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:
Nov. 22, 2005
Filed:
Nov. 28, 2003
Chung-yang Tseng, Taipei, TW;
Shih-chin Gong, Taipei, TW;
Reuy-shing Huang, Chiai Hsien, TW;
Tong-an Lee, Pantao, TW;
Kuo-chung Chan, Hsinchu, TW;
Hung-dar Wang, Kaosiung, TW;
Chung-Yang Tseng, Taipei, TW;
Shih-Chin Gong, Taipei, TW;
Reuy-shing Huang, Chiai Hsien, TW;
Tong-An Lee, Pantao, TW;
Kuo-Chung Chan, Hsinchu, TW;
Hung-Dar Wang, Kaosiung, TW;
Asia Pacific Microsystems, Inc., Hsinchu, TW;
Abstract
A method of maintaining photolithographic precision alignment for a wafer after being bonded, wherein two cavities are formed at the rear surface of a top wafer at the position corresponding to alignment marks made on a bottom wafer. The depth of both cavities is deeper than that of a final membrane structure. The top wafer is then bonded to the bottom wafer which already has alignment marks and a microstructure. This bonded wafer is annealed to intensify its bonding strength. After that, a thinning process is applied until the thickness of the top wafer is reduced to thinner than the cavity depth such that the alignment marks are emerged in the top wafer cavities thereby serving as alignment marks for any exposure equipment.