WO2011065122A9 - 半導体基板の製造方法 - Google Patents
半導体基板の製造方法 Download PDFInfo
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- WO2011065122A9 WO2011065122A9 PCT/JP2010/066827 JP2010066827W WO2011065122A9 WO 2011065122 A9 WO2011065122 A9 WO 2011065122A9 JP 2010066827 W JP2010066827 W JP 2010066827W WO 2011065122 A9 WO2011065122 A9 WO 2011065122A9
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- semiconductor substrate
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- silicon carbide
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Images
Classifications
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- 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
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/324—Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
-
- 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
-
- 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
-
- 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
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/67005—Apparatus not specifically provided for elsewhere
- H01L21/67011—Apparatus for manufacture or treatment
- H01L21/67098—Apparatus for thermal treatment
- H01L21/67109—Apparatus for thermal treatment mainly by convection
-
- 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
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/67005—Apparatus not specifically provided for elsewhere
- H01L21/67011—Apparatus for manufacture or treatment
- H01L21/67098—Apparatus for thermal treatment
- H01L21/67115—Apparatus for thermal treatment mainly by radiation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/16—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only elements of Group IV of the Periodic Table
- H01L29/1608—Silicon carbide
Definitions
- the present invention relates to a method for manufacturing a semiconductor substrate, and more particularly to a method for manufacturing a semiconductor substrate including a silicon carbide substrate.
- SiC substrates are being adopted as semiconductor substrates used in the manufacture of semiconductor devices.
- SiC has a larger band gap than Si (silicon) which is more commonly used. Therefore, a semiconductor device using a SiC substrate has advantages such as high breakdown voltage, low on-resistance, and small deterioration in characteristics under a high temperature environment.
- Patent Document 1 a SiC substrate of 76 mm (3 inches) or more can be manufactured.
- the size of the SiC substrate is industrially limited to about 100 mm (4 inches), and therefore there is a problem that a semiconductor device cannot be efficiently manufactured using a large substrate.
- the above-described problem becomes particularly serious when the characteristics of a plane other than the (0001) plane are used. This will be described below.
- a SiC substrate with few defects is usually manufactured by cutting out from an SiC ingot obtained by (0001) plane growth in which stacking faults are unlikely to occur. For this reason, the SiC substrate having a plane orientation other than the (0001) plane is cut out non-parallel to the growth plane. For this reason, it is difficult to ensure a sufficient size of the substrate, or many portions of the ingot cannot be used effectively. For this reason, it is particularly difficult to efficiently manufacture a semiconductor device using a surface other than the (0001) surface of SiC.
- this semiconductor substrate a gap is formed between adjacent SiC substrates.
- foreign matter tends to accumulate during the manufacturing process of the semiconductor device using this semiconductor substrate.
- This foreign material is, for example, a cleaning liquid or an abrasive used in the manufacturing process of the semiconductor device, or dust in the atmosphere.
- Such foreign matters cause a decrease in manufacturing yield, and as a result, there is a problem in that the manufacturing efficiency of the semiconductor device decreases.
- the present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a semiconductor substrate that is large in size and capable of manufacturing a semiconductor device with a high yield.
- the manufacturing method of the semiconductor substrate of this invention has the following processes.
- a plurality of silicon carbide substrates having first and second silicon carbide substrates and a support portion are prepared.
- the first silicon carbide substrate includes a first back surface facing the support portion and located on one plane, a first surface facing the first back surface, a first back surface, and a first surface. And a first side surface to be connected.
- the second silicon carbide substrate has a second back surface facing the support portion and located on one plane, a second surface facing the second back surface, a second back surface, and a second surface. And a second side to be connected.
- the second side surface is arranged such that a gap having an opening between the first and second surfaces is formed between the first side surface and the second side surface.
- the support portion and the first and second silicon carbide substrates are heated so that a joint that closes the opening is formed.
- the process of heating has the following processes.
- the temperature of the first radiation surface facing the plurality of silicon carbide substrates in the first space extending from the plurality of silicon carbide substrates in a direction perpendicular to one plane and away from the support portion is the first temperature. Is done.
- the temperature of the second radiation surface facing the support portion is higher than the first temperature. 2 temperature.
- the temperature of the third radiation surface facing the plurality of silicon carbide substrates is set to a third temperature lower than the second temperature.
- the temperature of the third radiation surface facing the plurality of silicon carbide substrates in the third space is the third temperature lower than the second temperature, from the third radiation surface. Therefore, the disturbance of the temperature gradient along the gap caused by the temperature difference between the first and second radiation surfaces due to the heat radiation from the third radiation surface is reduced. As a result, the temperature gradient is more reliably formed, so that a sublimation that closes the opening of the gap can be generated more reliably. That is, the opening of the gap of the semiconductor substrate obtained by this manufacturing method is more reliably closed.
- the semiconductor substrate can be easily enlarged by increasing the number of the plurality of silicon carbide substrates. Therefore, a semiconductor substrate that is large and capable of manufacturing a semiconductor device with a high yield can be obtained.
- the third temperature is set lower than the first temperature.
- the influence of the heat radiation from the third radiation surface to the gap is smaller than the heat radiation from the first radiation surface having the first temperature. Therefore, the disturbance of the temperature gradient due to heat radiation from the third radiation surface can be further reduced.
- the step of preparing the plurality of silicon carbide substrates and the support portion is performed by preparing a composite substrate having the support portion and the first and second silicon carbide substrates. Each of the back surfaces of 2 is joined to the support part.
- the above manufacturing method further includes a step of bonding each of the first and second back surfaces to the support portion.
- the step of bonding each of the first and second back surfaces is performed simultaneously with the step of forming the bonding portion.
- the support portion is made of silicon carbide.
- the manufacturing method further includes a step of depositing a sublimate from the support portion on the joint portion in a gap having an opening blocked by the joint portion.
- the step of depositing the sublimate from the support part on the joint part is performed so as to move the entire gap having the opening closed by the joint part into the support part.
- the heating step is performed by a heat source arranged outside the third space.
