METHOD OF MANUFACTURING HIGH-PURITY SiC CRYSTAL

Patent metadata

Field	Value
Publication number	US-2023141427-A1
Application number	US-202218054439-A
Country	US
Kind code	A1
Filing date	Nov 10, 2022
Priority date	Nov 11, 2021
Publication date	May 11, 2023
Grant date	—

Abstract

A method of preparing a high-purity silicon carbide (SiC) crystal, and more specifically, to a method of preparing high-purity SiC having an extremely low impurity content in an excellent yield and in large quantities. The method including preparing a reactor containing a reaction chamber; heating the conductive heating element in the reaction chamber; mixing a silicon precursor, a carbon precursor, and a carrier gas; injecting the mixed gas into the reaction chamber, depositing SiC on the conductive heating element and harvesting the deposited SiC crystals.

First claim

1 . A method of preparing a high-purity SiC crystal, comprising:
i) preparing a reactor containing a reaction chamber, wherein the reactor comprises a pair of electrodes connected to a power source and at least one pair of conductive heating elements electrically connected to the electrodes; ii) heating the at least one pair of conductive heating elements; iii) mixing a silicon source precursor, a carbon source precursor, and a carrier gas; iv) injecting the mixed gas into the reaction chamber; v) depositing SiC on the at least one pair of conductive heating elements; and vi) harvesting the deposited SiC crystals by separating the same from the at least one pair of conductive heating elements.

2 . The method of claim 1 , wherein the temperature inside the reaction chamber is 1,000° C. to 1,500° C.

3 . The method of claim 1 , wherein the temperature of the conductive heating element is raised to 1,000° C. to 1,800° C.

4 . The method of claim 1 , wherein the conductive heating element is made from a material selected from molybdenum (Mo), tungsten (W), platinum (Pt), graphite, carbon fiber reinforced carbon (CFRC), SiC and polysilicon.

5 . The method of claim 1 , wherein the at least one pair of the conductive heating elements has one or more pairs of filaments.

6 . The method of claim 1 , wherein a SiC deposition rate on the at least one pair of conductive heating elements is 10 g/hr or more.

7 . The method of claim 1 , wherein the silicon source precursor is one or more selected from trichlorosilane (TCS), dichlorosilane (DCS), silicon tetrachloride (STC) and monosilane.

8 . The method of claim 7 , wherein the silicon source precursor is trichlorosilane (TCS).

9 . The method of claim 1 , wherein the carbon source precursor is propane (C 3 H 8 ).

10 . The method of claim 1 , wherein the carrier gas is hydrogen (H 2 ).

11 . The method of claim 1 , wherein an atomic ratio of Si:C between the silicon source precursor and the carbon source precursor in the mixed gas is 0.5 to 2:1.

12 . The method of claim 11 , wherein an atomic ratio of Si:C between the silicon source precursor and the carbon source precursor in the mixed gas is 1:1.

13 . A SiC crystal manufactured by the method according to claim 1 , wherein the SiC crystal has a purity of 6N or higher.

14 . The SiC crystal of claim 13 , wherein the SiC crystal has a single phase, wherein the phase is the β phase.

15 . The SiC crystal of claim 13 , wherein the SiC crystal has a complex phase in which the α phase and the β phase coexist.

16 . The SiC crystal of claim 13 , wherein a total content of metallic impurities is 1 ppm or less.

Assignees

• Oci Co Ltd

Inventors

• Kim Gabok
• Kang Byungchang
• Park Byunghyun
• Jeon Junki
• Jeong Changwon
• Chyun Seungan

Classifications

• C01P2006/80

  Compositional purity · CPC title

• C30B29/36

  Carbides · CPC title

• C23C16/01

  on temporary substrates, e.g. substrates subsequently removed by etching · CPC title

• C23C16/0209

  by heating · CPC title

• C23C16/46

  characterised by the method used for heating the substrate (C23C16/48, C23C16/50 take precedence) · CPC title