US 11,655,146 B2
Extended acid etch for oxide removal
Hong-Ta Kuo, Hsinchu County (TW); I-Shi Wang, Sanxia Township (TW); Tzu-Ping Yang, Hsinchu (TW); Hsing-Yu Wang, Hsinchu (TW); Shu-Han Chao, Hsinchu (TW); Hsi-Cheng Hsu, Taichung (TW); Yin-Tun Chou, Hsinchu (TW); Yuan-Hsin Chi, Longjing Township (TW); and Sheng-Yuan Lin, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Nov. 13, 2020, as Appl. No. 16/949,767.
Prior Publication US 2022/0153574 A1, May 19, 2022
Int. Cl. B81C 3/00 (2006.01); B81C 1/00 (2006.01)
CPC B81C 3/001 (2013.01) [B81C 1/0092 (2013.01); B81C 2201/0133 (2013.01); B81C 2203/036 (2013.01); B81C 2203/0792 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
removing a photoresist layer from a first wafer;
etching, using an acidic etchant, the first wafer for a time duration to remove an oxide from one or more portions of the first wafer,
wherein etching the first wafer for the time duration enables the oxide to be removed from the one or more portions of the first wafer without an intervening preclean process between removing the photoresist layer from the first wafer and etching the first wafer using the acidic etchant;
bonding the first wafer with a second wafer after etching the first wafer; and
bonding the first wafer with a third wafer on an opposite side of the first wafer to which the second wafer is bonded,
wherein the first wafer, the second wafer, and the third wafer form a cavity.