# US 5,707,446 A · Device for producing SiC single crystals

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- Number: US 5,707,446 A
- Document ID: US5707446A
- Status: Granted
- Kind: A
- Application number: 08/530,291
- Filed: 1995-09-29
- Granted: 1998-01-13
- Earliest claimed: 1993-04-01
- Assignees: Siemens Aktiengesellschaft
- Inventors: Johannes Volkl; Peter Lanig
- Web page: https://patentgrep.com/patent/US5707446A

## CPC

- C30B 23/06: Heating of the deposition chamber, the substrate or the materials to be evaporated
- C30B 23/00: Single-crystal growth by condensing evaporated or sublimed materials
- C30B 23/002: {Controlling or regulating}
- C30B 29/36: Carbides
- Y10T 117/10: Apparatus
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

SiC single crystals are produced in a reaction chamber, in which there is a seed crystal for the separation of a SiC single crystal from the gas phase. The reaction chamber is connected to a storage chamber, which is at least partly filled with a supply of SiC, by a gas channel with a predetermined cross-section for conveying the SiC in the gas phase. The supply of SiC is sublimated in a heating device and a temperature gradient is adjusted in the reaction chamber. It is, thus, possible to produce SiC single crystals with any desired cross-sectional area and of high crystalline quality and single-crystal yield, because the conveyance rate of the gas molecules can be precisely adjusted.

## Claims

### Claim 1

A device for producing single crystals from a solid SiC supply, including a seed crystal having a crystallization surface, wherein the device comprises:
a) a reaction chamber, wherein the seed crystal is arranged for growing the single SiC crystal out of a gas phase;
b) a supply chamber, which is at least partially filled with the supply of solid SiC;
c) a homogenization chamber;
d) a first gas channel connecting the homogenization chamber to the supply chamber;
e) a second gas channel connecting the homogenization chamber to the reaction chamber; and
f) at least one heating device for producing SiC in the gas phase from the SiC supply in the supply chamber, for controlling the temperature in the homogenization chamber, and for adjusting a temperature distribution in the reaction chamber.

### Claim 2 (depends on 1)

The device according to claim 1, wherein the second gas channel has an exhaust port disposed directly opposite the seed crystal, so that a center axis of the second gas channel is directed at least nearly perpendicularly to the crystallization surface of the seed crystal.

### Claim 3 (depends on 2)

The device according to claim 2, wherein the supply chamber is arranged above the reaction chamber.

### Claim 4 (depends on 2)

The device according to claim 2, wherein the supply chamber is arranged below the reaction chamber.

### Claim 5 (depends on 1)

The device according to claim 1, wherein the supply chamber is arranged above the reaction chamber.

### Claim 6 (depends on 1)

The device according to claim 1, wherein the supply chamber is arranged below the reaction chamber.

### Claim 7 (depends on 1)

The device according to claim 1, wherein a separate heating device is assigned to the homogenization chamber.

### Claim 8 (depends on 1)

The device according to claim 1, wherein the supply chamber, the homogenization chamber, the reaction chamber, and the first and second gas channels are disposed axially to one another.

### Claim 9 (depends on 1)

The device according to claim 1, further comprising means for supplying a protective gas.

### Claim 10

A device for producing single crystals from a solid SiC supply, including a plurality of seed crystals, each seed crystal having a crystallization surface, wherein the device comprises:
a) at least one reaction chamber, wherein the seed crystals are arranged for growing single SiC crystals out of a gas phase;
b) at least one supply chamber, wherein each of said at least one supply chamber is at least partially filled with the supply of solid SiC;
c) at least one homogenization chamber;
d) at least one first gas channel connecting the at least one homogenization chamber to the at least one supply chamber;
e) a plurality of second gas channels connecting the homogenization chamber to the reaction chamber, wherein each second gas channel is directed to a corresponding seed crystal; and
f) at least one heating device for producing SiC in the gas phase from the SiC supply in the at least one supply chamber, for controlling the temperature in the at least one homogenization chamber, and for adjusting a temperature distribution in the at least one reaction chamber.

### Claim 11 (depends on 10)

The device according to claim 10, wherein the seed crystals are arranged in a common reaction chamber.

### Claim 12 (depends on 11)

The device according to claim 11, wherein each of the at least one first gas channels are connected to a common supply chamber.

### Claim 13 (depends on 10)

The device according to claim 10, wherein each of the at least one first gas channels are connected to a common supply chamber.

### Claim 14 (depends on 10)

The device according to claim 10, wherein the at least one reaction chamber is separated from the at least one supply chamber by a thermal insulation wall, and a first heating device is assigned to the at least one reaction chamber, and a second heating device independent of the first heating device is assigned to the at least one supply chamber.