC substrate 30 is provided on SiC single crystal substrate 20, but two or more layers may be provided.
- the alignment precursor layer 40 is laminated on the SiC substrate 30 of the SiC composite substrate 10, and heat treatment and grinding are performed in this order, so that the SiC substrate 30 as the second layer can be provided on the SiC substrate 30. can.
- Example 1 Preparation of Orientation Precursor Layer 90.8% by weight of commercially available fine ⁇ -SiC powder (volume-based D50 particle size: 0.7 ⁇ m) and yttrium oxide powder (volume-based D50 particle size: 0.1 ⁇ m)8.
- Raw material powder containing 1% by weight and 1.1% by weight of silicon dioxide powder (volume-based D50 particle size: 0.7 ⁇ m) is mixed by ball mill mixing for 24 hours in ethanol using SiC balls and drying. A powder was obtained.
- a commercially available SiC single crystal substrate n-type 4H—SiC, diameter 100 mm (4 inches), Si plane, (0001) plane, off angle 4°, thickness 0.35 mm, no orientation flat
- An AD film orientation precursor layer was formed by injecting the mixed powder onto the SiC single crystal substrate by the device 50 .
- AD film forming conditions were as follows. First, N2 was used as a carrier gas, and a film was formed using a ceramic nozzle having a slit with a long side of 5 mm and a short side of 0.4 mm.
- the nozzle scanning conditions were a scan speed of 0.5 mm/s, a movement of 105 mm in the forward direction perpendicular to the long side of the slit, a 5 mm movement in the long side of the slit, and a return perpendicular to the long side of the slit.
- the thickness of the AD film thus formed was about 400 ⁇ m.
- the (0001) plane (that is, the surface of the heat-treated layer) of the SiC composite substrate in which the heat-treated layer is formed on the SiC single crystal substrate is polished with diamond abrasive grains (particle size: 3.0 ⁇ m, 1.0 ⁇ m, 0.5 ⁇ m, and 0.1 ⁇ m) were used in descending order of particle size and polished to achieve the target thickness and surface condition.
- the (000-1) plane of the SiC composite substrate having a heat-treated layer formed on the SiC single crystal substrate is ground with a grinder (1000 to 6000 diamond wheel). It was surface-ground to a predetermined thickness. Subsequently, diamond abrasive grains (particle sizes of 3.0 ⁇ m, 1.0 ⁇ m, 0.5 ⁇ m and 0.1 ⁇ m) were used in descending order of particle size for polishing. As a result, the entire SiC single crystal substrate was ground to obtain a substrate (SiC substrate) consisting only of the heat-treated layer.
- a graph was created in which the distance ( ⁇ m) in the [11-20] direction was plotted on the horizontal axis and the PL intensity I was plotted on the vertical axis.
- the graph had a shape of repeating maxima and minima.
- the maximum point is a point that gives a higher PL intensity I than each of the six PL intensities I in total consisting of the first, second and third closest points on the left and right, and , confirm that the minimum point is a point that gives a lower PL intensity I than each of the total 6 points consisting of the 1st, 2nd and 3rd closest points on the left and right bottom. Also, from FIG.
- the maximum value of the PL intensity I at a certain maximum point PM is defined as M, and the distance in the horizontal axis direction is longer than this maximum point PM , and the local minimum at the position closest to this maximum point PM M/m was calculated, where m is the minimum value of PL intensity I at point Pm . Furthermore, the distance L in the [11-20] direction between the maximum point P M and the minimum point P m was measured. The results were as shown in Table 1. The measurement conditions at this time were as shown below. From FIG. 4, it was found that the step width of the step-terrace structure on the surface of the heat-treated layer was as wide as about 100 to 200 ⁇ m.
- image processing software (product name: WinROOF2015) was used to process 5 ⁇ 5 in the [11-20] direction. was processed by a Prewitt filter with a kernel of The results are shown in FIG.
- a line segment of 500 ⁇ m parallel to the [11-20] direction (indicated by the lower left line segment in FIG. 6) was drawn at an arbitrary position in the filtered image.
- a graph was prepared by plotting the distance ( ⁇ m) in the [11-20] direction on the horizontal axis and the PL intensity IF on the vertical axis in the line segment area. The graph is shown in FIG. This graph had a shape in which multiple maximum points were repeated.
- the maximum point is the point that gives a higher PL intensity IF than each of the total 6 PL intensity IF points consisting of the first, second and third closest points on the left and right. It was confirmed.
- a maximum point P M1 and a maximum point P M2 that is at a longer distance in the horizontal axis direction than this maximum point P M1 and that is closest to this maximum point P M1 [ 11- 20] direction distance L F was measured. The results were as shown in Table 1.