- the heat source is disposed in a space including the support portion among the spaces separated from each other by the third space.
- the thermal conductivity of the material forming the third radiating surface is lower than the thermal conductivity of the material forming the second radiating surface.
- the thermal conductivity of the material forming the third radiating surface is lower than the thermal conductivity of the material forming the first radiating surface.
- the heating step is performed by first to third heating elements arranged in each of the first to third spaces.
- the first to third heating elements are controlled independently of each other.
- the method for manufacturing a semiconductor substrate further includes a step of polishing each of the first and second surfaces.
- the first and second surfaces as the surface of the semiconductor substrate can be flat surfaces, so that a high-quality film can be formed on the flat surface of the semiconductor substrate.
- each of the first and second back surfaces is a surface formed by slicing. That is, each of the first and second back surfaces is a surface formed by slicing and not polished thereafter. This provides relief on each of the first and second back surfaces. Therefore, the space in the concave and convex portions can be used as a gap in which the sublimation gas spreads when the support portion is provided on the first and second back surfaces by the sublimation method.
- the heating step is performed in an atmosphere having a pressure higher than 10 ⁇ 1 Pa and lower than 10 4 Pa.
- FIG. 2 is a schematic sectional view taken along line II-II in FIG. It is a top view which shows roughly the 1st process of the manufacturing method of the semiconductor substrate in Embodiment 1 of this invention.
- FIG. 4 is a schematic sectional view taken along line IV-IV in FIG. 3. It is sectional drawing which shows schematically the 2nd process of the manufacturing method of the semiconductor substrate in Embodiment 1 of this invention.
- FIG. 6 is a partially enlarged view of FIG. 5. It is a schematic diagram for demonstrating the mode of the thermal radiation in the manufacturing method of the semiconductor substrate in Embodiment 1 of this invention.
- FIG. 18 is a schematic sectional view taken along line XVIII-XVIII in FIG. It is a top view which shows roughly the structure of the semiconductor substrate in Embodiment 5 of this invention.
- FIG. 20 is a schematic sectional view taken along line XX-XX in FIG. 19. It is sectional drawing which shows roughly 1 process of the manufacturing method of the semiconductor substrate in Embodiment 6 of this invention. It is sectional drawing which shows roughly 1 process of the manufacturing method of the semiconductor substrate in Embodiment 7 of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the semiconductor substrate of the comparative example of Embodiment 7 of this invention. It is sectional drawing which shows roughly 1 process of the manufacturing method of the semiconductor substrate in Embodiment 8 of this invention. It is sectional drawing which shows roughly 1 process of the manufacturing method of the semiconductor substrate in Embodiment 9 of this invention.
- the semiconductor substrate 80 a of the present embodiment has a support portion 30 and a supported portion 10 a supported by the support portion 30.
- Supported portion 10a includes SiC substrates 11 to 19 (silicon carbide substrate).
- the support part 30 connects the back surfaces of the SiC substrates 11 to 19 (the surface opposite to the surface shown in FIG. 1) to each other, whereby the SiC substrates 11 to 19 are fixed to each other.
- Each of SiC substrates 11 to 19 has a surface exposed on the same plane.
- each of SiC substrates 11 and 12 has first and second surfaces F1 and F2 (FIG. 2).
- semiconductor substrate 80a has a larger surface than each of SiC substrates 11-19. Therefore, the semiconductor device can be manufactured more efficiently when the semiconductor substrate 80a is used than when each of the SiC substrates 11 to 19 is used alone.
- the support portion 30 is preferably made of a material that can withstand a temperature of 1800 ° C. or higher, and is made of, for example, silicon carbide, carbon, or a high melting point metal.
- the refractory metal include molybdenum, tantalum, tungsten, niobium, iridium, ruthenium, and zirconium. If silicon carbide is used as the material of support portion 30, the physical properties of support portion 30 can be made closer to SiC substrates 11 to 19.
- a gap VDa exists between the SiC substrates 11 to 19, and the surface side (upper side in FIG. 2) of the gap VDa is closed by the joint portion BDa.
- the joint portion BDa includes a portion located between the first and second surfaces F1 and F2, thereby smoothly connecting the first and second surfaces F1 and F2.
- Composite substrate 80P includes support portion 30 and SiC substrate group 10 (a plurality of silicon carbide substrates).
- SiC substrate group 10 includes SiC substrate 11 (first silicon carbide substrate) and SiC substrate 12 (second silicon carbide substrate).
- SiC substrate 11 faces support portion 30 and is located on first plane PL1 (one plane), and is located on first plane PL1 and on second plane PL2 that faces first back face B1. And a first side surface S1 that connects the first back surface B1 and the first surface F1.
- the first back surface B ⁇ b> 1 is joined to the support portion 30.
- SiC substrate 12 faces support portion 30 and is located on first plane PL1, and second back surface B2 is opposite to second back surface B2 and is located on second plane PL2.
- 2 surface F2 and 2nd side surface S2 which connects 2nd back surface B2 and 2nd surface F2.
- the second back surface B ⁇ b> 2 is joined to the support portion 30.
- the second side surface S2 is arranged such that a gap GP having an opening CR between the first and second surfaces F1, F2 is formed between the first side surface S1.
- the heating device includes a heat insulating container 40, a heater (heat source) 50, first and second heating bodies 91 a and 92, and a heater power supply 150.
- the heat insulating container 40 is formed from a material having high heat insulating properties.
- the heater 50 is, for example, an electric resistance heater.
- the first and second heating bodies have a function of absorbing radiant heat from the heater 50 and radiating the heat obtained thereby to the composite substrate 80P. That is, the first and second heating bodies 91a and 92 have a function of heating the composite substrate 80P.
- the 1st and 2nd heating bodies 91a and 92 are formed from the graphite with a small porosity, for example.
- the first heating body 91a, the composite substrate 80P, and the second heating body 92 are housed in the heat insulating container 40 in which the heater 50 is disposed. These positional relationships will be described below.
