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. 16, 2013
Filed:
May. 28, 2008
Kaushik Chanda, Fishkill, NY (US);
Ronald G. Filippi, Wappingers Falls, NY (US);
Charles C. Goldsmith, Poughkeepsie, NY (US);
Ping-chuan Wang, Hopewell Junction, NY (US);
Chih-chao Yang, Glenmont, NY (US);
Kaushik Chanda, Fishkill, NY (US);
Ronald G. Filippi, Wappingers Falls, NY (US);
Charles C. Goldsmith, Poughkeepsie, NY (US);
Ping-Chuan Wang, Hopewell Junction, NY (US);
Chih-Chao Yang, Glenmont, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Recrystallization and grain growth of metal, such as Cu, is achieved at higher anneal temperatures of 150° C. to 400° C., for example, for short anneal times of five to sixty minutes by forming a metal stress locking layer on the Cu before anneal and chemical-mechanical polishing. The stress locking layer extends the elastic region of the Cu by suppressing atom diffusion to the free surface, resulting in near zero tensile stress at room temperature after anneal. Stress voiding, which creates reliability problems, is thereby avoided. Improved grain size and texture are also achieved. The stress locking layer is removed after anneal by chemical-mechanical polishing leaving the Cu interconnect with low stress and improved grain size and texture.