- Threading screw dislocation (TSD) density of heat-treated layer (biaxially oriented SiC layer) SiC composite substrate obtained by above (1) to (3-1) was processed into chips by above (4) Using the sample as an evaluation sample, the TSD density (cm ⁇ 2 ) of the biaxially oriented SiC layer was measured. An evaluation sample was placed in a crucible made of nickel together with a KOH crystal, and etched in an electric furnace at 500° C. for 10 minutes. After the etching treatment, the evaluation sample was washed, the surface was observed with an optical microscope, and the type of dislocation was determined from the shape of the pits.
- the TSD density was measured with a shell-shaped pit as a basal plane dislocation, a small hexagonal pit as a threading edge dislocation, and a medium or large hexagonal pit as a TSD.
- the surface of this evaluation sample is polished in the same procedure as in (3-1) above, and the etching process and TSD density measurement are repeated multiple times in the same manner as described above to obtain the TSD density at multiple depths. bottom.
- the horizontal axis represents the depth (polishing thickness) ( ⁇ m) from the (0001) plane, which is the substrate surface of the evaluation sample, to an arbitrary (000-1) plane, and the TSD density ( cm ⁇ 2 ) was plotted on the vertical axis.
- the area where the TSD density increases from the (0001) plane to the (000-1) plane (the area where the polishing thickness is about 380 to 400 ⁇ m), that is, from the (0001) plane to any (000-1)
- a region where the TSD density decreases with a constant slope a as the depth to the surface decreases is defined as a TSD gradient region.
- a TSD gradient region In this graph of the TSD gradient area, an approximate straight line was obtained by the method of least squares, and the absolute value of the gradient a of the TSD density with respect to the polishing thickness was obtained.
- the TSD density of the (0001) plane of the evaluation sample with a polishing thickness of 50 ⁇ m was regarded as the TSD density of the SiC substrate surface and measured. The results were as shown in Table 1.
- Example 2 (Comparison) A SiC substrate was produced and evaluated in the same manner as in Example 1, except that the annealing temperature was set to 2200° C. in (2) above. It was confirmed that the heat-treated layer of the obtained SiC substrate was a biaxially oriented SiC layer. The results were as shown in Table 1.
- Example 3 8. In (1) above, 85.8% by weight of fine ⁇ -SiC powder (volume-based D50 particle size: 0.7 ⁇ m) and yttrium oxide powder (volume-based D50 particle size: 0.1 ⁇ m)8. A powder containing 1% by weight, 1.1% by weight of silicon dioxide powder (volume-based D50 particle size: 0.7 ⁇ m), and 5.0% by weight of boron carbide powder (volume-based D50 particle size: 0.5 ⁇ m) was used. A SiC substrate was produced and evaluated in the same manner as in Example 1 except for the above. It was confirmed that the heat-treated layer of the obtained SiC substrate was a biaxially oriented SiC layer. The results were as shown in Table 1.
- Example 4 8. In (1) above, 80.8% by weight of fine ⁇ -SiC powder (volume-based D50 particle size: 0.7 ⁇ m) and yttrium oxide powder (volume-based D50 particle size: 0.1 ⁇ m)8. A powder containing 1% by weight, 1.1% by weight of silicon dioxide powder (volume-based D50 particle size: 0.7 ⁇ m), and 10.0% by weight of boron carbide powder (volume-based D50 particle size: 0.5 ⁇ m) was used. A SiC substrate was produced and evaluated in the same manner as in Example 1 except for the above. It was confirmed that the heat-treated layer of the obtained SiC substrate was a biaxially oriented SiC layer. The results were as shown in Table 1.
- example 5 8.
- fine ⁇ -SiC powder volume-based D50 particle size: 0.7 ⁇ m
- yttrium oxide powder volume-based D50 particle size: 0.1 ⁇ m
- a powder containing 1% by weight, 1.1% by weight of silicon dioxide powder volume-based D50 particle size: 0.7 ⁇ m
- 20.0% by weight of boron carbide powder volume-based D50 particle size: 0.5 ⁇ m
- a SiC substrate was produced and evaluated in the same manner as in Example 1 except for the above. It was confirmed that the heat-treated layer of the obtained SiC substrate was a biaxially oriented SiC layer. The results were as shown in Table 1.
- Example 6 (Comparison) 8.
- 60.8% by weight of fine ⁇ -SiC powder volume-based D50 particle size: 0.7 ⁇ m
- yttrium oxide powder volume-based D50 particle size: 0.1 ⁇ m
- a powder containing 1% by weight, 1.1% by weight of silicon dioxide powder volume-based D50 particle size: 0.7 ⁇ m
- 30.0% by weight of boron carbide powder volume-based D50 particle size: 0.5 ⁇ m
- a SiC substrate was produced and evaluated in the same manner as in Example 1 except for the above. It was confirmed that the heat-treated layer of the obtained SiC substrate was a biaxially oriented SiC layer. The results were as shown in Table 1.