- the composite substrate 80P is arranged on the heating body 91a so that the SiC substrate group 10 faces the first radiation surface RP1 of the first heating body 91a.
- the first space SP1 (FIG. 7) extending from the SiC substrate group 10 in a direction perpendicular to the first plane PL1 and away from the support portion 30, the first radiation surface is formed on the SiC substrate group 10.
- RP1 faces.
- the second radiation surface RP2 of the second heating body 92 is disposed on the composite substrate 80P so as to face the support portion 30.
- Each of the first and second heating bodies 91a and 92 is disposed outside the third space SP3 (FIG. 7) extending from the gap GP along the first plane PL1.
- the support portion 30 is provided with the second radiation surface RP2. Faces.
- the heater 50 is disposed outside the third space SP3 (FIG. 7) extending from the gap GP along the first plane PL1, and more specifically, the space 50 separated from each other by the third space.
- the support portion 30 is disposed (the space above the first plane PL1 in FIG. 5).
- radiation surface RP3 of heat insulation container 40 faces SiC substrate group 10 in 3rd space SP3 (Drawing 7).
- the support unit 30 and the SiC substrates 11 and 12 are heated by the heater 50. This heating step will be described below.
- the atmosphere in the heat insulating container 40 is an atmosphere obtained by depressurizing the air atmosphere.
- the pressure of the atmosphere is preferably higher than 10 ⁇ 1 Pa and lower than 10 4 Pa.
- the above atmosphere may be an inert gas atmosphere.
- the inert gas for example, a rare gas such as He or Ar, a nitrogen gas, or a mixed gas of a rare gas and a nitrogen gas can be used.
- the ratio of nitrogen gas is, for example, 60%.
- the pressure in the processing chamber is preferably 50 kPa or less, and more preferably 10 kPa or less.
- the respective temperatures of the first radiation surface RP1 of the first heating body 91a, the second radiation surface RP2 of the second heating body RP2, and the third radiation surface RP3 of the heat insulating container 40 are the first The first to third temperatures are set.
- the second temperature is set higher than the first temperature.
- the third temperature is lower than the second temperature, and preferably lower than the first temperature.
- the temperature of second side ICb which is the side facing support portion 30 of SiC substrate group 10 is changed to SiC substrate group 10. It becomes higher than the temperature of the first side ICt that is the side facing the first heating body 91a. That is, a temperature gradient is generated in the thickness direction of SiC substrate group 10 (vertical direction in FIG. 8). Due to this temperature gradient, the first side ICt from the surface of the SiC substrates 11 and 12, that is, the first and second side surfaces S1 and S2, in the gap GP, from a relatively high temperature region close to the second side ICb. As shown by the arrows in the figure, sublimates are generated and moved to a relatively low temperature region close to.
- the sublimate forms a junction BDa that closes the opening CR so as to connect the side surfaces S1 and S2.
- the gap GP (FIG. 8) becomes the gap VDa (FIG. 9) closed by the joint portion BDa.
- the setting temperature of the heater 50 was fixed at 2000 ° C., and the atmospheric pressure during the above heating was examined.
- the joint BDa was not formed at 100 kPa, and the joint BDa was difficult to be formed at 50 kPa, but this problem was seen at 10 kPa, 100 Pa, 1 Pa, 0.1 Pa, and 0.0001 Pa. There wasn't.
- FIG. 10 a case will be described where it is assumed that a part of the heater 50 is located in the space between the first and second planes PL1 and PL2.
- at least a part of the third radiation surface RP3 (FIG. 7) is not the heat insulating container 40 but the heater 50.
- the temperature of at least a part of the third radiation surface RP3 becomes higher than the temperature of the second radiation surface RP2
- strong heat radiation is performed from the third radiation surface RP3 to the gap GP. Due to the influence of this strong heat radiation, the temperature gradient between the first and second sides ICt and ICb in the gap GP is disturbed.
- the movement of the sublimate (arrows in FIGS. 8 and 9) is disturbed, so that the joint portion BDa is not formed or takes time to form. That is, in the comparative example, the opening CR is difficult to close.
- the temperature (third temperature) of the third radiation surface RP3 (FIG. 7) is lower than the temperature (second temperature) of the second radiation surface RP2.
- the influence of heat radiation from the third radiation surface RP3 to the gap GP is weaker than that of heat radiation from the second radiation surface RP2. Therefore, the disturbance due to the thermal radiation from the third radiation surface RP3 of the temperature gradient along the gap GP caused by the temperature difference between the first and second radiation surfaces RP1 and RP2 is reduced. As a result, the temperature gradient is more reliably generated, so that the joint portion BDa formed by the sublimation that closes the opening CR of the gap can be more reliably formed.
- the opening of the gap VDa of the semiconductor substrate 80a (FIGS. 1 and 2) obtained by the present manufacturing method is more reliably closed by the bonding portion BDa. Therefore, in the manufacturing process of the semiconductor device using the semiconductor substrate 80a, foreign matter is unlikely to accumulate in the gap VDa, and thus a decrease in yield due to the foreign matter is suppressed.
- the semiconductor substrate 80a (FIG. 2) includes both the first and second surfaces F1 and F2 of the SiC substrate as substrate surfaces on which semiconductor devices such as transistors are formed.
- semiconductor substrate 80a has a larger substrate surface than when either SiC substrate 11 or 12 is used alone. Therefore, a semiconductor device can be efficiently manufactured with the semiconductor substrate 80a.
- SiC substrate group 10 is arranged on first heating body 91a.
- a flexibility such as a graphite sheet is provided between SiC substrate group 10 and first heating body 91a.
- a protective film such as a resist film may be formed in advance on the first and second surfaces F1 and F2.
- a protective film such as a resist film may be formed in advance on the first and second surfaces F1 and F2.
- Embodiment 2 a method of manufacturing composite substrate 80P (FIGS. 3 and 4) used in Embodiment 1 will be described in detail particularly when support portion 30 is made of silicon carbide.
