US 12,142,468 B2
Stress treatments for cover wafers
Vinayak Vishwanath Hassan, San Francisco, CA (US); Bhaskar Kumar, Santa Clara, CA (US); Meng Cai, Lynnfield, MA (US); Sowjanya Musunuru, Milpitas, CA (US); Kaushik Alayavalli, Sunnyvale, CA (US); and Andrew Nguyen, San Jose, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Aug. 30, 2021, as Appl. No. 17/460,900.
Prior Publication US 2023/0069395 A1, Mar. 2, 2023
Int. Cl. H01J 37/32 (2006.01); B24B 7/22 (2006.01); C23C 16/44 (2006.01)
CPC H01J 37/32862 (2013.01) [B24B 7/228 (2013.01); C23C 16/4404 (2013.01); H01J 37/32724 (2013.01); H01J 2237/334 (2013.01); H01J 2237/335 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of manufacturing cover wafers, the method comprising:
sintering aluminum nitride particles into a substrate characterized by a thickness and characterized by a disc shape to form a cover wafer;
grinding a surface of the cover wafer to reduce the thickness to less than or about 2 mm;
polishing the surface of the cover wafer to reduce a roughness; and
annealing the cover wafer at a temperature of greater than or about 800° C. for a time period of greater than or about 60 minutes.