WO2020235315A1 - Crystal growth apparatus and crystal growth method - Google Patents

Crystal growth apparatus and crystal growth method Download PDF

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WO2020235315A1
WO2020235315A1 PCT/JP2020/018058 JP2020018058W WO2020235315A1 WO 2020235315 A1 WO2020235315 A1 WO 2020235315A1 JP 2020018058 W JP2020018058 W JP 2020018058W WO 2020235315 A1 WO2020235315 A1 WO 2020235315A1
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sic
crystal growth
crystal
type substrate
base
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PCT/JP2020/018058
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French (fr)
Japanese (ja)
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雄高 志賀
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信越半導体株式会社
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    • 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
    • C30B23/00—Single-crystal growth by condensing evaporated or sublimed materials
    • C30B23/02—Epitaxial-layer growth
    • C30B23/06—Heating of the deposition chamber, the substrate or the materials to be evaporated
    • 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

Definitions

  • the present invention relates to a crystal growth apparatus and a crystal growth method for performing bulk SiC single crystal growth for manufacturing a SiC single crystal wafer used for manufacturing a semiconductor device.
  • the sublimation method is mainly used as a method for growing a SiC single crystal for manufacturing a SiC single crystal wafer.
  • SiC single crystal growth by the sublimation method in general, as disclosed in Patent Document 1, a SiC seed crystal substrate (SiC seed substrate) is attached to a graphite base that also serves as a lid of a growth container. , And the lid is attached to the upper part of the main body of the growth container with the SiC type substrate facing inward. Further, the main body of the growth container is filled with a SiC powder raw material.
  • the SiC type substrate attached to the lid is in a state of facing the SiC powder raw material.
  • the SiC powder raw material is heated to an ultra-high temperature of 2000 ° C. or higher by using a heater provided outside the growth vessel, and an appropriate temperature gradient is provided in the growth vessel on the SiC type substrate.
  • SiC can be crystal-grown.
  • the present invention has been made to solve the above problems, and aims to improve the crystal quality of the grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base. It is an object of the present invention to propose a crystal growth apparatus and a crystal growth method capable of producing the same.
  • the present invention is a crystal growth apparatus for crystal-growing SiC on a SiC type substrate by heating and sublimating a SiC raw material by a sublimation method, and a main body accommodating the SiC raw material.
  • a crystal growth apparatus comprising a heater for heating the SiC raw material, wherein t2 / t1 is less than 5 when the thickness of the SiC type substrate is t1 and the thickness of the base is t2. provide.
  • the stress (thermal stress) due to the difference in physical properties between the SiC type substrate and the graphite base ) can be absorbed by the deformation of the base.
  • the stress and crystal defects generated in the grown SiC single crystal can be suppressed, and crystal quality can be improved.
  • the device characteristics of the device (power device or the like) formed in the SiC single crystal can be greatly improved.
  • t2 / t1 is 3 or less.
  • the stress due to the difference in physical properties between the SiC type substrate and the graphite base can be absorbed more reliably. Therefore, it is possible to more reliably suppress the occurrence of residual stress, crystal defects, and basal dislocations of the grown SiC single crystal that occur in the grown SiC single crystal.
  • the present invention provides a crystal growth method characterized by growing SiC crystals on the SiC type substrate using the above crystal growth apparatus.
  • a crystal growth apparatus capable of improving the crystal quality of a grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base.
  • a crystal growth method can be realized.
  • the present inventor first, in order to effectively absorb the stress due to the difference in physical properties between the SiC type substrate and the graphite base, what kind of method is effective. I examined whether there was. As a result, it was found that it is effective to absorb the stress by deformation of the graphite base on which the SiC type substrate is attached in order to suppress the occurrence of basal dislocation of the grown SiC single crystal.
  • the present inventor has determined that the occurrence of basal plane dislocations is within a predetermined crystal quality due to the deformation of the graphite base, specifically, the basal plane dislocation density of the grown SiC single crystal is 3,321 / cm 2.
  • the relationship between the SiC type substrate and the graphite base should be. As a result, it was found that when the thickness of the SiC type substrate is t1 and the thickness of the graphite base is t2, t2 / t1 is set to less than 5, and the above-mentioned predetermined crystal quality can be maintained. It was completed.
  • the present invention is a crystal growth apparatus for crystal-growing SiC on a SiC type substrate by heating and sublimating the SiC raw material by a sublimation method, wherein the main body accommodating the SiC raw material and the SiC type substrate are combined.
  • the crystal growth apparatus is characterized in that t2 / t1 is less than 5 when the thickness of the SiC type substrate is t1 and the thickness of the base is t2.
  • FIG. 1 shows an example of the crystal growth apparatus of the present invention.
  • the crystal growth device 1 is a crystal growth device that grows SiC (single crystal) on a SiC type substrate 4 by heating and sublimating the SiC raw material 5 by a sublimation method.
  • the crystal growth apparatus 1 is a heater 7 that heats a heat-resistant graphite growth container, a heat insulating material (fire pot) 6 surrounding the growth container, and a SiC raw material (for example, SiC powder raw material) 5 in the growth container.
  • the growth container is made of graphite, which serves as a base for attaching the SiC type substrate 4 and a graphite main body 2 capable of accommodating the SiC raw material 5, and is attached to the upper part of the main body 2 with the SiC type substrate 4 facing inward.
  • a lid 3 is provided.
  • the main body 2 has, for example, a cylindrical shape having a bottom, and the SiC raw material 5 is arranged at the bottom of the main body 2. Further, the upper part of the main body 2 is open.
  • the lid 3 has a disk shape, for example, so that the lid 3 can be attached to a stepped portion on the upper portion of the main body 2.
  • the heat insulating material (furnace) 6 may be a chamber or a quartz tube.
  • the heat insulating material 6 has a gas introduction port (not shown) on the upper portion thereof for introducing an inert gas (for example, Ar gas).
  • the inert gas from the Inactive gas supply unit is introduced into the furnace through the gas inlet and adjusts the pressure in the furnace.
  • the inert gas introduced into the furnace is discharged from a gas outlet (not shown).
  • the heater 7 is arranged outside the heat insulating material 6.
  • an RH heater resistor heater
  • an RF heater high frequency heater
  • the SiC raw material 5 has a function of heating to an ultra-high temperature of 2000 ° C. or higher.