- SiC substrates 11 and 12 among SiC substrates 11 to 19 may be referred to, but SiC substrates 13 to 19 are also referred to as SiC substrates 11 and 12, respectively. Treated similarly.
- SiC substrates 11 and 12 having a single crystal structure are prepared. Specifically, for example, SiC substrates 11 and 12 are prepared by cutting a SiC ingot grown on the (0001) plane in the hexagonal system along the (03-38) plane. Preferably, the roughness of the back surfaces B1 and B2 is 100 ⁇ m or less as Ra.
- SiC substrates 11 and 12 are arranged on first heating body 81 in the processing chamber so that each of back surfaces B1 and B2 is exposed in one direction (upward direction in FIG. 11). That is, SiC substrates 11 and 12 are arranged so as to be aligned in plan view.
- the above arrangement is performed such that each of the back surfaces B1 and B2 is located on the same plane, or each of the first and second surfaces F1 and F2 is located on the same plane.
- the shortest distance between SiC substrates 11 and 12 is 5 mm or less, more preferably 1 mm or less, still more preferably 100 ⁇ m or less, and even more preferably 10 ⁇ m or less. It is said.
- substrates having the same rectangular shape are arranged in a matrix with an interval of 1 mm or less.
- the support part 30 (FIG. 4) which connects the back surfaces B1 and B2 to each other is formed as follows.
- each of the back surfaces B1 and B2 exposed in one direction (upward direction in FIG. 11), and the surface SS of the solid raw material 20 arranged in one direction (upward direction in FIG. 11) with respect to the back surfaces B1 and B2. are opposed to each other with a gap D1.
- the average value of the distance D1 is 1 ⁇ m or more and 1 cm or less.
- the solid material 20 is made of SiC, preferably a lump of silicon carbide solid material, specifically, for example, a SiC wafer.
- the crystal structure of SiC of the solid raw material 20 is not particularly limited.
- the roughness of the surface SS of the solid raw material 20 is 1 mm or less as Ra.
- the spacer 83 (FIG. 14) which has the height corresponding to the space
- SiC substrates 11 and 12 are heated to a predetermined substrate temperature by first heating body 81. Further, the solid raw material 20 is heated to a predetermined raw material temperature by the second heating body 82. When the solid raw material 20 is heated to the raw material temperature, SiC is sublimated on the surface SS of the solid raw material, thereby generating a sublimate, that is, a gas. This gas is supplied onto each of the back surfaces B1 and B2 from one direction (the upward direction in FIG. 11).
- the substrate temperature is lower than the raw material temperature, and more preferably the difference between the two temperatures is 1 ° C. or higher and 100 ° C. or lower.
- the substrate temperature is 1800 ° C. or higher and 2500 ° C. or lower.
- the gas supplied as described above is recrystallized by being solidified on each of back surfaces B1 and B2.
- the support part 30p which connects back surface B1 and B2 mutually is formed.
- the solid raw material 20 (FIG. 11) becomes the solid raw material 20p by being consumed and becoming small.
- the solid raw material 20p (FIG. 12) disappears due to further sublimation. Thereby, the support part 30 which connects back surface B1 and B2 mutually is formed.
- the atmosphere in the processing chamber is an inert gas.
- the inert gas for example, a rare gas such as He or Ar, a nitrogen gas, or a mixed gas of a rare gas and a nitrogen gas can be used.
- the ratio of nitrogen gas is, for example, 60%.
- the pressure in the processing chamber is preferably 50 kPa or less, and more preferably 10 kPa or less.
- the support 30 has a single crystal structure. More preferably, the inclination of the crystal face of the support part 30 on the back face B1 with respect to the crystal face of the back face B1 is within 10 °, and the crystal face of the support part 30 on the back face B2 with respect to the crystal face of the back face B2 The inclination of is within 10 °.
- the crystal structures of the SiC substrates 11 and 12 are preferably hexagonal, and more preferably 4H—SiC or 6H—SiC.
- SiC substrates 11 and 12 and support portion 30 are preferably made of a SiC single crystal having the same crystal structure.
- the concentrations of SiC substrates 11 and 12 and the impurity concentration of support portion 30 are different from each other. More preferably, the impurity concentration of support portion 30 is higher than the impurity concentration of each of SiC substrates 11 and 12.
- the impurity concentration of SiC substrates 11 and 12 is, for example, not less than 5 ⁇ 10 16 cm ⁇ 3 and not more than 5 ⁇ 10 19 cm ⁇ 3 .
- the impurity concentration of the support portion 30 is, for example, 5 ⁇ 10 16 cm ⁇ 3 or more and 5 ⁇ 10 21 cm ⁇ 3 or less.
- nitrogen or phosphorus can be used, for example.
- the off angle of first surface F1 with respect to ⁇ 0001 ⁇ plane of SiC substrate 11 is not less than 50 ° and not more than 65 °, and the off angle of second surface F2 with respect to ⁇ 0001 ⁇ plane of SiC substrate is 50. It is not less than 65 ° and not more than 65 °.
- the angle formed between the off orientation of first surface F1 and the ⁇ 1-100> direction of SiC substrate 11 is 5 ° or less, and the off orientation of second surface F2 and ⁇ 1-100 of substrate 12 The angle formed by the 100> direction is 5 ° or less.
- the off angle of the first surface F1 with respect to the ⁇ 03-38 ⁇ plane in the ⁇ 1-100> direction of the SiC substrate 11 is not less than ⁇ 3 ° and not more than 5 °.
- the off angle of the second surface F2 with respect to the ⁇ 03-38 ⁇ plane in the direction is not less than ⁇ 3 ° and not more than 5 °.
- the “off angle of the first surface F1 with respect to the ⁇ 03-38 ⁇ plane in the ⁇ 1-100> direction” refers to the first projection plane extending in the ⁇ 1-100> direction and the ⁇ 0001> direction.
- the case where the orthographic projection approaches parallel to the ⁇ 0001> direction is negative.
- the angle formed between the off orientation of the first surface F1 and the ⁇ 11-20> direction of the substrate 11 is 5 ° or less, and the off orientation of the second surface F2 and the ⁇ 11-20 of the substrate 12 The angle formed with the> direction is 5 ° or less.