- Example 7 A SiC substrate was produced and evaluated in the same manner as in Example 1, except that the annealing temperature was set to 2350° C. in (2) above. It was confirmed that the heat-treated layer of the obtained SiC substrate was a biaxially oriented SiC layer. The results were as shown in Table 1.
- the distribution of the PL intensity with respect to the distance in the [11-20] direction can be controlled by the annealing temperature and the boron content.
- the ratio of M / m is 1.05 or more and the distance L is 15 to 150 ⁇ m, or
- the distance LF is 30 to 300 ⁇ m, so that the TSD density of the (0001) plane of the evaluation sample with a polishing thickness of 50 ⁇ m, that is, biaxial orientation It was found that the TSD density on the SiC layer surface can be reduced.
- a SiC substrate provided with a biaxially oriented SiC layer having a TSD gradient region in which the TSD density is reduced in a and the absolute value of the gradient a is 5.0 cm ⁇ 2 / ⁇ m or more is the biaxially oriented SiC layer It has been found that the surface TSD density can be effectively reduced.
- the step width of the step-terrace structure on the surface of the biaxially oriented SiC layer of the SiC substrate showing an example of the present invention is as wide as about 100 to 200 ⁇ m.
- Non-Patent Document 2 (Toru Ujihara et al. “Conversion Mechanism of Threading Screw Dislocation during SiC Solution Growth” Materials Science Forum Vols. 717-720, pp. 351-354 (2012)), shown in FIG.
- the step width on the surface of the SiC substrate produced by the solution growth method is as narrow as 20 ⁇ m or less. It is considered that such a step-terrace structure difference affects the TSD density on the SiC substrate surface.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
Description
[態様1]
二軸配向SiC層を備えたSiC基板であって、前記二軸配向SiC層の表面をフォトルミネッセンス(PL)で解析して、[11-20]方向の距離(μm)を横軸とし、かつ、PL強度Iを縦軸としてプロットしたグラフを得た場合に、
(i)前記グラフが極大点及び極小点を繰り返す形状を有し、ここで、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも高いPL強度Iを与える点として定義され、かつ、極小点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも低いPL強度Iを与える点として定義され、
(ii)ある極大点PMにおけるPL強度Iの極大値をMとし、該極大点PMよりも前記横軸方向の距離が長く、かつ、該極大点PMと最も近い位置にある極小点PmにおけるPL強度Iの極小値をmとしたとき、M/mの比が1.05以上であり、
(iii)前記極大点PMと前記極小点Pmとの前記[11-20]方向の距離Lが15~150μmである、SiC基板。
[態様2]
前記距離Lが50~150μmである、態様1に記載のSiC基板。
[態様3]
二軸配向SiC層を備えたSiC基板であって、前記二軸配向SiC層の表面をフォトルミネッセンス(PL)で解析して得られた画像において、前記画像の[11-20]方向についてプレヴィットフィルタにより処理し、[11-20]方向の距離(μm)を横軸とし、かつ、PL強度IFを縦軸としてプロットしたグラフを得た場合に、