  • t2 / t1 is less than 5, more preferably 3 or less. Is set to.
  • the lower limit of t2 / t1 is not particularly limited, but may be, for example, 0.1.
  • the thickness t2 of the lid 3 as the base of the SiC type substrate 4 is preferably 0.8 mm or more. As a result, the strength of the lid 3 can be ensured, and the function as the base of the SiC type substrate 4 can be fully exhibited.
  • the lid 3 has a disk shape having a certain thickness, but is not limited to this.
  • the lid 3 may have a disk shape in which the central portion is thinner than the end portion. That is, when the thickness of the end portion of the lid 3 is 5 times or more the thickness of the SiC type substrate 4, the central portion (base portion of the SiC type substrate 4) of the lid 3 is made thinner than the end portion.
  • t2 / t1 can be less than 5.
  • the heat insulating material 6 is provided with a hole 9 for temperature measurement, and a temperature measuring device 8 such as a pyrometer provided outside the heat insulating material 6 is used to make non-contact through the hole 9.
  • the temperature inside the growth vessel may be measurable.
  • FIG. 2 shows an example of the crystal growth method of the present invention.
  • the code of each element corresponds to the code attached to FIG.
  • step S1 the main body of the growth container is filled with the SiC powder material as the SiC raw material (SiC solid material) 5.
  • step S2 the SiC type substrate 4 is attached to the lid (base portion) 3 of the growth container.
  • the ratio (t2 / t1) of the thickness t1 of the SiC type substrate 4 to the thickness t2 of the base of the SiC type substrate 4 is set to less than 5, more preferably 3 or less.
  • the lid 3 is attached to the upper part of the main body 2 of the growth container with the SiC type substrate 4 facing inward.
  • the growth container is set in the heat insulating material 6 as a chamber. After that, for example, an inert gas such as Ar gas is introduced into the chamber while vacuum exhausting the inside of the chamber to create an inert gas atmosphere having a predetermined pressure in the chamber.
  • an inert gas such as Ar gas is introduced into the chamber while vacuum exhausting the inside of the chamber to create an inert gas atmosphere having a predetermined pressure in the chamber.
  • step S5 the SiC raw material 5 is heated by the heater 7, the growth container is heated to a temperature of 2000 ° C. or higher, and the growth vessel is further grown by the temperature measuring device 8 through the hole 9 for temperature measurement.
  • the SiC raw material 5 is sublimated while adjusting the temperature.
  • step S6 a SiC crystal (single crystal) grows on the SiC type substrate 4.
  • the stress due to the difference in physical properties between the SiC type substrate and the graphite base (Thermal stress) can be absorbed by the deformation of the base.
  • Thermal stress due to the difference in physical properties between the SiC type substrate and the graphite base
  • crystal quality can be improved.
  • the device characteristics of the device (power device or the like) formed in the SiC single crystal can be greatly improved.
  • the SiC single crystal was grown using the crystal growth apparatus of FIG. 1 and the crystal growth method of FIG. 2, and it was verified how much dislocation of the basal plane of the grown SiC single crystal occurred.
  • the diameter of the SiC type substrate was set to 4 inches (about 10 cm).
  • FIG. 3 shows a crystal growth apparatus of a comparative example.
  • the same elements as those of the crystal growth apparatus 1 of FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.
  • Example 1 Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 1 mm t2, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
  • Example 2 Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 2 mm, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
  • Example 3 Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 3 mm t2, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
  • Example 4 Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 4 mm t2, and the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
  • a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 5 mm t2, and after the lid is incorporated into the main body of the growth vessel.
  • SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
  • Example 1 (inspection result) -In Example 1, the average value of the dislocation density of the basal plane was 965 / cm 2 . -In Example 2, the average value of the dislocation density of the basal plane was 980 / cm 2 . -In Example 3, the average value of the dislocation density of the basal plane was 1096 / cm 2 . -In Example 4, the average value of the basal plane dislocation density was 1971 / cm 2 . -In the comparative example, the average value of the dislocation density of the basal plane was 3321 / cm 2 .
  • FIG. 4 shows the relationship between t2 / t1 and the basal dislocation density. This relationship summarizes the results of Examples 1 to 4 and Comparative Examples.
  • the basal dislocation density of the basal plane increases sharply. Therefore, it was confirmed that by setting t2 / t1 to less than 5, the basal dislocation density of the SiC wafer can be set to less than 3,321 / cm 2 , and the crystal quality of the SiC wafer can be improved.
  • the crystal quality of the SiC wafer can be further improved because the basal dislocation density of the SiC wafer can be set to 1,096 / cm 2 or less by setting t2 / t1 to 3 or less.
  • a crystal capable of improving the crystal quality of a grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base.
  • a growth apparatus and a crystal growth method can be realized.
  • the present invention is not limited to the above embodiment.
  • the above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Abstract

The present invention pertains to a crystal growth apparatus for growing a SiC crystal on a SiC seed substrate by a sublimation method wherein a SiC starting material is sublimated by heating, said apparatus comprising: a main body which houses the SiC starting material; a growth container which is made of graphite and provided with a lid body, said lid body also serving as a base for bonding the SiC seed substrate thereto and being attached to the upper part of the main body with the SiC seed substrate facing inward; a heat insulating material surrounding the growth container; and a heater heating the SiC starting material, characterized in that the ratio t2/t1 (wherein t1 stands for the thickness of the SiC seed substrate and t2 stands for the thickness of the base) is less than 5. Thus, provided is a crystal growth apparatus wherein a stress caused by a difference in properties between the SiC seed substrate and the graphite base is absorbed so that the crystalline qualities of the SiC single crystal thus grown can be improved.

Description

結晶成長装置及び結晶成長方法Crystal growth device and crystal growth method
　本発明は、半導体デバイスの製造に用いられる、ＳｉＣ単結晶ウェーハを製造するためのバルクＳｉＣ単結晶成長を行う結晶成長装置及び結晶成長方法に関する。 The present invention relates to a crystal growth apparatus and a crystal growth method for performing bulk SiC single crystal growth for manufacturing a SiC single crystal wafer used for manufacturing a semiconductor device.
