IP Library Granted Patent US 7,785,414
Granted Patent B2
US 7,785,414 · App. 11/597,568 · Granted Aug 31, 2010

Process for manufacturing wafer of silicon carbide single crystal

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,785,414
App. No.
11/597,568
Granted
Aug 31, 2010
Kind
B2
Abstract

A process for manufacturing a wafer of a silicon carbide single crystal having: cutting a wafer from an α (hexagonal)-silicon carbide single crystal so that the off-angle is totally in the range from 0.4 to 2° to a plane obtained in perpendicular to the [0001]c axis of the silicon carbide single crystal; disposing the wafer in a reaction vessel; feeding a silicon source gas and carbon source gas in the reaction vessel; and epitaxially growing the α (hexagonal) silicon carbide single crystal on the wafer by allowing the silicon source gas and carbon source gas to react.

Claims (11)

1. A process for manufacturing a wafer of a silicon carbide single crystal comprising:

cutting a wafer from an α (hexagonal)-silicon carbide single crystal so that the off-angle is totally in the range from 0.4 to 2° to a plane obtained in perpendicular to the [0001]c axis of the silicon carbide single crystal;

disposing the wafer in a reaction vessel;

feeding a silicon source gas and carbon source gas in the reaction vessel; and

epitaxially growing the α (hexagonal) silicon carbide single crystal on the wafer by allowing the silicon source gas and carbon source gas to react at a temperature range from 1550 to 1700° C.,

wherein the feed ratio (C/Si) of the carbon source gas (C) to the silicon source gas (Si) is in the range from 0.5 to 1.4,

wherein the off-angle is increased from 0° in an approximately concentric manner from the center to the periphery of the wafer in order to restrict the area of the wafer with an off-angle of less than 0.4° to the region in the vicinity of the center of the wafer.

2. The process for manufacturing the wafer of the silicon carbide single crystal according to claim 1 , wherein the off-angle is in the range from 0.4 to 1°.

3. The process for manufacturing the wafer of a silicon carbide single crystal according to claim 1 for obtaining a flat surface with a surface roughness (Ry) of 2 nm or less over the entire surface of the wafer.

4. The process for manufacturing the wafer of a silicon carbide single crystal according to claim 3 , wherein the surface roughness (Ry) is 1.5 nm or less.

5. The process for manufacturing the wafer of a silicon carbide single crystal according to claim 1 , wherein the off-angle is in the range from 0.4 to 0.6°.

Assignments (4)
CHANGE OF ADDRESS Recorded Feb 14, 2024
From: RESONAC CORPORATION
To: RESONAC CORPORATION
Reel/Frame 066599/0037 →
CHANGE OF NAME Recorded Jun 23, 2023
From: SHOWA DENKO K.K.
To: RESONAC CORPORATION
Reel/Frame 064082/0513 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 29, 2013
From: BRIDGESTONE CORPORATION
To: SHOWA DENKO K.K.
Reel/Frame 031111/0598 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 27, 2006
From: MARUYAMA, TAKAYUKI; CHIBA, TOSHIMI
To: BRIDGESTONE CORPORATIN
Reel/Frame 018640/0336 →