(i)前記グラフが複数の極大点を繰り返す形状を有し、ここで、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度IFの各々よりも高いPL強度IFを与える点として定義され、
(ii)ある極大点PM1と、該極大点PM1よりも前記横軸方向の距離が長く、かつ、該極大点PM1と最も近い位置にある極大点PM2との前記[11-20]方向の距離LFが30~300μmである、SiC基板。
[態様4]
前記二軸配向SiC層が、c軸方向及びa軸方向に配向しており、前記二軸配向SiC層に対して、基板表面である(0001)面から任意の(000-1)面までの深さ(μm)を横軸とし、かつ、貫通らせん転位(TSD)密度(cm-2)を縦軸としてプロットしたグラフを得た場合に、前記グラフが、前記深さが減少するにつれて一定の傾きaで前記TSD密度が減少し、かつ、前記傾きaの絶対値が5.0cm-2/μm以上となるTSD傾斜領域を含む、態様1~3のいずれか一つに記載のSiC基板。
[態様5]
前記二軸配向SiC層が、ホウ素を1.0×1016~1.0×1017atoms/cm3の濃度で含む、態様1~4のいずれか一つに記載のSiC基板。
[態様6]
前記傾きaの絶対値が5.0~25cm-2/μmである、態様4に記載のSiC基板。
[態様7]
SiC単結晶基板と、前記SiC単結晶基板上の態様1~6のいずれか一つに記載のSiC基板とを備えた、SiC複合基板。
本発明によるSiC基板は、二軸配向SiC層を備えたSiC基板である。この二軸配向SiC層は、その表面をフォトルミネッセンス(PL)で解析して、[11-20]方向の距離(μm)を横軸とし、かつ、PL強度Iを縦軸としてプロットしたグラフを得た場合に、例えば後述する図5に示されるように、(i)極大点及び極小点を繰り返す特有の形状を有するものである。ここで、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも高いPL強度Iを与える点として定義され、かつ、極小点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも低いPL強度Iを与える点として定義される。そして、このグラフは、以下の条件:
(ii)ある極大点PMにおけるPL強度Iの極大値をMとし、その極大点PMよりも横軸方向の距離が長く、かつ、その極大点PMと最も近い位置にある極小点PmにおけるPL強度Iの極小値をmとしたとき、M/mの比が1.05以上であること、及び
(iii)上記極大点PMと上記極小点Pmとの[11-20]方向の距離Lが15~150μmであること
を満たすものである。あるいは、二軸配向SiC層は、その表面をPLで解析して得られた画像において、その画像の[11-20]方向についてプレヴィット(Prewitt)フィルタにより処理し、[11-20]方向の距離(μm)を横軸とし、かつ、PL強度IFを縦軸としてプロットしたグラフを得た場合に、例えば後述する図7に示されるように、(iv)複数の極大点を繰り返す形状を有するものである。ここで、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度IFの各々よりも高いPL強度IFを与える点として定義される。そして、このグラフは、以下の条件:
(v)ある極大点PM1と、その極大点PM1よりも横軸方向の距離が長く、かつ、その極大点PM1と最も近い位置にある極大点PM2との[11-20]方向の距離LFが30~300μmであること
を満たすものである。
本発明のSiC基板は、SiC基板のみからなる自立基板であってもよいし、SiC複合基板の形態でもあってもよい。SiC複合基板は、SiC単結晶基板と、SiC単結晶基板上の上述したSiC基板とを備えたものでありうる。
本発明のSiC基板を備えるSiC複合基板は、(a)SiC単結晶基板上に所定の配向前駆体層を形成し、(b)SiC単結晶基板上で配向前駆体層を熱処理してその少なくともSiC単結晶基板近くの部分をSiC基板(二軸配向SiC層)に変換し、所望により(c)研削や研磨等の加工を施して二軸配向SiC層の表面を露出させることにより好ましく製造することができる。しかしながら、SiC複合基板の製造方法には限定がなく、二軸配向SiC層を備えたSiC基板をPLにより解析した場合に、上述したような特定の解析結果となるSiC基板を得ることができればよい。例えば、製造方法としては、CVDや昇華法のような気相法でもよいし、溶液法のような液相法でもよいし、粒成長を利用した固相法でもよい。PLにより得られたグラフにおけるPL強度の分布は、上記(b)の熱処理条件を制御することや、上記(a)の配向前駆体層形成の際に、ホウ素又はホウ素化合物(例えば炭化ホウ素等)の添加量を制御すること等により、制御することができる。このような製造方法によれば、二軸配向SiC層を備えたSiC基板をPLにより解析した場合に、上述したような特定の解析結果となるSiC基板を作製することができ、SiC基板ないしそれを用いたSiC複合基板の表面のTSD密度を有意に低減することができる。
図2(a)に示すように、配向前駆体層40は、後述の熱処理によりSiC基板(二軸配向SiC層)30となるものである。配向前駆体層40の形成工程では、SiC単結晶基板20の結晶成長面に配向前駆体層40を形成する。