　ＳｉＣ単結晶ウェーハを用いたパワーデバイスは、高耐圧、低損失、及び高温動作が可能である、といった特徴を有する事から、近年注目を集めている。 Power devices using SiC single crystal wafers have been attracting attention in recent years because they have features such as high withstand voltage, low loss, and high temperature operation.
　ＳｉＣ単結晶ウェーハを製造するためのＳｉＣ単結晶の成長方法としては、主に昇華法が用いられている。昇華法によるＳｉＣ単結晶成長では、一般的には、特許文献１に開示されるように、ＳｉＣの種結晶基板（ＳｉＣ種基板）を成長容器の蓋体を兼ねたグラファイト製の土台に貼り付け、かつ該蓋体を該ＳｉＣ種基板が内側を向いた状態で成長容器の本体の上部に取り付ける。また、成長容器の本体内には、ＳｉＣ粉末原料が充填される。 The sublimation method is mainly used as a method for growing a SiC single crystal for manufacturing a SiC single crystal wafer. In SiC single crystal growth by the sublimation method, in general, as disclosed in Patent Document 1, a SiC seed crystal substrate (SiC seed substrate) is attached to a graphite base that also serves as a lid of a growth container. , And the lid is attached to the upper part of the main body of the growth container with the SiC type substrate facing inward. Further, the main body of the growth container is filled with a SiC powder raw material.
　その結果、成長容器内において、蓋体に貼り付けられたＳｉＣ種基板は、ＳｉＣ粉末原料と対向した状態になる。この状態で、成長容器の外部に設けられたヒータを用いて、ＳｉＣ粉末原料を２０００℃以上の超高温に加熱し、かつ適切な温度勾配を成長容器中に設けることで、ＳｉＣ種基板上にＳｉＣを結晶成長させることができる。 As a result, in the growth container, the SiC type substrate attached to the lid is in a state of facing the SiC powder raw material. In this state, the SiC powder raw material is heated to an ultra-high temperature of 2000 ° C. or higher by using a heater provided outside the growth vessel, and an appropriate temperature gradient is provided in the growth vessel on the SiC type substrate. SiC can be crystal-grown.
　しかし、特許文献１に開示されるような結晶成長装置を用いた場合、ＳｉＣ種基板とその土台となるグラファイト材料との物性差のために、成長したＳｉＣ単結晶中に残留応力や結晶欠陥が生じてしまい、これらが結晶品質を劣化させる要因となっていた。特に、残留応力については、これが原因となって基底面転位が発生するが、該基底面転位は、デバイス特性を大きく劣化させることから非常に問題となる。 However, when a crystal growth apparatus as disclosed in Patent Document 1 is used, residual stress and crystal defects are generated in the grown SiC single crystal due to the difference in physical properties between the SiC type substrate and the graphite material as the base thereof. These have been factors that deteriorate the crystal quality. In particular, with regard to residual stress, basal plane dislocations occur due to this, but the basal plane dislocations are very problematic because they greatly deteriorate the device characteristics.
特開２０１８－１４０８８４号公報JP-A-2018-140884
　本発明は、上記問題を解決するためになされたものであり、ＳｉＣ種基板とグラファイト製の土台との物性差による応力を吸収することで、成長したＳｉＣ単結晶の結晶品質の向上を図ることができる結晶成長装置及び結晶成長方法を提案することを目的とする。 The present invention has been made to solve the above problems, and aims to improve the crystal quality of the grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base. It is an object of the present invention to propose a crystal growth apparatus and a crystal growth method capable of producing the same.
　上記目的を達成するために、本発明では、昇華法によりＳｉＣ原料を加熱して昇華させることでＳｉＣ種基板上にＳｉＣを結晶成長させる結晶成長装置であって、前記ＳｉＣ原料を収容する本体と、前記ＳｉＣ種基板を貼り付ける土台を兼ねるとともに前記ＳｉＣ種基板が内側を向いた状態で前記本体の上部に取り付けられる蓋体とからなるグラファイト製の成長容器と、前記成長容器を取り囲む断熱材と、前記ＳｉＣ原料を加熱するヒータとを備え、前記ＳｉＣ種基板の厚みをｔ１とし、前記土台の厚みをｔ２とした場合に、ｔ２／ｔ１が５未満であることを特徴とする結晶成長装置を提供する。 In order to achieve the above object, the present invention is a crystal growth apparatus for crystal-growing SiC on a SiC type substrate by heating and sublimating a SiC raw material by a sublimation method, and a main body accommodating the SiC raw material. A growth container made of graphite, which also serves as a base for attaching the SiC type substrate and is a lid attached to the upper part of the main body with the SiC type substrate facing inward, and a heat insulating material surrounding the growth container. A crystal growth apparatus comprising a heater for heating the SiC raw material, wherein t2 / t1 is less than 5 when the thickness of the SiC type substrate is t1 and the thickness of the base is t2. provide.
　このような結晶成長装置によれば、ｔ２（土台の厚み）／ｔ１（ＳｉＣ種基板の厚み）を５未満とすることで、ＳｉＣ種基板とグラファイト製の土台との物性差による応力（熱応力）を該土台の変形により吸収することができる。その結果、成長したＳｉＣ単結晶中に発生する残留応力や結晶欠陥を抑制でき、結晶品質の向上を図ることができる。特に、成長したＳｉＣ単結晶の基底面転位の発生を抑制できることから、該ＳｉＣ単結晶中に形成されるデバイス（パワーデバイスなど）のデバイス特性を大きく向上できる。 According to such a crystal growth apparatus, by setting t2 (thickness of the base) / t1 (thickness of the SiC type substrate) to less than 5, the stress (thermal stress) due to the difference in physical properties between the SiC type substrate and the graphite base ) Can be absorbed by the deformation of the base. As a result, residual stress and crystal defects generated in the grown SiC single crystal can be suppressed, and crystal quality can be improved. In particular, since the occurrence of basal dislocations of the grown SiC single crystal can be suppressed, the device characteristics of the device (power device or the like) formed in the SiC single crystal can be greatly improved.
　前記ｔ２／ｔ１が３以下であることが更に好ましい。 It is more preferable that t2 / t1 is 3 or less.
