US 12,322,582 B2
Anomalous plasma event detection and mitigation in semiconductor processing
Sunil Kapoor, Vancouver, WA (US); Karl Frederick Leeser, West Linn, OR (US); Noah Baker, West Linn, OR (US); Liang Meng, Sherwood, OR (US); and Yukinori Sakiyama, West Linn, OR (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/310,574
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Feb. 7, 2020, PCT No. PCT/US2020/017193
§ 371(c)(1), (2) Date Aug. 11, 2021,
PCT Pub. No. WO2020/167601, PCT Pub. Date Aug. 20, 2020.
Claims priority of provisional application 62/805,416, filed on Feb. 14, 2019.
Claims priority of provisional application 62/805,261, filed on Feb. 13, 2019.
Prior Publication US 2022/0037135 A1, Feb. 3, 2022
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32944 (2013.01) [H01J 37/32165 (2013.01); H01J 37/32972 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of detecting an anomalous plasma event in a semiconductor processing chamber, the method comprising:
detecting an optical signal emitted by a plasma in the semiconductor processing chamber, wherein the plasma is formed in response to an RF signal from an RF generator;
converting the optical signal to an analog voltage signal;
filtering the analog voltage signal to form a low-pass filtered voltage signal;
comparing the low-pass filtered voltage signal with the analog voltage signal to determine whether changes associated with the low-pass filtered voltage signal exceed a threshold; and
adjusting, based at least in part on the determination, an output parameter of the RF signal from the RF generator.