図2(b)に示すように、熱処理工程では、SiC単結晶基板20上に配向前駆体層40が積層又は載置された積層体を熱処理することによりSiC基板30を生成させる。熱処理方法は、SiC単結晶基板20を種としたエピタキシャル成長が生じるかぎり特に限定されず、管状炉やホットプレート等、公知の熱処理炉で実施することができる。また、これらの常圧(プレスレス)での熱処理だけでなく、ホットプレスやHIP等の加圧熱処理や、常圧熱処理と加圧熱処理の組み合わせも用いることができる。熱処理の雰囲気は真空、窒素、及び不活性ガス雰囲気から選択することができる。熱処理温度は、好ましくは1700~2700℃である。温度を高くすることで、SiC単結晶基板20を種結晶として配向前駆体層40がc軸及びa軸に配向しながら成長しやすくなる。したがって、熱処理温度は、好ましくは1700℃以上、より好ましくは1850℃以上、さらに好ましくは2000℃以上、特に好ましくは2200℃以上である。一方、温度が過度に高いと、SiCの一部が昇華により失われたり、SiCが塑性変形して反り等の不具合が生じたりする可能性がある。したがって、熱処理温度は、好ましくは2700℃以下、より好ましくは2500℃以下である。しかしながら、熱処理条件は、二軸配向SiC層表面のPLにより得られたグラフにおけるPL強度の分布に影響を与えるため、その条件(例えば熱処理温度や保持時間)を適宜制御するのが好ましい。このような観点から、熱処理温度は、好ましくは2000~2700℃、より好ましくは2200~2600℃、さらに好ましくは2400~2500℃である。また、その保持時間は2~30時間が好ましく、より好ましくは4~20時間である。また、熱処理温度や保持時間はエピタキシャル成長で生じるSiC基板30の厚さにも関係しており、適宜調整できる。
図2(c)に示すように、研削及び研磨工程では、熱処理工程後にSiC基板30上に残った配向前駆体層40を研削除去して、SiC基板30の表面を露出させ、露出した表面をダイヤモンド砥粒を用いて研磨加工し、所望によりCMP(化学機械研磨)仕上げを行う。こうすることにより、SiC複合基板10を得る。なお、SiC複合基板10のSiC単結晶基板20を除去したい場合は、例えばグラインダで所定の厚さまで平面研削し、次いでダイヤモンド砥粒を用いて研磨加工してもよい。
(1)配向前駆体層の作製
市販の微細β-SiC粉末(体積基準D50粒径:0.7μm)を90.8重量%、酸化イットリウム粉末(体積基準D50粒径:0.1μm)8.1重量%、二酸化ケイ素粉末(体積基準D50粒径:0.7μm)1.1重量%を含む原料粉体を、SiCボールを使用してエタノール中で24時間ボールミル混合し、乾燥することで混合粉末を得た。市販のSiC単結晶基板(n型4H-SiC、直径100mm(4インチ)、Si面、(0001)面、オフ角4°、厚み0.35mm、オリフラなし)を用意し、図3に示すAD装置50によりSiC単結晶基板上に混合粉末を噴射してAD膜(配向前駆体層)を形成した。
配向前駆体層であるAD膜を形成したSiC単結晶基板をAD装置から取り出し、アルゴン雰囲気中で2400℃にて10時間アニールした。すなわち、配向前駆体層を熱処理して熱処理層とした。こうして、SiC単結晶基板上に熱処理層を形成したSiC複合基板を作製した。
(3-1)表面研磨
SiC単結晶基板上に熱処理層を形成したSiC複合基板の(0001)面(すなわち、熱処理層表面)を、ダイヤモンド砥粒(粒度3.0μm、1.0μm、0.5μm及び0.1μmのもの)を粒度が大きい順に用いて研磨加工し、目標の厚さ及び面状態にした。
上記(3-1)の後、SiC単結晶基板上に熱処理層を形成したSiC複合基板の(000-1)面を、グラインダ(1000~6000番手のダイヤモンドホイール)で所定の厚さまで平面研削した。続いてダイヤモンド砥粒(粒度3.0μm、1.0μm、0.5μm及び0.1μmのもの)を粒度が大きい順に用いて研磨加工した。これにより、SiC単結晶基板を全て研削し、熱処理層のみから成る基板(SiC基板)を得た。
試料として、上記(3-1)又は(3-2)で得た、SiC複合基板又はSiC基板をダイヤモンドカッターで切断し、5mm×6mmのチップ状に加工した。
(5-1)熱処理層の二軸配向性
EBSD(Electron Back Scatter Diffraction Patterns)法を用いて、以下に示す条件により、上記(3-1)及び(3-2)にて作製した熱処理層の表面(板面)及び板面と直交する断面の逆極点図マッピングを測定したところ、傾斜角度分布は略法線方向及び略板面方向ともに0.01°以下であったため、熱処理層はc軸とa軸に配向した二軸配向SiC層であると判断した。
・加速電圧:15kv
・スポット強度:70
・ワーキングディスタンス:22.5mm
・ステップサイズ:0.5μm
・試料傾斜角:70°
・測定プログラム:Aztec(version 3.3)
上記(1)~(4)にて作製した熱処理層(二軸配向SiC層)をチップ状に加工した試料を評価サンプルとし、評価サンプル表面のPLイメージング像を取得した。このとき、図4に示すように、取得したPLイメージング像において任意の3.0mm×2.2mmの領域を切り出した。この領域の任意の位置に、[11-20]方向に平行な500μmの線分(図4では左下の線分で示した部分)を引いた。図5に示すように、その線分領域において、[11-20]方向の距離(μm)を横軸に、PL強度Iを縦軸にプロットしたグラフを作成した。このグラフは極大点及び極小点を繰り返す形状を有していた。そして、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも高いPL強度Iを与える点であり、かつ、極小点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも低いPL強度Iを与える点であることを確認した。また、この図5より、ある極大点PMにおけるPL強度Iの極大値をMとし、この極大点PMよりも横軸方向の距離が長く、この極大点PMと最も近い位置にある極小点PmにおけるPL強度Iの極小値をmとしたときの、M/mを算出した。さらに、極大点PMと極小点Pmとの[11-20]方向の距離Lを測定した。結果は表1に示されるとおりであった。このときの測定条件は以下に示すとおりであった。なお、図4より、熱処理層表面のステップ-テラス構造はステップ幅が100~200μm程度と広いことが分かった。