　これにより、ＳｉＣ種基板とグラファイト製の土台との物性差による応力をより確実に吸収することができる。従って、成長したＳｉＣ単結晶中に発生する残留応力、結晶欠陥、更には、成長したＳｉＣ単結晶の基底面転位の発生をより確実に抑制できる。 As a result, the stress due to the difference in physical properties between the SiC type substrate and the graphite base can be absorbed more reliably. Therefore, it is possible to more reliably suppress the occurrence of residual stress, crystal defects, and basal dislocations of the grown SiC single crystal that occur in the grown SiC single crystal.
　また、上記目的を達成するために、本発明では、上記の結晶成長装置を用いて前記ＳｉＣ種基板上にＳｉＣを結晶成長させることを特徴とする結晶成長方法を提供する。 Further, in order to achieve the above object, the present invention provides a crystal growth method characterized by growing SiC crystals on the SiC type substrate using the above crystal growth apparatus.
　このような結晶成長方法によれば、残留応力や結晶欠陥が抑制され、かつ基底面転位の発生が少ないＳｉＣ単結晶を製造することができる。その結果、成長したＳｉＣ単結晶の結晶品質の向上、及び該ＳｉＣ単結晶中に形成されるデバイスのデバイス特性の向上を図ることができる。 According to such a crystal growth method, it is possible to produce a SiC single crystal in which residual stress and crystal defects are suppressed and basal plane dislocations are less likely to occur. As a result, it is possible to improve the crystal quality of the grown SiC single crystal and the device characteristics of the device formed in the SiC single crystal.
　以上のように、本発明によれば、ＳｉＣ種基板とグラファイト製の土台との物性差による応力を吸収することで、成長したＳｉＣ単結晶の結晶品質の向上を図ることができる結晶成長装置及び結晶成長方法を実現できる。 As described above, according to the present invention, a crystal growth apparatus capable of improving the crystal quality of a grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base. A crystal growth method can be realized.
本発明の結晶成長装置の一例を示す断面図である。It is sectional drawing which shows an example of the crystal growth apparatus of this invention. 本発明の結晶成長方法の一例を示すフローチャートである。It is a flowchart which shows an example of the crystal growth method of this invention. 比較例の結晶成長装置を示す断面図である。It is sectional drawing which shows the crystal growth apparatus of the comparative example. ｔ２／ｔ１と基底面転位密度との関係を示す図である。It is a figure which shows the relationship between t2 / t1 and the dislocation density of the basal plane.
　上記のとおり、昇華法によるＳｉＣ単結晶成長では、ＳｉＣ種基板とその土台となるグラファイト材料との物性差のために、成長したＳｉＣ単結晶中に残留応力や結晶欠陥が生じてしまい、これらが結晶品質を劣化させる要因となっていた。また、該残留応力が原因となって、成長したＳｉＣ単結晶の基底面転位の発生が多くなり、該ＳｉＣ単結晶中に形成されるデバイスのデバイス特性が劣化する問題があった。 As described above, in the SiC single crystal growth by the sublimation method, residual stress and crystal defects occur in the grown SiC single crystal due to the difference in physical properties between the SiC type substrate and the graphite material that is the base thereof. It was a factor that deteriorated the crystal quality. Further, due to the residual stress, the occurrence of dislocations of the basal plane of the grown SiC single crystal increases, and there is a problem that the device characteristics of the device formed in the SiC single crystal deteriorate.
　このようなことから、ＳｉＣ種基板とグラファイト製の土台との物性差による応力を吸収することで、成長したＳｉＣ単結晶の結晶品質の向上を図ることができる結晶成長装置及び結晶成長方法の開発が望まれていた。 Therefore, development of a crystal growth device and a crystal growth method capable of improving the crystal quality of the grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base. Was desired.
　本発明者は、上記問題について鋭意検討を重ねた結果、まず、ＳｉＣ種基板とグラファイト製の土台との物性差による応力を有効に吸収するためには、どのような手法を用いることが有効であるかを検討した。その結果、該応力をＳｉＣ種基板が取り付けられるグラファイト製の土台の変形により吸収することが、成長したＳｉＣ単結晶の基底面転位の発生を抑制するために有効であることを見出した。 As a result of diligent studies on the above problems, the present inventor first, in order to effectively absorb the stress due to the difference in physical properties between the SiC type substrate and the graphite base, what kind of method is effective. I examined whether there was. As a result, it was found that it is effective to absorb the stress by deformation of the graphite base on which the SiC type substrate is attached in order to suppress the occurrence of basal dislocation of the grown SiC single crystal.
　更に、本発明者は、グラファイト製の土台の変形により、該基底面転位の発生を所定の結晶品質内、具体的には、成長したＳｉＣ単結晶の基底面転位密度を３，３２１／ｃｍ２未満とするためには、ＳｉＣ種基板とグラファイト製の土台との関係をどのようにしたらよいかについて鋭意検討した。その結果、ＳｉＣ種基板の厚みをｔ１とし、グラファイト製の土台の厚みをｔ２とした場合に、ｔ２／ｔ１を５未満とすることで、上記所定の結晶品質を維持できることを見出し、本発明を完成させた。 Furthermore, the present inventor has determined that the occurrence of basal plane dislocations is within a predetermined crystal quality due to the deformation of the graphite base, specifically, the basal plane dislocation density of the grown SiC single crystal is 3,321 / cm 2. In order to make it less than that, we diligently examined how the relationship between the SiC type substrate and the graphite base should be. As a result, it was found that when the thickness of the SiC type substrate is t1 and the thickness of the graphite base is t2, t2 / t1 is set to less than 5, and the above-mentioned predetermined crystal quality can be maintained. It was completed.
　すなわち、本発明は、昇華法によりＳｉＣ原料を加熱して昇華させることでＳｉＣ種基板上にＳｉＣを結晶成長させる結晶成長装置であって、前記ＳｉＣ原料を収容する本体と、前記ＳｉＣ種基板を貼り付ける土台を兼ねるとともに前記ＳｉＣ種基板が内側を向いた状態で前記本体の上部に取り付けられる蓋体とからなるグラファイト製の成長容器と、前記成長容器を取り囲む断熱材と、前記ＳｉＣ原料を加熱するヒータとを備え、前記ＳｉＣ種基板の厚みをｔ１とし、前記土台の厚みをｔ２とした場合に、ｔ２／ｔ１が５未満であることを特徴とする結晶成長装置である。 That is, the present invention is a crystal growth apparatus for crystal-growing SiC on a SiC type substrate by heating and sublimating the SiC raw material by a sublimation method, wherein the main body accommodating the SiC raw material and the SiC type substrate are combined. A growth container made of graphite, which also serves as a base for attachment and is a lid attached to the upper part of the main body with the SiC type substrate facing inward, a heat insulating material surrounding the growth container, and the SiC raw material are heated. The crystal growth apparatus is characterized in that t2 / t1 is less than 5 when the thickness of the SiC type substrate is t1 and the thickness of the base is t2.
