US 12,466,727 B2
Extended acid etch for oxide removal
Hong-Ta Kuo, Hsinchu County (TW); I-Shi Wang, Tainan (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 May 1, 2023, as Appl. No. 18/310,000.
Application 18/310,000 is a continuation of application No. 16/949,767, filed on Nov. 13, 2020, granted, now 11,655,146.
Prior Publication US 2023/0264949 A1, Aug. 24, 2023
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:
forming a photoresist layer on a surface of a first wafer;
removing one or more first portions of the photoresist layer from the first wafer to form a pattern in the photoresist layer;
forming one or more actuators in the first wafer by etching the first wafer based on the pattern in the photoresist layer;
removing one or more second portions of the photoresist layer that is remaining after forming the one or more actuators;
removing an oxide from one or more portions of the first wafer by etching, using an acidic etchant, the first wafer for a time duration without performing an intervening preclean process after removing the one or more second portions of the photoresist layer; and
forming, after removing the oxide, a cavity by bonding a second wafer with a first side of the first wafer and bonding a third wafer with a second side of the first wafer.