- support portion 30 formed on each of back surfaces B1 and B2 is made of SiC in the same manner as SiC substrates 11 and 12, so that various physical properties are present between SiC substrate and support portion 30. Get closer. Therefore, warpage and cracking of the composite substrate 80P (FIGS. 3 and 4) or the semiconductor substrate 80a (FIGS. 1 and 2) due to the difference in physical properties can be suppressed.
- the support part 30 can be formed with high quality and at high speed. Moreover, the support part 30 can be formed more uniformly because the sublimation method is a proximity sublimation method.
- the film thickness distribution of the support portion 30 can be reduced.
- the average value of the distance D1 (FIG. 11) between each of the back surfaces B1 and B2 and the surface of the solid raw material 20
- the temperature of SiC substrates 11 and 12 is set lower than the temperature of solid raw material 20 (FIG. 11). Thereby, the sublimated SiC can be efficiently solidified on SiC substrates 11 and 12.
- the step of arranging SiC substrates 11 and 12 is performed such that the shortest distance between SiC substrates 11 and 12 is 1 mm or less.
- support part 30 can be formed so as to connect back surface B1 of SiC substrate 11 and back surface B2 of SiC substrate 12 more reliably.
- the support 30 has a single crystal structure. Thereby, various physical properties of support portion 30 can be brought close to various physical properties of SiC substrates 11 and 12 having a single crystal structure.
- the inclination of the crystal plane of the support portion 30 on the back surface B1 is within 10 ° with respect to the crystal surface of the back surface B1.
- the inclination of the crystal plane of the support portion 30 on the back surface B2 is within 10 ° with respect to the crystal surface of the back surface B2.
- the impurity concentrations of SiC substrates 11 and 12 and the impurity concentration of support portion 30 are different from each other.
- a semiconductor substrate 80a (FIG. 2) having a two-layer structure with different impurity concentrations can be obtained.
- the impurity concentration of support portion 30 is higher than the impurity concentration of each of SiC substrates 11 and 12. Therefore, the resistivity of support portion 30 can be reduced as compared with the resistivity of each of SiC substrates 11 and 12. As a result, a semiconductor substrate 80a suitable for manufacturing a semiconductor device in which a current flows in the thickness direction of the support portion 30, that is, a vertical semiconductor device, can be obtained.
- the off angle of first surface F1 with respect to ⁇ 0001 ⁇ plane of SiC substrate 11 is not less than 50 ° and not more than 65 °
- the off angle of second surface F2 with respect to ⁇ 0001 ⁇ plane of SiC substrate 12 is It is 50 degrees or more and 65 degrees or less.
- the channel mobility in the 1st and 2nd surfaces F1 and F2 can be raised compared with the case where the 1st and 2nd surfaces F1 and F2 are ⁇ 0001 ⁇ planes.
- the angle formed between the off orientation of first surface F1 and the ⁇ 1-100> direction of SiC substrate 11 is 5 ° or less, and the off orientation of second surface F2 and ⁇ 1 of SiC substrate 12
- the angle made with the ⁇ 100> direction is 5 ° or less.
- the off angle of the first surface F1 with respect to the ⁇ 03-38 ⁇ plane in the ⁇ 1-100> direction of the SiC substrate 11 is not less than ⁇ 3 ° and not more than 5 °.
- the off angle of the second surface F2 with respect to the ⁇ 03-38 ⁇ plane in the direction is not less than ⁇ 3 ° and not more than 5 °.
- the angle formed between the off orientation of first surface F1 and the ⁇ 11-20> direction of SiC substrate 11 is 5 ° or less, and the off orientation of second surface F2 and ⁇ 11 of SiC substrate 12
- the angle formed with the -20> direction is 5 ° or less.
- the SiC wafer is exemplified as the solid raw material 20, but the solid raw material 20 is not limited to this, and may be, for example, SiC powder or SiC sintered body.
- the first and second heating bodies 81 and 82 may be any one that can heat the object.
- a resistance heating type using a graphite heater, or an induction heating type. can be used.
- a space is provided between each of the back surfaces B1 and B2 and the surface SS of the solid raw material 20 throughout.
- a space may be provided between each of the back surfaces B1 and B2 and the surface SS of the solid material 20 while the back surfaces B1 and B2 and the surface SS of the solid material 20 are in partial contact. Two modifications corresponding to this case will be described below.
- the above interval is ensured by the warp of the SiC wafer as the solid material 20. More specifically, in this example, the interval D2 is locally zero, but the average value always exceeds zero. Further, preferably, the average value of the distance D2 is 1 ⁇ m or more and 1 cm or less, similarly to the average value of the distance D1.
- the above-mentioned interval is ensured by warping of SiC substrates 11-13. More specifically, in this example, the interval D3 is locally zero, but the average value always exceeds zero. In addition, preferably, the average value of the distance D3 is 1 ⁇ m or more and 1 cm or less, similarly to the average value of the distance D1.
- the interval may be ensured by a combination of the methods shown in FIGS. 15 and 16, that is, both the warp of the SiC wafer as the solid material 20 and the warp of the SiC substrates 11 to 13.
- the back surfaces (for example, back surfaces B1 and B2) of SiC substrates 11 to 13 are surfaces formed by slicing, that is, surfaces formed by slicing and not polished thereafter. Also good. This provides relief on each back surface. Therefore, the space in the undulating concave portion can be used for securing the above-mentioned distance.
- each of the first and second back surfaces B1 and B2 is joined to the support portion 30 in advance by, for example, the method of the second embodiment. .
- first and second back surfaces B1 and B2 are joined to the support portions 30 simultaneously with the formation of the joint portion BDa. That is, in the present embodiment, after the step of preparing support portion 30 and SiC substrate group 10, the step of bonding each of first and second back surfaces B ⁇ b> 1 and B ⁇ b> 2 of SiC substrate group 10 to support portion 30. The step of joining is performed simultaneously with the step of forming the joint portion BDa (FIG. 2).
