IP Library Granted Patent US 11,249,027
Granted Patent B2
US 11,249,027 · App. 16/883,866 · Granted Feb 15, 2022

SiC substrate evaluation method and method for manufacturing SiC epitaxtal wafer

Inventors: Yoshitaka Nishihara (Chichibu, JP); Koji Kamei (Hikone, JP)
Assignee: SHOWA DENKO K.K.
G01N21/8806G01N2021/8845H01L29/1608
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 11,249,027
App. No.
16/883,866
Granted
Feb 15, 2022
Kind
B2
Abstract

A SiC epitaxial wafer, including: a SiC substrate; and an epitaxial layer stacked on a first surface of the SiC substrate, wherein an area occupied by bar-shaped stacking faults on the first surface of the SiC substrate is identified, and the area occupied by bar-shaped stacking faults on the first surface of the SiC substrate is equal to or less than ¼ of the first surface area of the SiC substrate.

Claims (9)

1. A SiC epitaxial wafer, comprising:

a SiC substrate;

and an epitaxial layer stacked on a first surface of the SiC substrate,

wherein an area occupied by bar-shaped stacking faults on the first surface of the SiC substrate is identified by irradiating the first surface of the SiC substrate before stacking the epitaxial film with excitation light, and extracting light having a wavelength range from equal to or greater than 405 nm to equal to or less than 445 nm among photoluminescence light beams emitted from the first surface of the SiC substrate, and the area occupied by bar-shaped stacking faults on the first surface of the SiC substrate is equal to or less than ¼ of the first surface area of the SiC substrate, and

wherein an impurity concentration of the SiC substrate is higher than that of the epitaxial layer.

2. The SiC epitaxial wafer according to claim 1 , locations of the bar-shaped stacking faults on the first surface of the SiC substrate are identified.

3. The SiC epitaxial wafer according to claim 1 , a density of the bar-shaped stacking faults on the first surface of the SiC substrate is equal to or less than 10 pieces/cm 2 , wherein the density of the bar-shaped stacking faults on the first surface of the SiC substrate is determined by counting a piece number of the bar-shaped stacking faults per one centimeter square of the first surface of the SiC substrate.

4. The SiC epitaxial wafer according to claim 1 , wherein the impurity concentration of the SiC substrate is from two to three orders of magnitude higher than the impurity concentration of the epitaxial layer.

5. The SiC epitaxial wafer according to claim 1 , wherein the impurity concentration of the SiC substrate is higher than 1×10 18 atom/cm 3 .

Assignments (3)
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 May 26, 2020
From: NISHIHARA, YOSHITAKA; KAMEI, KOJI
To: SHOWA DENKO K.K.
Reel/Frame 052754/0104 →
Priority Claims (1)
JP JP2018-194020 · Oct 15, 2018 · national
Continuity (2)
Continuation 16598486 · Oct 10, 2019
Related Publication 20200284732A1 · Sep 10, 2020