The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jan. 30, 2007

Filed:

Sep. 21, 2004
Applicants:

Yen-chang Chao, Taichung, TW;

You-hua Chou, Taipei, TW;

Yong-ping Chan, Taipei County, TW;

Inventors:

Yen-Chang Chao, Taichung, TW;

You-Hua Chou, Taipei, TW;

Yong-Ping Chan, Taipei County, TW;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 31/26 (2006.01);
U.S. Cl.
CPC ...
Abstract

A method of testing a test wafer includes shielding test centers on a test wafer using shielding tabs during the deposition of a layer. The test wafer has the same size and shape of product wafers. The shielding tabs are then removed from the test wafer. A plurality of predetermined points which are separated from each test center by a critical interval are checked, and whether each point is covered by the layer is determined through an interferometer or a microprobe. The test wafer is processed after adjustments to or maintenance on equipment, or after a fixed number of product wafers have been processed.


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