・励起波長:313nm
・検出波長:750nm以上
・測定温度:室温
・検出器:CCDカメラ(Roper Scientific)
上記(1)~(4)にて作製した熱処理層(二軸配向SiC層)をチップ状に加工した試料を評価サンプルとし、二次イオン質量分析法(SIMS)により二軸配向SiC層内部のホウ素濃度の定量を行った。評価サンプルの基板表面である(0001)面から10μmの深さまでのホウ素濃度を測定したところ、ホウ素濃度は二軸配向SiC層の深さによらずほぼ一定であり、そのホウ素濃度は表1に示されるとおりであった。なお、本例においては、ホウ素化合物を添加していないにも関わらず二軸配向SiC層にホウ素が検出されているが、これは不可避不純物としてのホウ素が検出されているに過ぎない。このときの分析条件は以下に示すとおりであった。
・一次イオン種:O2 +
・一次加速電圧:11.0kV
・検出領域:直径30μm
・検出深さ:10μm
上記(1)~(3-1)により得られたSiC複合基板を上記(4)によりチップ状に加工した試料を評価サンプルとして、二軸配向SiC層のTSD密度(cm-2)を測定した。ニッケル製のるつぼに、評価サンプルをKOH結晶と共に入れ、500℃で10分間、電気炉でエッチング処理を行った。エッチング処理後の評価サンプルを洗浄し、その表面を光学顕微鏡にて観察し、ピットの形状から転位の種類を判断した。ここでは、貝殻型ピットを基底面転位、小型の六角形ピットを貫通刃状転位、中型ないし大型の六角形ピットをTSDとして、TSD密度を計測した。次いで、この評価サンプルの表面に対し、上記(3-1)と同様の手順で研磨し、上記同様にエッチング処理とTSD密度の計測を複数回繰り返し行い、複数の深さでのTSD密度を取得した。こうして、図8に示すように、評価サンプルの基板表面である(0001)面から任意の(000-1)面までの深さ(研磨厚み)(μm)を横軸とし、かつ、TSD密度(cm-2)を縦軸としてプロットしたグラフを取得した。図8において(0001)面から(000-1)面にかけてTSD密度が増大している領域(研磨厚みが約380~400μmまでの領域)、すなわち、(0001)面から任意の(000-1)面までの深さが減少するにつれて一定の傾きaでTSD密度が減少している領域をTSD傾斜領域とした。このTSD傾斜領域のグラフにおいて、最小二乗法で近似直線を求め、研磨厚みに対するTSD密度の傾きaの絶対値を求めた。また、研磨厚み50μmでの評価サンプルの(0001)面のTSD密度を、SiC基板表面のTSD密度とみなして測定した。結果は表1に示されるとおりであった。
上記(2)において、アニール温度を2200℃にしたこと以外は、例1と同様にしてSiC基板の作製及び評価を行った。得られたSiC基板の熱処理層は二軸配向SiC層であることが確認された。結果は表1に示されるとおりであった。
上記(1)において、原料粉体として、微細β-SiC粉末(体積基準D50粒径:0.7μm)を85.8重量%、酸化イットリウム粉末(体積基準D50粒径:0.1μm)8.1重量%、二酸化ケイ素粉末(体積基準D50粒径:0.7μm)1.1重量%、炭化ホウ素粉末(体積基準D50粒径:0.5μm)5.0重量%を含む粉体を使用したこと以外は、例1と同様にしてSiC基板の作製及び評価を行った。得られたSiC基板の熱処理層は二軸配向SiC層であることが確認された。結果は表1に示されるとおりであった。
上記(1)において、原料粉体として、微細β-SiC粉末(体積基準D50粒径:0.7μm)を80.8重量%、酸化イットリウム粉末(体積基準D50粒径:0.1μm)8.1重量%、二酸化ケイ素粉末(体積基準D50粒径:0.7μm)1.1重量%、炭化ホウ素粉末(体積基準D50粒径:0.5μm)10.0重量%を含む粉体を使用したこと以外は、例1と同様にしてSiC基板の作製及び評価を行った。得られたSiC基板の熱処理層は二軸配向SiC層であることが確認された。結果は表1に示されるとおりであった。
上記(1)において、原料粉体として、微細β-SiC粉末(体積基準D50粒径:0.7μm)を70.8重量%、酸化イットリウム粉末(体積基準D50粒径:0.1μm)8.1重量%、二酸化ケイ素粉末(体積基準D50粒径:0.7μm)1.1重量%、炭化ホウ素粉末(体積基準D50粒径:0.5μm)20.0重量%を含む粉体を使用したこと以外は、例1と同様にしてSiC基板の作製及び評価を行った。得られたSiC基板の熱処理層は二軸配向SiC層であることが確認された。結果は表1に示されるとおりであった。
上記(1)において、原料粉体として、微細β-SiC粉末(体積基準D50粒径:0.7μm)を60.8重量%、酸化イットリウム粉末(体積基準D50粒径:0.1μm)8.1重量%、二酸化ケイ素粉末(体積基準D50粒径:0.7μm)1.1重量%、炭化ホウ素粉末(体積基準D50粒径:0.5μm)30.0重量%を含む粉体を使用したこと以外は、例1と同様にしてSiC基板の作製及び評価を行った。得られたSiC基板の熱処理層は二軸配向SiC層であることが確認された。結果は表1に示されるとおりであった。
上記(2)において、アニール温度を2350℃にしたこと以外は、例1と同様にしてSiC基板の作製及び評価を行った。得られたSiC基板の熱処理層は二軸配向SiC層であることが確認された。結果は表1に示されるとおりであった。
Claims (7)
