Process of internal gettering for Czochralski silicon wafer
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jun 18, 2013
Grant Date -
Feb 21, 2013
app pub date -
Mar 16, 2012
filing date -
Mar 23, 2011
priority date (Note) -
In Force
status (Latency Note)
![]() |
A preliminary load of PAIR data current through [] has been loaded. Any more recent PAIR data will be loaded within twenty-four hours. |
PAIR data current through []
A preliminary load of cached data will be loaded soon.
Any more recent PAIR data will be loaded within twenty-four hours.
![]() |
Next PAIR Update Scheduled on [ ] |

Importance

US Family Size
|
Non-US Coverage
|
Patent Longevity
|
Forward Citations
|
Abstract
An internal gettering process for a Czochralski silicon wafers comprises: (1) heating a Cz silicon wafer to 1200-1250° C. at a heating rate of 50-100° C./s under a nitrogen atmosphere, maintaining for 30-150 seconds, cooling the Cz silicon wafer to 800-1000° C. first at a cooling rate of 5-50° C./s, and then cooling the Cz silicon wafer naturally; (2) annealing the Cz silicon wafer obtained in the step (1) at 800-900° C. under an argon atmosphere for a period of 8-16 hours. The present invention only involves two heat treatment steps which require lower temperature and shorter time comparing to the conventional processes. The density of the bulk microdefects and the width of the denuded zone can be easily controlled by the temperature, duration and cooling rate of rapid thermal processing in the first step.
First Claim
all claims..Other Claims data not available
Family

- 15 United States
- 10 France
- 8 Japan
- 7 China
- 5 Korea
- 2 Other
Patent Owner(s)
Patent Owner | Address | |
---|---|---|
ZHEJIANG UNIVERSITY | 310013 YUHANG TANG ROAD XIHU DISTRICT HANGZHOU ZHEJIANG 866 HANGZHOU CITY ZHEJIANG PROVINCE 310013 |
International Classification(s)

- 2012 Application Filing Year
- H01L Class
- 20465 Applications Filed
- 18077 Patents Issued To-Date
- 88.34 % Issued To-Date
Inventor(s)
Inventor Name | Address | # of filed Patents | Total Citations |
---|---|---|---|
Ma, Xiangyang | Hangzhou, CN | 5 | 3 |
# of filed Patents : 5 Total Citations : 3 | |||
Wang, Biao | Hangzhou, CN | 225 | 1041 |
# of filed Patents : 225 Total Citations : 1041 | |||
Xu, Ze | Hangzhou, CN | 7 | 10 |
# of filed Patents : 7 Total Citations : 10 | |||
Yang, Deren | Hangzhou, CN | 5 | 2 |
# of filed Patents : 5 Total Citations : 2 |
Cited Art Landscape
- No Cited Art to Display

Patent Citation Ranking
Forward Cite Landscape
- No Forward Cites to Display

Maintenance Fees
Fee | Large entity fee | small entity fee | micro entity fee | due date |
---|---|---|---|---|
11.5 Year Payment | $7400.00 | $3700.00 | $1850.00 | Dec 18, 2024 |
Fee | Large entity fee | small entity fee | micro entity fee |
---|---|---|---|
Surcharge - 11.5 year - Late payment within 6 months | $160.00 | $80.00 | $40.00 |
Surcharge after expiration - Late payment is unavoidable | $700.00 | $350.00 | $175.00 |
Surcharge after expiration - Late payment is unintentional | $1,640.00 | $820.00 | $410.00 |
Full Text

Legal Events
Date | Code | Event | Description |
---|---|---|---|
Apr 25, 2016 | STCH | INFORMATION ON STATUS: PATENT DISCONTINUATION | free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
Mar 25, 2016 | FP | LAPSED DUE TO FAILURE TO PAY MAINTENANCE FEE | Effective Date: Mar 25, 2016 |
Mar 25, 2016 | LAPS | LAPSE FOR FAILURE TO PAY MAINTENANCE FEES | |
Nov 06, 2015 | REMI | MAINTENANCE FEE REMINDER MAILED | |
Sep 23, 2011 | FPAY | FEE PAYMENT | year of fee payment: 4 |
Mar 25, 2008 | I | Issuance | |
Mar 02, 2006 | P | Published | |
Aug 30, 2004 | F | Filing | |
Aug 30, 2004 | PD | Priority Date | |
Aug 27, 2004 | AS | ASSIGNMENT | free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DIRKS, KEITH W.;FREAS, JON;BUCK, ROBERT N., JR.;REEL/FRAME:015757/0696 Owner name: WAHL CLIPPER CORPORATION, ILLINOIS Effective Date: Aug 27, 2004 |

Matter Detail

Renewals Detail