　以下、本発明の実施の形態について、添付した図面に基づいて具体的に説明するが、本発明は、これらに限定されるものではない。 Hereinafter, embodiments of the present invention will be specifically described with reference to the attached drawings, but the present invention is not limited thereto.
　図１は、本発明の結晶成長装置の一例を示す。
　この結晶成長装置１は、昇華法によりＳｉＣ原料５を加熱して昇華させることでＳｉＣ種基板４上にＳｉＣ（単結晶）を結晶成長させる結晶成長装置である。 FIG. 1 shows an example of the crystal growth apparatus of the present invention.
The crystal growth device 1 is a crystal growth device that grows SiC (single crystal) on a SiC type substrate 4 by heating and sublimating the SiC raw material 5 by a sublimation method.
　結晶成長装置１は、耐熱性を有するグラファイト製の成長容器と、該成長容器を取り囲む断熱材（炉）６と、前記成長容器内のＳｉＣ原料（例えば、ＳｉＣ粉末原料）５を加熱するヒータ７とを備える。成長容器は、ＳｉＣ原料５を収容可能なグラファイト製の本体２と、ＳｉＣ種基板４を貼り付ける土台を兼ねるとともにＳｉＣ種基板４が内側を向いた状態で本体２の上部に取り付けられるグラファイト製の蓋体３とを備える。 The crystal growth apparatus 1 is a heater 7 that heats a heat-resistant graphite growth container, a heat insulating material (fire pot) 6 surrounding the growth container, and a SiC raw material (for example, SiC powder raw material) 5 in the growth container. And. The growth container is made of graphite, which serves as a base for attaching the SiC type substrate 4 and a graphite main body 2 capable of accommodating the SiC raw material 5, and is attached to the upper part of the main body 2 with the SiC type substrate 4 facing inward. A lid 3 is provided.
　本体２は、例えば、底部を有する円筒形を有し、ＳｉＣ原料５は、本体２の底部に配置される。また、本体２の上部は、オープンである。そして、蓋体３は、例えば、円板形を有することで、本体２上部の段差部に取り付け可能となっている。 The main body 2 has, for example, a cylindrical shape having a bottom, and the SiC raw material 5 is arranged at the bottom of the main body 2. Further, the upper part of the main body 2 is open. The lid 3 has a disk shape, for example, so that the lid 3 can be attached to a stepped portion on the upper portion of the main body 2.
　断熱材（炉）６は、チャンバー又は石英管であってよい。断熱材６は、その上部に不活性ガス（例えば、Ａｒガス）を導入するためのガス導入口（不図示）を有する。不活性ガス供給部からの不活性ガスは、ガス導入口から炉内に導入され、該炉内の圧力を調整する。該炉内に導入された不活性ガスは、図示しないガス排出口から排出される。 The heat insulating material (furnace) 6 may be a chamber or a quartz tube. The heat insulating material 6 has a gas introduction port (not shown) on the upper portion thereof for introducing an inert gas (for example, Ar gas). The inert gas from the Inactive gas supply unit is introduced into the furnace through the gas inlet and adjusts the pressure in the furnace. The inert gas introduced into the furnace is discharged from a gas outlet (not shown).
　ヒータ７は、断熱材６の外部に配置される。ヒータ７は、例えば、ＲＨ加熱器（抵抗加熱器）、ＲＦ加熱器（高周波加熱器）などを用いることができ、ＳｉＣ原料５を２０００℃以上の超高温に加熱する機能を有する。 The heater 7 is arranged outside the heat insulating material 6. As the heater 7, for example, an RH heater (resistor heater), an RF heater (high frequency heater), or the like can be used, and the SiC raw material 5 has a function of heating to an ultra-high temperature of 2000 ° C. or higher.
　そして、上記の結晶成長装置１において、ＳｉＣ種基板４の厚みをｔ１とし、その土台としての蓋体３の厚みをｔ２とした場合に、ｔ２／ｔ１は、５未満、さらに好ましくは、３以下に設定されている。これにより、ＳｉＣ種基板４上にＳｉＣを結晶成長させる時に生じるＳｉＣ種基板の熱応力を該土台の熱変形により吸収できるため、成長したＳｉＣの結晶品質の向上、特に、基底面転位の発生の抑制を実現できる。なお、ｔ２／ｔ１は、下限は特に限定されないが、例えば０．１とすることができる。 Then, in the above crystal growth apparatus 1, when the thickness of the SiC type substrate 4 is t1 and the thickness of the lid 3 as the base thereof is t2, t2 / t1 is less than 5, more preferably 3 or less. Is set to. As a result, the thermal stress of the SiC type substrate generated when the SiC is crystal-grown on the SiC type substrate 4 can be absorbed by the thermal deformation of the base, so that the crystal quality of the grown SiC can be improved, particularly the occurrence of basal plane dislocations. Suppression can be achieved. The lower limit of t2 / t1 is not particularly limited, but may be, for example, 0.1.
　また、ＳｉＣ種基板４の土台としての蓋体３の厚みｔ２は、０．８ｍｍ以上であることが好ましい。これにより、蓋体３の強度を確保し、ＳｉＣ種基板４の土台としての機能を十分に発揮できる。 Further, the thickness t2 of the lid 3 as the base of the SiC type substrate 4 is preferably 0.8 mm or more. As a result, the strength of the lid 3 can be ensured, and the function as the base of the SiC type substrate 4 can be fully exhibited.