- the step of bonding each of the first and second back surfaces B1 and B2 to the support portion 30 is performed simultaneously with the step of forming the bonding portion BDa. Therefore, the manufacturing process of the semiconductor substrate 80a (FIGS. 1 and 2) can be simplified as compared with the case where both processes are performed separately.
- solid raw material 20 (FIG. 11) is prepared instead of support portion 30 (FIG. 5) as a support portion prepared before heating, and solid raw material 20 and SiC substrate group 10 are May be arranged in the same manner as in the second embodiment, and the heater 50 may be arranged in the same manner as in the first embodiment.
- the configuration of FIG. 15, the configuration of FIG. 16, or a combination thereof may be used.
- support portion 30 is made of SiC, and mass transfer associated with sublimation is continued even after bonding portion BDa is formed as shown in FIG.
- sublimation from the support portion 30 into the closed gap VDa occurs to the extent that it cannot be ignored. That is, the sublimate from the support part 30 is deposited on the joint part BDa.
- gap VDa between SiC substrates 11 and 12 moves so as to partially penetrate into support portion 30, resulting in gap VDb (FIG. 18) closed by bonding portion BDb.
- a thick junction BDb can be formed as compared with the junction BDa of the semiconductor substrate 80a (FIG. 2).
- semiconductor substrate 80 c of the present embodiment has a gap closed by joint BDc instead of gap VDb (FIG. 18: Embodiment 4) closed by joint BDb. VDc.
- the semiconductor substrate 80c is obtained by moving the entire gap VDa (FIG. 2) into the support portion 30 via the position of the gap VDb (FIG. 18) by the same method as in the fourth embodiment.
- a thicker joint BDc can be formed as compared with the joint BDb of the fourth embodiment.
- the gap VDc may be moved until it reaches the back surface side (the lower side in FIG. 20). Thereby, the closed gap VDc becomes a recess on the back surface side. Further, the recess may be removed by polishing.
- heat insulator 93 is arranged to face SiC substrate group 10 in the third space (FIG. 7). That is, instead of the heat insulating container 40, the heat insulating body 93 forms the third radiation surface RP3.
- the thermal conductivity of the heat insulator 93 is lower than that of the second heating body 92, that is, the material forming the second radiation surface RP2, and is preferably the same as that of the first heating body 91a (FIG. 5). It is made lower than the thermal conductivity of the first heating body 91b formed of the material, that is, the material forming the first radiation surface RP1.
- Such a heat insulator 93 is made of, for example, carbon felt.
- the temperature of the third radiation surface RP3 can be more reliably lowered by the heat insulator 93.
- the degree of freedom in arranging the heater 50 is higher than that in the first embodiment.
- the heating device of the present embodiment is an induction heating furnace, and has a heated body 59 (heat source) and a coil 159 instead of heater 50 (FIG. 5).
- the heated body 59 is, for example, a graphite crucible, and forms a substantially closed space in the heat insulating container 40. In this closed space, first heating body 91a, second heating body 92, SiC substrate group 10, and support portion 30 are arranged. Further, as in the sixth embodiment, a heat insulator 93 is arranged.
- the heated body 59 generates heat by induction heating by the coil 159.
- the first heating body 91a and the second heating body 92 are heated.
- the same effect as in the sixth embodiment can be obtained. If the heat insulator 93 is not used, since the configuration as shown in FIG. 23, that is, the third radiation surface RP3 (FIG. 7) is configured by the heated body 59, FIG. 10 (Embodiment 1) As in the case of the configuration of Comparative Example), the opening CR (FIG. 8) is difficult to close.
- heat radiation is generated in the configuration shown in FIG. 7 as in the first embodiment, so that the same effect as in the first embodiment can be obtained.
- the heating apparatus of the present embodiment performs heating by using first to third heaters 51 to 53 (first to third heating elements) and first to third heaters.
- Each of the first to third heaters 51 to 53 is arranged in the first to third spaces SP1 to SP3 (FIG. 7). Note that the entire third heater 53 does not have to be arranged in the third space SP3, and at least a part of the third heater 53 may be arranged.
- Each of the first to third heater power sources 151 to 153 is connected so that the heat generation of the first to third heaters 51 to 53 can be controlled independently of each other.
- surfaces corresponding to the first to third radiation surfaces RP1 to RP3 (FIG. 7), that is, the surface of the first heating body 91a, the surface of the second heating body 92,
- the temperature of the surface of the third heater 53 can be controlled independently of each other. Therefore, the temperature corresponding to the third radiation surface RP3 can be made lower than the temperature corresponding to the second radiation surface RP2, and not too low.
- either or both of the first heater 51 and the third heater 53 may be omitted.
- a plurality of silicon carbide substrates having first and second silicon carbide substrates and a support portion are prepared.
- the first silicon carbide substrate includes a first back surface facing the support portion and located on one plane, a first surface facing the first back surface, a first back surface, and a first surface. And a first side surface to be connected.
- the second silicon carbide substrate has a second back surface facing the support portion and located on one plane, a second surface facing the second back surface, a second back surface, and a second surface. And a second side to be connected.
- the second side surface is arranged such that a gap having an opening between the first and second surfaces is formed between the first side surface and the second side surface.
- the support portion and the first and second silicon carbide substrates are heated so that a joint portion that closes the opening is formed.
- the process of heating has the following processes.
- the temperature of the first radiation surface facing the plurality of silicon carbide substrates in the first space extending from the plurality of silicon carbide substrates in a direction perpendicular to one plane and away from the support portion is the first temperature. Is done.
- the temperature of the second radiation surface facing the support portion is higher than the first temperature. 2 temperature.
- the temperature of the third radiation surface facing the plurality of silicon carbide substrates is set to a third temperature lower than the second temperature.
- the method for manufacturing a semiconductor substrate of the present invention can be particularly advantageously applied to a method for manufacturing a semiconductor substrate including a silicon carbide substrate.