- 二軸配向SiC層を備えたSiC基板であって、前記二軸配向SiC層の表面をフォトルミネッセンス(PL)で解析して、[11-20]方向の距離(μm)を横軸とし、かつ、PL強度Iを縦軸としてプロットしたグラフを得た場合に、
(i)前記グラフが極大点及び極小点を繰り返す形状を有し、ここで、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも高いPL強度Iを与える点として定義され、かつ、極小点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度Iの各々よりも低いPL強度Iを与える点として定義され、
(ii)ある極大点PMにおけるPL強度Iの極大値をMとし、該極大点PMよりも前記横軸方向の距離が長く、かつ、該極大点PMと最も近い位置にある極小点PmにおけるPL強度Iの極小値をmとしたとき、M/mの比が1.05以上であり、
(iii)前記極大点PMと前記極小点Pmとの前記[11-20]方向の距離Lが15~150μmである、SiC基板。 - 前記距離Lが50~150μmである、請求項1に記載のSiC基板。
- 二軸配向SiC層を備えたSiC基板であって、前記二軸配向SiC層の表面をフォトルミネッセンス(PL)で解析して得られた画像において、前記画像の[11-20]方向についてプレヴィットフィルタにより処理し、[11-20]方向の距離(μm)を横軸とし、かつ、PL強度IFを縦軸としてプロットしたグラフを得た場合に、
(i)前記グラフが複数の極大点を繰り返す形状を有し、ここで、極大点は、その左右における1番目に近い点、2番目に近い点及び3番目に近い点からなる合計6点のPL強度IFの各々よりも高いPL強度IFを与える点として定義され、
(ii)ある極大点PM1と、該極大点PM1よりも前記横軸方向の距離が長く、かつ、該極大点PM1と最も近い位置にある極大点PM2との前記[11-20]方向の距離LFが30~300μmである、SiC基板。 - 前記二軸配向SiC層が、c軸方向及びa軸方向に配向しており、前記二軸配向SiC層に対して、基板表面である(0001)面から任意の(000-1)面までの深さ(μm)を横軸とし、かつ、貫通らせん転位(TSD)密度(cm-2)を縦軸としてプロットしたグラフを得た場合に、前記グラフが、前記深さが減少するにつれて一定の傾きaで前記TSD密度が減少し、かつ、前記傾きaの絶対値が5.0cm-2/μm以上となるTSD傾斜領域を含む、請求項1又は3に記載のSiC基板。
- 前記二軸配向SiC層が、ホウ素を1.0×1016~1.0×1017atoms/cm3の濃度で含む、請求項1又は3に記載のSiC基板。
- 前記傾きaの絶対値が5.0~25cm-2/μmである、請求項4に記載のSiC基板。
- SiC単結晶基板と、前記SiC単結晶基板上の請求項1又は3に記載のSiC基板とを備えた、SiC複合基板。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2023514848A JPWO2023068309A1 (ja) | 2021-10-22 | 2022-10-19 | |
CN202280043244.0A CN117529584A (zh) | 2021-10-22 | 2022-10-19 | SiC基板和SiC复合基板 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021039155 | 2021-10-22 | ||
JPPCT/JP2021/039155 | 2021-10-22 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US18/441,303 Continuation US20240186380A1 (en) | 2021-10-22 | 2024-02-14 | SiC SUBSTRATE SiC COMPOSITE SUBSTRATE |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023068309A1 true WO2023068309A1 (ja) | 2023-04-27 |
Family
ID=86058268
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/039004 WO2023068309A1 (ja) | 2021-10-22 | 2022-10-19 | SiC基板及びSiC複合基板 |
Country Status (3)
Country | Link |
---|---|
JP (1) | JPWO2023068309A1 (ja) |
CN (1) | CN117529584A (ja) |
WO (1) | WO2023068309A1 (ja) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11228295A (ja) * | 1998-02-04 | 1999-08-24 | Nippon Pillar Packing Co Ltd | 単結晶SiC及びその製造方法 |
JP2004533720A (ja) * | 2001-05-11 | 2004-11-04 | クリー インコーポレイテッド | 高い降伏電圧を有する半導体デバイスのための高抵抗率炭化珪素基板 |
JP2014043369A (ja) | 2012-08-26 | 2014-03-13 | Nagoya Univ | SiC単結晶の製造方法およびSiC単結晶 |
-
2022