　なお、本例では、蓋体３は、一定の厚みを有する円板形を有するが、これに限られない。例えば、蓋体３は、中央部が端部よりも薄い円板形であってもよい。すなわち、蓋体３の端部の厚みがＳｉＣ種基板４の厚みの５倍以上である場合に、蓋体３の中央部（ＳｉＣ種基板４の土台部分）を端部よりも薄くして、ｔ２／ｔ１を５未満とすることができる。 In this example, the lid 3 has a disk shape having a certain thickness, but is not limited to this. For example, the lid 3 may have a disk shape in which the central portion is thinner than the end portion. That is, when the thickness of the end portion of the lid 3 is 5 times or more the thickness of the SiC type substrate 4, the central portion (base portion of the SiC type substrate 4) of the lid 3 is made thinner than the end portion. t2 / t1 can be less than 5.
　また、上記の結晶成長装置１において、断熱材６に温度測定用の穴９を設け、かつ断熱材６の外部に設けられたパイロメータなどの温度測定器８を用いて、該穴９を通して非接触で成長容器内の温度を測定可能な構成としてもよい。 Further, in the crystal growth apparatus 1, the heat insulating material 6 is provided with a hole 9 for temperature measurement, and a temperature measuring device 8 such as a pyrometer provided outside the heat insulating material 6 is used to make non-contact through the hole 9. The temperature inside the growth vessel may be measurable.
　次に、上記の結晶成長装置１を用いた本発明の結晶成長方法の一例を説明する。
　図２は、本発明の結晶成長方法の一例を示す。
　なお、以下の説明において、各要素の符号は、図１に付された符号に対応する。 Next, an example of the crystal growth method of the present invention using the above crystal growth device 1 will be described.
FIG. 2 shows an example of the crystal growth method of the present invention.
In the following description, the code of each element corresponds to the code attached to FIG.
　まず、ステップＳ１に示すように、成長容器の本体にＳｉＣ原料（ＳｉＣ固体材料）５としてのＳｉＣ粉末材料を充填する。次に、ステップＳ２に示すように、ＳｉＣ種基板４を成長容器の蓋体（土台部分）３に貼り付ける。ここで、ＳｉＣ種基板４の厚みｔ１と、該ＳｉＣ種基板４の土台の厚みｔ２との比（ｔ２／ｔ１）は、５未満、さらに好ましくは３以下に設定されている。 First, as shown in step S1, the main body of the growth container is filled with the SiC powder material as the SiC raw material (SiC solid material) 5. Next, as shown in step S2, the SiC type substrate 4 is attached to the lid (base portion) 3 of the growth container. Here, the ratio (t2 / t1) of the thickness t1 of the SiC type substrate 4 to the thickness t2 of the base of the SiC type substrate 4 is set to less than 5, more preferably 3 or less.
　次に、ステップＳ３に示すように、ＳｉＣ種基板４が内側を向いた状態で成長容器の本体２の上部に蓋体３を取り付ける。また、ステップＳ４に示すように、該成長容器をチャンバーとしての断熱材６内にセットする。この後、例えば、チャンバー内を真空排気しながら、該チャンバー内にＡｒガスなどの不活性ガスを導入することで、該チャンバー内に所定圧力の不活性ガス雰囲気を作る。 Next, as shown in step S3, the lid 3 is attached to the upper part of the main body 2 of the growth container with the SiC type substrate 4 facing inward. Further, as shown in step S4, the growth container is set in the heat insulating material 6 as a chamber. After that, for example, an inert gas such as Ar gas is introduced into the chamber while vacuum exhausting the inside of the chamber to create an inert gas atmosphere having a predetermined pressure in the chamber.
　次に、ステップＳ５に示すように、ヒータ７によりＳｉＣ原料５を加熱し、かつ成長容器を２０００℃以上の温度にまで昇温し、さらに、温度測定用の穴９を通して温度測定器８により成長容器内の温度を測定し、この測定結果を基にヒータ７の出力を制御することで、温度調節しながらＳｉＣ原料５を昇華させる。 Next, as shown in step S5, the SiC raw material 5 is heated by the heater 7, the growth container is heated to a temperature of 2000 ° C. or higher, and the growth vessel is further grown by the temperature measuring device 8 through the hole 9 for temperature measurement. By measuring the temperature inside the container and controlling the output of the heater 7 based on the measurement result, the SiC raw material 5 is sublimated while adjusting the temperature.
　その結果、ステップＳ６に示すように、ＳｉＣ種基板４上にＳｉＣ結晶（単結晶）が成長する。 As a result, as shown in step S6, a SiC crystal (single crystal) grows on the SiC type substrate 4.
　以上の結晶成長装置及び結晶成長方法によれば、ｔ２（土台の厚み）／ｔ１（ＳｉＣ種基板の厚み）を５未満とすることで、ＳｉＣ種基板とグラファイト製の土台との物性差による応力（熱応力）を該土台の変形により吸収することができる。その結果、成長したＳｉＣ単結晶中に発生する残留応力や結晶欠陥を抑制でき、結晶品質の向上を図ることができる。特に、成長したＳｉＣ単結晶の基底面転位の発生を抑制できることから、該ＳｉＣ単結晶中に形成されるデバイス（パワーデバイスなど）のデバイス特性を大きく向上できる。 According to the above crystal growth apparatus and crystal growth method, by setting t2 (thickness of the base) / t1 (thickness of the SiC type substrate) to less than 5, the stress due to the difference in physical properties between the SiC type substrate and the graphite base (Thermal stress) can be absorbed by the deformation of the base. As a result, residual stress and crystal defects generated in the grown SiC single crystal can be suppressed, and crystal quality can be improved. In particular, since the occurrence of basal dislocations of the grown SiC single crystal can be suppressed, the device characteristics of the device (power device or the like) formed in the SiC single crystal can be greatly improved.
　以下に本発明の実施例を挙げて、本発明を詳細に説明するが、これらは、本発明を限定するものではない。 Hereinafter, the present invention will be described in detail with reference to examples of the present invention, but these are not intended to limit the present invention.
（実施例）
　図１の結晶成長装置及び図２の結晶成長方法を用いてＳｉＣ単結晶の成長を行い、成長したＳｉＣ単結晶の基底面転位がどのくらい発生するかを検証した。また、ＳｉＣ種基板の直径を４インチ（約１０ｃｍ）とした。さらに、ＳｉＣ種基板の厚みを一定とし、ＳｉＣ種基板の土台の厚みとして、ｔ２／ｔ１＝１、２、３、４となる４つの蓋体（サンプル）を用意した（実施例１～４）。 (Example)
The SiC single crystal was grown using the crystal growth apparatus of FIG. 1 and the crystal growth method of FIG. 2, and it was verified how much dislocation of the basal plane of the grown SiC single crystal occurred. The diameter of the SiC type substrate was set to 4 inches (about 10 cm). Further, four lids (samples) having a constant thickness of the SiC type substrate and a base thickness of the SiC type substrate having t2 / t1 = 1, 2, 3, and 4 were prepared (Examples 1 to 4). ..
