US 12,334,314 B2
Dry etcher uniformity control by tuning edge zone plasma sheath
Po-Lung Hung, Hsinchu (TW); Yi-Tsang Hsieh, Hsinchu (TW); Yu-Hsi Tang, Hsinchu (TW); Chih-Ching Cheng, Hsinchu (TW); and Chih-Teng Liao, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Aug. 30, 2021, as Appl. No. 17/461,641.
Prior Publication US 2023/0067400 A1, Mar. 2, 2023
Int. Cl. H01L 21/3065 (2006.01); H01J 37/32 (2006.01)
CPC H01J 37/32697 (2013.01) [H01J 37/32568 (2013.01); H01J 37/32642 (2013.01); H01L 21/3065 (2013.01); H01J 37/32082 (2013.01); H01J 2237/3343 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
supporting, in a plasma etching chamber, a wafer surrounded by a focus ring;
generating, in the plasma etching chamber, a plasma above the wafer by applying a first radio frequency voltage between a first electrode below the wafer and a second electrode above the wafer;
generating, with a sensor, sensor signals indicative of a thickness of the focus ring;
receiving the sensor signals with a control system;
adjusting a plasma sheath of the plasma at an edge of the wafer by controlling, with the control system, generation of a supplementary electric field adjacent to the focus ring based on the sensor signals by applying a second radio frequency voltage between the second electrode and a third electrode below the focus ring, the second radio frequency voltage being in-phase with the first radio frequency voltage and having a different amplitude than the first radio frequency voltage; and
etching the wafer with the plasma.