IP Library Granted Patent US 11,371,163
Granted Patent B2
US 11,371,163 · App. 16/751,246 · Granted Jun 28, 2022

Stabilized, high-doped silicon carbide

Inventors: Adrian Powell (Cary, NC); Al Burk (Chapel Hill, NC); Michael O'Loughlin (Chapel Hill, NC)
Assignee: Wolfspeed, Inc.
C30B29/36C30B23/02C30B23/025C30B23/063C30B23/066C30B33/00H01L29/167H01L29/1608H01L29/36
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Quick Facts
Patent No.
US 11,371,163
App. No.
16/751,246
Granted
Jun 28, 2022
Kind
B2
Abstract

Stabilized, high-doped silicon carbide is described. A silicon carbide crystal is grown on a substrate using chemical vapor deposition so that the silicon carbide crystal includes a dopant and the strain compensating component. The strain compensating component can be an isoelectronic element and/or an element with the same majority carrier type as the dopant. The silicon carbide crystal can then be cut into silicon carbide wafers. In some embodiments, the dopant is n-type and the strain compensating component is selected from a group comprising germanium, tin, arsenic, phosphorus, and combinations thereof. In some embodiments, the strain compensating component comprises germanium and the dopant is nitrogen.

Claims (29)

1. A method of producing a silicon carbide wafer, comprising:

placing a seed in a growth zone;

introducing a nitrogen dopant and a strain compensating component in the growth zone;

positioning a source material in the growth zone;

sublimating a silicon carbide crystal on the seed; and

cutting the silicon carbide crystal into a wafer,

wherein the silicon carbide wafer includes the nitrogen dopant at a nitrogen concentration of from 1×10 18 cm −3 to 1×10 21 cm −3 and the strain compensating component at a strain compensating component concentration of from 2×10 18 cm −3 to 2×10 20 cm −3 , and

wherein the strain compensating component comprises an isoelectronic element and/or an element with the same majority carrier type as the nitrogen dopant.

2. The method of claim 1 wherein the strain compensating component is selected from a group comprising germanium, tin, arsenic, phosphorus, and combinations thereof.

3. The method of claim 1 wherein the strain compensating component comprises germanium.

4. The method of claim 1 wherein the nitrogen concentration of the nitrogen dopant in the silicon carbide wafer is from 1×10 18 cm −3 to 1.8×10 20 cm −3 .

5. A silicon carbide wafer having a width dimension of from 100 mm to 300 mm comprising a strain compensating component and a n-type dopant at a concentration of about 1×10 21 cm −3 , a concentration of the strain compensating component in the silicon carbide wafer from 1% to 180% of the concentration of the n-type dopant, the strain compensating component including an isoelectronic element and/or an element with the same majority carrier type as the n-type dopant wherein the strain compensating component is selected from a group comprising germanium, tin, arsenic, phosphorus, all and combinations thereof.

6. The silicon carbide wafer of claim 5 the strain compensating component is in a concentration from 2×10 17 cm −3 to 1×10 21 cm −3 .

7. The silicon carbide wafer of claim 5 wherein the strain compensating component comprises germanium and the concentration of the strain compensating component in the silicon carbide wafer is from 2×10 17 cm −3 to 1.8×10 20 cm −3 .

8. The silicon carbide wafer of claim 5 wherein the n-type dopant comprises nitrogen.

9. The silicon carbide wafer of claim 5 having a resistivity of less than 0.01 ohm-cm.

10. The silicon carbide wafer of claim 8 wherein the concentration of the strain compensating component is between 3% and 120% of the concentration of nitrogen.

11. The silicon carbide wafer of claim 5 wherein the strain compensating component is selected from a group comprising arsenic, phosphorus, and combinations thereof.

12. A method of producing a silicon carbide wafer, comprising:

placing a seed in a growth zone;

introducing a nitrogen dopant and a strain compensating component in the growth zone;

positioning a source material in the growth zone;

sublimating a silicon carbide crystal on the seed; and

cutting the silicon carbide crystal into a wafer,

wherein the silicon carbide wafer includes the nitrogen dopant at a nitrogen concentration of from 1×10 18 cm −3 to 1×10 21 cm −3 and the strain compensating component at a strain compensating component concentration of from 1% to 180% of the nitrogen concentration, and

wherein the strain compensating component comprises an isoelectronic element and/or an element with the same majority carrier type as the nitrogen dopant.

13. The method of claim 12 wherein the strain compensating component is selected from a group comprising germanium, tin, arsenic, phosphorus, and combinations thereof.

14. The method of claim 12 wherein the strain compensating component comprises germanium.

15. The method of claim 12 wherein the nitrogen concentration of the nitrogen dopant in the silicon carbide wafer is from 1×10 18 cm −3 to 1.8×10 20 cm −3 .

Assignments (9)
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Mar 26, 2026
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 075280/0919 →
RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY COLLATERAL AT REEL/FRAME NO. 64185/0755 Recorded Sep 30, 2025
From: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: WOLFSPEED, INC.
Reel/Frame 072989/0001 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0113 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0467 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0588 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0381 →
SECURITY INTEREST Recorded Jun 30, 2023
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 064185/0755 →
CHANGE OF NAME Recorded Jan 24, 2022
From: CREE, INC.
To: WOLFSPEED, INC.
Reel/Frame 058823/0351 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 21, 2022
From: POWELL, ADRIAN; BURK, AL; O'LOUGHLIN, MICHAEL
To: CREE, INC.
Reel/Frame 058718/0017 →