- 10 SiC substrate group multiple silicon carbide substrates
- 10a supported layer 11 SiC substrate (first silicon carbide substrate), 12 SiC substrate (second silicon carbide substrate), 13-19 SiC substrate, 20, 20p Solid raw material, 30, 30p support, 40 heat insulating container, 59 heated body, 80a to 80c semiconductor substrate, 80P composite substrate, 81, 91a, 91b first heating body, 82, 92 second heating body, 93 heat insulation Body, 150 heater power supply, 151 to 153, first to third heater power supply, 159 coil.
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Abstract
Description
第1および第2の炭化珪素基板を有する複数の炭化珪素基板と支持部とが準備される。第1の炭化珪素基板は、支持部に面しかつ一の平面上に位置する第1の裏面と、第1の裏面に対向する第1の表面と、第1の裏面および第1の表面をつなぐ第1の側面とを有する。第2の炭化珪素基板は、支持部に面しかつ一の平面上に位置する第2の裏面と、第2の裏面に対向する第2の表面と、第2の裏面および第2の表面をつなぐ第2の側面とを有する。第2の側面は、第1および第2の表面の間に開口を有する隙間が第1の側面との間に形成されるように配置されている。第1および第2の側面から昇華物を発生させることで、開口を塞ぐ接合部が形成されるように、支持部と第1および第2の炭化珪素基板とが加熱される。加熱する工程は、以下の工程を有する。一の平面に垂直な方向であってかつ支持部から遠ざかる方向へ複数の炭化珪素基板から延びる第1の空間において複数の炭化珪素基板に面する第1の放射面の温度が第1の温度とされる。一の平面に垂直な方向であってかつ複数の炭化珪素基板から遠ざかる方向へ支持部から延びる第2の空間において支持部に面する第2の放射面の温度が第1の温度よりも高い第2の温度とされる。一の平面に沿って隙間から延びる第3の空間において複数の炭化珪素基板に面する第3の放射面の温度が第2の温度よりも低い第3の温度とされる。
好ましくは、上記の製造方法は、接合部によって塞がれた開口を有する隙間内において、支持部からの昇華物を接合部上に堆積させる工程をさらに備える。
好ましくは、熱源は、第3の空間によって互いに隔てられた空間のうち支持部を含む方の中に配置される。
好ましくは、第3の放射面をなす材料の熱伝導率は、第2の放射面をなす材料の熱伝導率よりも低い。
好ましくは、第3の放射面をなす材料の熱伝導率は、第1の放射面をなす材料の熱伝導率よりも低い。
好ましくは、上記の半導体基板の製造方法は、第1および第2の表面の各々を研磨する工程をさらに有する。これにより、半導体基板の表面としての第1および第2の表面を平坦な面とすることができるので、半導体基板のこの平坦な面上に高品質の膜を形成することができる。
好ましくは、第1および第2の裏面の各々は、スライスによって形成された面である。すなわち第1および第2の裏面の各々は、スライスによって形成され、その後に研磨されていない面である。これにより第1および第2の裏面の各々の上に起伏が設けられる。よってこの起伏の凹部内の空間を、第1および第2の裏面上に支持部を昇華法によって設ける場合において、昇華ガスが広がる空隙として用いることができる。
(実施の形態1)
図1および図2を参照して、本実施の形態の半導体基板80aは、支持部30と、支持部30によって支持された被支持部10aとを有する。被支持部10aは、SiC基板11~19(炭化珪素基板)を有する。
次に本実施の形態の半導体基板80aの製造方法について説明する。なお以下において説明を簡略化するためにSiC基板11~19のうちSiC基板11および12に関してのみ言及する場合があるが、SiC基板13~19もSiC基板11および12と同様に扱われる。
RP2と、断熱容器40の第3の放射面RP3とのそれぞれの温度が、第1~第3の温度とされる。第2の温度は第1の温度よりも高くされる。また第3の温度は第2の温度よりも低くされ、好ましくは、第1の温度よりも低くされる。
本実施の形態においては、実施の形態1で用いられる複合基板80P(図3、図4)の製造方法について、特に支持部30が炭化珪素からなる場合について詳しく説明する。なお以下において説明を簡略化するためにSiC基板11~19(図3、図4)のうちSiC基板11および12に関してのみ言及する場合があるが、SiC基板13~19もSiC基板11および12と同様に扱われる。
また上記間隔の確保のために、SiC基板11~13の各々の裏面(たとえば裏面B1およびB2)が、スライスによって形成された面、すなわちスライスによって形成され、その後に研磨されていない面とされてもよい。これにより各裏面上に起伏が設けられる。よってこの起伏の凹部内の空間を上記間隔の確保のために用いることができる。
実施の形態1においては、接合部BDa(図2)を形成する前に、たとえば実施の形態2の方法によって、第1および第2の裏面B1、B2の各々が支持部30に予め接合される。
図17および図18を参照して、本実施の形態の半導体基板80bは、接合部BDaによって閉塞された隙間VDa(図2:実施の形態1~3)の代わりに、接合部BDbによって閉塞された隙間VDbを有する。
本実施の形態においては、支持部30はSiCからなり、かつ図9に示すように接合部BDaが形成された後も、さらに昇華にともなう物質移動が続けられる。この結果、閉塞された隙間VDa内への支持部30からの昇華も無視できない程度発生する。すなわち支持部30からの昇華物が接合部BDa上に堆積する。これによりSiC基板11および12の間の隙間VDaが支持部30内に一部侵入するように移動して、接合部BDbによって閉塞された隙間VDb(図18)となる。
図19および図20を参照して、本実施の形態の半導体基板80cは、接合部BDbによって閉塞された隙間VDb(図18:実施の形態4)の代わりに、接合部BDcによって閉塞された隙間VDcを有する。半導体基板80cは、実施の形態4と同様の方法によって、隙間VDa(図2)の全体を、隙間VDb(図18)の位置を経て、支持部30内へと移動させることによって得られる。
