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.
Patent No.:
Date of Patent:
Apr. 23, 2002
Filed:
Nov. 22, 1999
Kuo-Hsien Cheng, Hsin-Chu, TW;
Chen-Peng Fan, Hsin-Chu, TW;
Chien-Chih Chou, Chu-Pei, TW;
Sheng-Yuan Lin, Nan-Tou, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-Chu, TW;
Abstract
A method is provided to prevent the forming of a high de-focusing ledge or step on the back side of a substrate or a semiconductor wafer in order to improve the photolithographic process steps in semiconductor manufacturing. In semiconductor manufacturing, various processes are performed to form various dielectric and metal layers on the front side of wafers. However, some of these materials deposit on the back side of the wafer as well. These unwanted deposits result in contaminants that break off from the back side, causing reliability problems. Those that do stay on, on the other hand, cause irregular topology, thus affecting the focusing of stepper equipment during photolithographic processes. It is disclosed in the present invention a method of forming an oxide layer which prevents the forming of such de-focusing steps on the back side of a wafer.