US 11,721,555 B2
Method and system for thinning wafer thereof
Chien-Ling Hwang, Hsinchu (TW); Bor-Ping Jang, Chu-Bei (TW); Hsin-Hung Liao, Taipei (TW); and Chung-Shi Liu, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsin-Chu (TW)
Filed on Jul. 27, 2020, as Appl. No. 16/939,470.
Application 16/939,470 is a division of application No. 14/842,337, filed on Sep. 1, 2015, granted, now 10,727,074.
Application 14/842,337 is a division of application No. 13/944,257, filed on Jul. 17, 2013, granted, now 9,129,899, issued on Sep. 8, 2015.
Prior Publication US 2020/0357651 A1, Nov. 12, 2020
Int. Cl. H01L 21/308 (2006.01); H01L 21/306 (2006.01); H01L 21/68 (2006.01); H01L 21/67 (2006.01); H01L 21/78 (2006.01); H01L 21/683 (2006.01); C23C 16/458 (2006.01); B05C 21/00 (2006.01)
CPC H01L 21/3083 (2013.01) [H01L 21/3081 (2013.01); H01L 21/30604 (2013.01); H01L 21/6708 (2013.01); H01L 21/682 (2013.01); H01L 21/6835 (2013.01); H01L 21/78 (2013.01); B05C 21/005 (2013.01); C23C 16/4585 (2013.01); H01L 21/6836 (2013.01); H01L 2221/6834 (2013.01); H01L 2221/68327 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for thinning a wafer, comprising:
placing a wafer on a support assembly, wherein the support assembly comprises a plurality of pins;
securing an etching mask to a backside of the wafer, wherein the etching mask has an extending portion which covers a peripheral portion of the wafer, the etching mask has a plurality of circular bores extended along a vertical direction, and the etching mask is secured to the support assembly by connecting the circular bores and the pins, and the etching mask has a plurality of openings, and each of the openings extends from a bottom of an outer side surface of the etching mask; and
performing a wet etching process on the backside of the wafer to form a thinned wafer, wherein the thinned wafer has a peripheral portion with a first thickness and a central portion having a second thickness smaller than the first thickness.