　また、比較例として、実施例１～４と同じＳｉＣ種基板を用いた場合に、ｔ２／ｔ１＝５となる１つの蓋体（サンプル）を用意した。 Further, as a comparative example, one lid (sample) having t2 / t1 = 5 when the same SiC type substrate as in Examples 1 to 4 was used was prepared.
　図３は、比較例の結晶成長装置を示す。
　同図において、図１の結晶成長装置１と同じ要素には同じ符号を付すことで、その詳細な説明を省略する。なお、図３の結晶成長装置１’が図１の結晶成長装置１と異なる点は、蓋体３の厚みｔ２が厚い、具体的には、ｔ２／ｔ１＝５である点にある。 FIG. 3 shows a crystal growth apparatus of a comparative example.
In the figure, the same elements as those of the crystal growth apparatus 1 of FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. The crystal growth device 1'of FIG. 3 is different from the crystal growth device 1 of FIG. 1 in that the thickness t2 of the lid 3 is thick, specifically, t2 / t1 = 5.
（実施例１）
　図１の結晶成長装置を用いて、１ｍｍの厚みｔ１を有するＳｉＣ種基板を１ｍｍの厚みｔ２を有するグラファイト製の蓋体（土台）に貼り付け、該蓋体を成長容器の本体に組み込んだ後に昇華法によりＳｉＣバルク結晶の成長を行った。また、得られたＳｉＣインゴットを、マルチワイヤソーを用いてスライスし、かつ研磨することで、ＳｉＣウェーハを形成した。そして、該ＳｉＣウェーハに対して、溶融ＫＯＨによるエッチングを施し、該ＳｉＣウェーハ中の基底面転位密度を面内８０箇所でカウントし、その平均値を求めた。 (Example 1)
Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 1 mm t2, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
（実施例２）
　図１の結晶成長装置を用いて、１ｍｍの厚みｔ１を有するＳｉＣ種基板を２ｍｍの厚みｔ２を有するグラファイト製の蓋体（土台）に貼り付け、該蓋体を成長容器の本体に組み込んだ後に昇華法によりＳｉＣバルク結晶の成長を行った。また、得られたＳｉＣインゴットを、マルチワイヤソーを用いてスライスし、かつ研磨することで、ＳｉＣウェーハを形成した。そして、該ＳｉＣウェーハに対して、溶融ＫＯＨによるエッチングを施し、該ＳｉＣウェーハ中の基底面転位密度を面内８０箇所でカウントし、その平均値を求めた。 (Example 2)
Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 2 mm, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
（実施例３）
　図１の結晶成長装置を用いて、１ｍｍの厚みｔ１を有するＳｉＣ種基板を３ｍｍの厚みｔ２を有するグラファイト製の蓋体（土台）に貼り付け、該蓋体を成長容器の本体に組み込んだ後に昇華法によりＳｉＣバルク結晶の成長を行った。また、得られたＳｉＣインゴットを、マルチワイヤソーを用いてスライスし、かつ研磨することで、ＳｉＣウェーハを形成した。そして、該ＳｉＣウェーハに対して、溶融ＫＯＨによるエッチングを施し、該ＳｉＣウェーハ中の基底面転位密度を面内８０箇所でカウントし、その平均値を求めた。 (Example 3)
Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 3 mm t2, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
（実施例４）
　図１の結晶成長装置を用いて、１ｍｍの厚みｔ１を有するＳｉＣ種基板を４ｍｍの厚みｔ２を有するグラファイト製の蓋体（土台）に貼り付け、該蓋体を成長容器の本体に組み込んだ後に昇華法によりＳｉＣバルク結晶の成長を行った。また、得られたＳｉＣインゴットを、マルチワイヤソーを用いてスライスし、かつ研磨することで、ＳｉＣウェーハを形成した。そして、該ＳｉＣウェーハに対して、溶融ＫＯＨによるエッチングを施し、該ＳｉＣウェーハ中の基底面転位密度を面内８０箇所でカウントし、その平均値を求めた。 (Example 4)
Using the crystal growth apparatus of FIG. 1, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 4 mm t2, and the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
（比較例）
　図３の結晶成長装置を用いて、１ｍｍの厚みｔ１を有するＳｉＣ種基板を５ｍｍの厚みｔ２を有するグラファイト製の蓋体（土台）に貼り付け、該蓋体を成長容器の本体に組み込んだ後に昇華法によりＳｉＣバルク結晶の成長を行った。また、得られたＳｉＣインゴットを、マルチワイヤソーを用いてスライスし、かつ研磨することで、ＳｉＣウェーハを形成した。そして、該ＳｉＣウェーハに対して、溶融ＫＯＨによるエッチングを施し、該ＳｉＣウェーハ中の基底面転位密度を面内８０箇所でカウントし、その平均値を求めた。 (Comparison example)
Using the crystal growth apparatus of FIG. 3, a SiC type substrate having a thickness of 1 mm t1 is attached to a graphite lid (base) having a thickness of 5 mm t2, and after the lid is incorporated into the main body of the growth vessel. SiC bulk crystals were grown by the sublimation method. Further, the obtained SiC ingot was sliced and polished using a multi-wire saw to form a SiC wafer. Then, the SiC wafer was etched with molten KOH, and the basal plane dislocation density in the SiC wafer was counted at 80 in-plane points, and the average value was obtained.
（検証結果）
　・実施例１において、基底面転位密度の平均値は、　９６５／ｃｍ２であった。
　・実施例２において、基底面転位密度の平均値は、　９８０／ｃｍ２であった。
　・実施例３において、基底面転位密度の平均値は、１０９６／ｃｍ２であった。
　・実施例４において、基底面転位密度の平均値は、１９７１／ｃｍ２であった。
　・比較例において、基底面転位密度の平均値は、　３３２１／ｃｍ２であった。 (inspection result)
-In Example 1, the average value of the dislocation density of the basal plane was 965 / cm 2 .