- 2022-10-19 WO PCT/JP2022/039004 patent/WO2023068309A1/ja active Application Filing
- 2022-10-19 JP JP2023514848A patent/JPWO2023068309A1/ja active Pending
- 2022-10-19 CN CN202280043244.0A patent/CN117529584A/zh active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11228295A (ja) * | 1998-02-04 | 1999-08-24 | Nippon Pillar Packing Co Ltd | 単結晶SiC及びその製造方法 |
JP2004533720A (ja) * | 2001-05-11 | 2004-11-04 | クリー インコーポレイテッド | 高い降伏電圧を有する半導体デバイスのための高抵抗率炭化珪素基板 |
JP2014043369A (ja) | 2012-08-26 | 2014-03-13 | Nagoya Univ | SiC単結晶の製造方法およびSiC単結晶 |
Non-Patent Citations (2)
Title |
---|
LIXIA ZHAO ET AL.: "Surface defects in 4H-SiC homoepitaxial layers", NANOTECHNOLOGY AND PRECISION ENGINEERING, vol. 3, 2020, pages 229 - 234 |
TORU UJIHARA ET AL.: "Conversion Mechanism of Threading Screw Dislocation during SiC Solution Growth", MATERIALS SCIENCE FORUM, vol. 717-720, 2012, pages 351 - 354 |
Also Published As
Publication number | Publication date |
---|---|
CN117529584A (zh) | 2024-02-06 |
JPWO2023068309A1 (ja) | 2023-04-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20220278206A1 (en) | BIAXIALLY ORIENTED SiC COMPOSITE SUBSTRATE AND SEMICONDUCTOR DEVICE COMPOSITE SUBSTRATE | |
JP7282214B2 (ja) | 希土類含有SiC基板及びSiCエピタキシャル層の製法 | |
US20210301422A1 (en) | SiC COMPOSITE SUBSTRATE AND SEMICONDUCTOR DEVICE | |
US20210384145A1 (en) | SiC COMPOSITE SUBSTRATE AND COMPOSITE SUBSTRATE FOR SEMICONDUCTOR DEVICE | |
US20210404090A1 (en) | Ground substrate and method for producing same | |
JP7410009B2 (ja) | 半導体膜 | |
WO2023068309A1 (ja) | SiC基板及びSiC複合基板 | |
US20210384300A1 (en) | SiC COMPOSITE SUBSTRATE AND COMPOSITE SUBSTRATE FOR SEMICONDUCTOR DEVICE | |
US20240186380A1 (en) | SiC SUBSTRATE SiC COMPOSITE SUBSTRATE | |
WO2021100564A1 (ja) | SiC基板及びその製法 | |
WO2023062850A1 (ja) | 希土類含有SiC基板及びSiC複合基板 | |
WO2024042591A1 (ja) | SiC基板及びSiC複合基板 | |
WO2022168372A1 (ja) | 希土類含有SiC基板及びそれを用いたSiC複合基板 | |
JP7104266B1 (ja) | 希土類含有SiC基板及びSiC複合基板 | |
WO2022201986A1 (ja) | AlN単結晶基板 | |
JP7124207B2 (ja) | 下地基板 | |
JP7265624B2 (ja) | 半導体膜 | |
JP7320070B2 (ja) | 下地基板及びその製造方法 | |
JP7439117B2 (ja) | 下地基板及びその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 2023514848 Country of ref document: JP |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22883613 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202280043244.0 Country of ref document: CN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2022883613 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2022883613 Country of ref document: EP Effective date: 20240522 |