主に図21を参照して、本実施の形態においては、断熱体93が、第3の空間(図7)内においてSiC基板群10に面するように配置される。すなわち、断熱容器40の代わりに、断熱体93が第3の放射面RP3をなす。断熱体93の熱伝導率は、第2の加熱体92、すなわち第2の放射面RP2をなす材料の熱伝導率よりも低く、好ましくは、第1の加熱体91a(図5)と同様の材料から形成された第1の加熱体91b、すなわち第1の放射面RP1をなす材料の熱伝導率よりも低くされる。このような断熱体93は、たとえばカーボンフェルトから形成される。
図22を参照して、本実施の形態の加熱装置は誘導加熱炉であり、ヒータ50(図5)の代わりに、被加熱体59(熱源)と、コイル159とを有する。被加熱体59は、たとえばグラファイト坩堝であり、断熱容器40内に、ほぼ閉塞された空間を形成する。この閉塞された空間の中に、第1の加熱体91a、第2の加熱体92、SiC基板群10、および支持部30が配置される。また実施の形態6と同様に、断熱体93が配置される。
図24を参照して、本実施の形態においては、実施の形態7と異なり、被加熱体59が設けられず、第1および第2の加熱体91a、92が、直接、誘導加熱によって加熱される。
図25を参照して、本実施の形態の加熱装置は、加熱を行うために、第1~第3のヒータ51~53(第1~第3の発熱体)と、第1~第3のヒータ電源151~153とを有する。
第1~第3のヒータ電源151~153のそれぞれは、第1~第3のヒータ51~53の発熱を互いに独立して制御することができるように接続されている。これにより、本実施の形態において第1~第3の放射面RP1~RP3(図7)のそれぞれに相当する面、つまり、第1の加熱体91aの面、第2の加熱体92の面、および第3のヒータ53の面の温度を、互いに独立に制御することができる。よって第3の放射面RP3に相当する温度を、第2の放射面RP2に相当する温度よりも低くしつつ、また過度に低くはならないようにすることができる。
本発明の半導体基板は、以下の製造方法で作製されたものである。
Claims (16)
- 第1および第2の炭化珪素基板(11、12)を有する複数の炭化珪素基板(10)と支持部(30)とを準備する工程を備え、前記第1の炭化珪素基板は、前記支持部に面しかつ一の平面(PL1)上に位置する第1の裏面と、前記第1の裏面に対向する第1の表面と、前記第1の裏面および前記第1の表面をつなぐ第1の側面とを有し、前記第2の炭化珪素基板は、前記支持部に面しかつ前記一の平面上に位置する第2の裏面と、前記第2の裏面に対向する第2の表面と、前記第2の裏面および前記第2の表面をつなぐ第2の側面とを有し、前記第2の側面は、前記第1および第2の表面の間に開口を有する隙間(GP)が前記第1の側面との間に形成されるように配置され、さらに
前記第1および第2の側面から昇華物を発生させることで、前記開口を塞ぐ接合部が形成されるように、前記支持部と前記第1および第2の炭化珪素基板とを加熱する工程を備え、
前記加熱する工程は、
前記一の平面に垂直な方向であってかつ前記支持部から遠ざかる方向へ前記複数の炭化珪素基板から延びる第1の空間(SP1)において前記複数の炭化珪素基板に面する第1の放射面(RP1)の温度を第1の温度とする工程と、
前記一の平面に垂直な方向であってかつ前記複数の炭化珪素基板から遠ざかる方向へ前記支持部から延びる第2の空間(SP2)において前記支持部に面する第2の放射面(RP2)の温度を前記第1の温度よりも高い第2の温度とする工程と、
前記一の平面に沿って前記隙間から延びる第3の空間(SP3)において前記複数の炭化珪素基板に面する第3の放射面(RP3)の温度を前記第2の温度よりも低い第3の温度とする工程とを含む、半導体基板の製造方法。 - 前記第3の温度は前記第1の温度よりも低い、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記複数の炭化珪素基板と前記支持部とを準備する工程は、前記支持部と前記第1および第2の炭化珪素基板とを有する複合基板を準備することにより行われ、前記複合基板の前記第1および第2の裏面の各々は前記支持部に接合されている、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記支持部に前記第1および第2の裏面の各々を接合する工程をさらに備え、前記第1および第2の裏面の各々を接合する工程は、前記接合部を形成する工程と同時に行なわれる、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記支持部は炭化珪素からなる、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記接合部によって塞がれた前記開口を有する前記隙間内において、前記支持部からの昇華物を前記接合部上に堆積させる工程をさらに備えた、請求の範囲第5項に記載の半導体基板の製造方法。
- 前記支持部からの昇華物を前記接合部上に堆積させる工程は、前記接合部によって塞がれた前記開口を有する前記隙間の全体を前記支持部内へと移動させるように行われる、請求の範囲第6項に記載の半導体基板の製造方法。
- 前記加熱する工程は、前記第3の空間の外側に配置された熱源によって行われる、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記熱源は、前記第3の空間によって互いに隔てられた空間のうち前記支持部を含む方の中に配置される、請求の範囲第8項に記載の半導体基板の製造方法。
- 前記第3の放射面をなす材料の熱伝導率は、前記第2の放射面をなす材料の熱伝導率よりも低い、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記第3の放射面をなす材料の熱伝導率は、前記第1の放射面をなす材料の熱伝導率よりも低い、請求の範囲第10項に記載の半導体基板の製造方法。
- 前記加熱する工程は、前記第1~第3の空間のそれぞれの中に配置された第1~第3の発熱体によって行われる、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記第1~第3の発熱体は互いに独立して制御される、請求の範囲第12項に記載の半導体基板の製造方法。
- 前記第1および第2の表面(F1、F2)の各々は、研磨された面である、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記第1および第2の裏面(B1、B2)の各々は、スライスによって形成された面である、請求の範囲第1項に記載の半導体基板の製造方法。
- 前記加熱する工程は、10-1Paよりも高く104Paよりも低い圧力を有する雰囲気中で行われる、請求の範囲第1項に記載の半導体基板(80)の製造方法。
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