-In Example 2, the average value of the dislocation density of the basal plane was 980 / cm 2 .
-In Example 3, the average value of the dislocation density of the basal plane was 1096 / cm 2 .
-In Example 4, the average value of the basal plane dislocation density was 1971 / cm 2 .
-In the comparative example, the average value of the dislocation density of the basal plane was 3321 / cm 2 .
　図４は、ｔ２／ｔ１と基底面転位密度との関係を示す。
　この関係は、実施例１～４及び比較例の結果をまとめたものである。 FIG. 4 shows the relationship between t2 / t1 and the basal dislocation density.
This relationship summarizes the results of Examples 1 to 4 and Comparative Examples.
　同図から明らかなように、ｔ２／ｔ１を横軸とし、基底面転位密度を縦軸とした場合に、ｔ２／ｔ１の増加に応じて、基底面転位密度は、指数関数的に増加することが判明した。特に、ｔ２／ｔ１が５以上となると、基底面転位密度が急激に増加することが分かった。従って、ｔ２／ｔ１を５未満とすることで、ＳｉＣウェーハの基底面転位密度を３，３２１／ｃｍ２未満とし、該ＳｉＣウェーハの結晶品質を向上できることが確認された。 As is clear from the figure, when t2 / t1 is the horizontal axis and the basal dislocation density is the vertical axis, the basal dislocation density increases exponentially as t2 / t1 increases. There was found. In particular, it was found that when t2 / t1 was 5 or more, the dislocation density of the basal plane increased sharply. Therefore, it was confirmed that by setting t2 / t1 to less than 5, the basal dislocation density of the SiC wafer can be set to less than 3,321 / cm 2 , and the crystal quality of the SiC wafer can be improved.
　また、ｔ２／ｔ１を３以下とすることで、ＳｉＣウェーハの基底面転位密度を１，０９６／ｃｍ２以下とすることができるため、該ＳｉＣウェーハの結晶品質をさらに向上できることが確認された。 Further, it was confirmed that the crystal quality of the SiC wafer can be further improved because the basal dislocation density of the SiC wafer can be set to 1,096 / cm 2 or less by setting t2 / t1 to 3 or less.
　この検証結果から分かるように、実施例では、ｔ２／ｔ１を５未満とすることでＳｉＣウェーハの結晶品質を向上できることが立証された。 As can be seen from this verification result, in the examples, it was proved that the crystal quality of the SiC wafer can be improved by setting t2 / t1 to less than 5.
　以上、説明してきたように、本発明によれば、ＳｉＣ種基板とグラファイト製の土台との物性差による応力を吸収することで、成長したＳｉＣ単結晶の結晶品質の向上を図ることができる結晶成長装置及び結晶成長方法を実現できる。 As described above, according to the present invention, a crystal capable of improving the crystal quality of a grown SiC single crystal by absorbing the stress due to the difference in physical properties between the SiC type substrate and the graphite base. A growth apparatus and a crystal growth method can be realized.
　なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。 The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Claims (3)

  1. 　昇華法によりＳｉＣ原料を加熱して昇華させることでＳｉＣ種基板上にＳｉＣを結晶成長させる結晶成長装置であって、
    　前記ＳｉＣ原料を収容する本体と、前記ＳｉＣ種基板を貼り付ける土台を兼ねるとともに前記ＳｉＣ種基板が内側を向いた状態で前記本体の上部に取り付けられる蓋体とからなるグラファイト製の成長容器と、
    　前記成長容器を取り囲む断熱材と、
    　前記ＳｉＣ原料を加熱するヒータとを備え、
    　前記ＳｉＣ種基板の厚みをｔ１とし、前記土台の厚みをｔ２とした場合に、ｔ２／ｔ１が５未満であることを特徴とする結晶成長装置。     A crystal growth device that grows SiC crystals on a SiC type substrate by heating and sublimating a SiC raw material by a sublimation method.
    A graphite growth container including a main body for accommodating the SiC raw material, a base for attaching the SiC type substrate, and a lid attached to the upper part of the main body with the SiC type substrate facing inward.
    The heat insulating material surrounding the growth container and
    A heater for heating the SiC raw material is provided.
    A crystal growth apparatus characterized in that t2 / t1 is less than 5 when the thickness of the SiC type substrate is t1 and the thickness of the base is t2.
  2. 　前記ｔ２／ｔ１が３以下であることを特徴とする請求項１に記載の結晶成長装置。 The crystal growth apparatus according to claim 1, wherein t2 / t1 is 3 or less.
  3. 　請求項１又は２に記載の結晶成長装置を用いて前記ＳｉＣ種基板上にＳｉＣを結晶成長させることを特徴とする結晶成長方法。 A crystal growth method comprising growing SiC crystals on the SiC type substrate using the crystal growth apparatus according to claim 1 or 2.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010030828A (en) * 2008-07-28 2010-02-12 Bridgestone Corp Production method of silicon carbide single crystal and apparatus
US20140225127A1 (en) * 2011-12-28 2014-08-14 Sicrystal Aktiengesellschaft Monocrystalline sic substrate with a non-homogeneous lattice plane course
JP2014159347A (en) * 2013-02-20 2014-09-04 Sumitomo Electric Ind Ltd Manufacturing apparatus and method of silicon carbide single crystal substrate
JP2016531836A (en) * 2013-09-06 2016-10-13 ジーティーエイティー コーポレーションＧｔａｔ Ｃｏｒｐｏｒａｔｉｏｎ Method for producing bulk silicon carbide

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010030828A (en) * 2008-07-28 2010-02-12 Bridgestone Corp Production method of silicon carbide single crystal and apparatus
US20140225127A1 (en) * 2011-12-28 2014-08-14 Sicrystal Aktiengesellschaft Monocrystalline sic substrate with a non-homogeneous lattice plane course
JP2014159347A (en) * 2013-02-20 2014-09-04 Sumitomo Electric Ind Ltd Manufacturing apparatus and method of silicon carbide single crystal substrate
JP2016531836A (en) * 2013-09-06 2016-10-13 ジーティーエイティー コーポレーションＧｔａｔ Ｃｏｒｐｏｒａｔｉｏｎ Method for producing bulk silicon carbide

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