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 |
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.
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