US 11,655,138 B2
Roughness selectivity for MEMS movement stiction reduction
Hsi-Cheng Hsu, Taichung (TW); Kuo-Hao Lee, Hsinchu (TW); Jui-Chun Weng, Taipei (TW); Ching-Hsiang Hu, Taipei (TW); Ji-Hong Chiang, Changhua (TW); Lavanya Sanagavarapu, Hsinchu (TW); Chia-Yu Lin, Taoyuan (TW); Chia-Chun Hung, Chiayi (TW); Jia-Syuan Li, Taoyuan (TW); and Yu-Pei Chiang, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on May 4, 2021, as Appl. No. 17/302,484.
Claims priority of provisional application 63/198,691, filed on Nov. 4, 2020.
Prior Publication US 2022/0135397 A1, May 5, 2022
Int. Cl. B81B 3/00 (2006.01); B81C 1/00 (2006.01)
CPC B81B 3/0005 (2013.01) [B81C 1/00968 (2013.01); B81C 2201/112 (2013.01); B81C 2201/115 (2013.01)] 20 Claims
OG exemplary drawing
 
8. A micro-electromechanical-system (MEMS) device, comprising:
a capping wafer;
a circuitry wafer comprising a metal bonding pad;
a device wafer, between the capping wafer and the circuitry wafer, comprising:
a support structure, and
a germanium bonding pad between the metal bonding pad and the support structure;
one or more moveable MEMS structures in a cavity formed by the capping wafer, the circuitry wafer, and the device wafer;
a first polysilicon layer on a bottom surface of the one or more moveable MEMS structures; and
a second polysilicon layer between the support structure and the germanium bonding pad,
wherein a surface roughness of the first polysilicon layer is different from a surface roughness of the second polysilicon layer.