# US 2021/0242017 A1 · Semiconductor wafer

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- Number: US 2021/0242017 A1
- Document ID: US20210242017A1
- Status: Published application
- Kind: A1
- Application number: 16/967,578
- Filed: 2019-02-06
- Published: 2021-08-05
- Earliest claimed: 2018-02-08
- Assignees: Sumitomo Chemical Company, Limited
- Applicants: Sumitomo Chemical Company, Limited
- Inventors: Taiki YAMAMOTO; Keitaro IKEJIRI
- Web page: https://patentgrep.com/patent/US20210242017A1

## CPC

- H10P 14/3216: {Nitrides}
- C30B 25/18: characterised by the substrate
- C30B 25/183: {being provided with a buffer layer, e.g. a lattice matching layer}
- C30B 29/38: Nitrides
- C30B 29/40: AIIIBV compounds {wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi}
- C30B 29/406: {Gallium nitride}
- H10P 14/2905: {Silicon, silicon germanium or germanium}
- H10P 14/3238: {being insulating materials}
- H10P 14/3248: {consisting of two layers}
- H10P 14/3251: {consisting of three or more layers}
- H10P 14/3416: {Nitrides}
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- 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

## Abstract

One embodiment of the present invention provides a semiconductor wafer 1 which is provided with: a substrate 10 that is mainly composed of Si, a buffer layer 11 that is formed on the substrate 10 and comprises an AlN layer 11a as the lowermost layer; and a nitride semiconductor layer 12 that is formed on the buffer layer 11 and contains Ga. This semiconductor wafer 1 is configured such that the pit density of the upper surface of the AlN layer 11a is more than 0 but less than 2.4×1010 cm−2.

## Claims

### Claim 1

A semiconductor wafer, comprising:
a substrate mainly composed of Si;
a buffer layer formed over the substrate and comprises an AlN layer as a lowermost layer; and
a nitride semiconductor layer formed over the buffer layer and includes Ga,
wherein the semiconductor wafer is configured in such a manner that a pit density of an upper surface of the AlN layer is more than 0 but less than 2.4×1010 cm−2.

### Claim 2 (depends on 1)

The semiconductor wafer according to claim 1, wherein the pit density of the upper surface of the AlN layer is not more than 5.5×109 cm−2.

### Claim 3 (depends on 2)

The semiconductor wafer according to claim 2, wherein the pit density of the upper surface of the MN layer is not more than 1.4×109 cm−2.