US 11,940,620 B2
Method of cleaning collector of EUV light source system
Changsoon Lim, Hwaseong-si (KR); Youngdo Kim, Hwaseong-si (KR); Daewon Kang, Seoul (KR); Chansoo Kang, Hwaseong-si (KR); Hoonseop Kim, Suwon-si (KR); Sangki Nam, Seongnam-si (KR); Youngduk Suh, Seoul (KR); Donghyub Lee, Hwaseong-si (KR); and Jonghun Pi, Gunwi-gun (KR)
Assigned to Samsung Electronics Co., Ltd., Gyeonggi-do (KR)
Filed by Samsung Electronics Co., Ltd., Suwon-si (KR)
Filed on Oct. 22, 2021, as Appl. No. 17/508,224.
Claims priority of application No. 10-2021-0037580 (KR), filed on Mar. 23, 2021.
Prior Publication US 2022/0308339 A1, Sep. 29, 2022
Int. Cl. G02B 27/00 (2006.01); B08B 7/00 (2006.01); B08B 7/04 (2006.01); G01N 33/00 (2006.01); G03F 7/00 (2006.01); G06T 7/00 (2017.01)
CPC G02B 27/0006 (2013.01) [B08B 7/0035 (2013.01); B08B 7/04 (2013.01); G01N 33/0027 (2013.01); G03F 7/70033 (2013.01); G03F 7/7085 (2013.01); G03F 7/70925 (2013.01); G06T 7/001 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of cleaning a collector of an extreme ultraviolet light source system, comprising:
introducing the collector, separated from the extreme ultraviolet light source system, into a chamber of a cleaning apparatus, the cleaning apparatus including a controller;
capturing an optical image of a reflective surface of the collector;
measuring a contamination level of the reflective surface by comparing the optical image with a prestored standard image;
performing a first cleaning process if the contamination level exceeds a preset first reference value, the first cleaning process including cleaning the reflective surface by spraying dry ice particles onto the reflective surface; and
performing a second cleaning process if the contamination level is less than or equal to the preset first reference value, the second cleaning process including cleaning the reflective surface by radiating atmospheric plasma onto the reflective surface,
wherein the second cleaning process includes,
measuring a microcontamination level of the reflective surface and a damage level of the reflective surface,
generating a microcontamination level map of the reflective surface and a damage level map of the reflective surface, based on the microcontamination level and the damage level, and
cleaning by radiating the atmospheric plasma onto an area of the reflective surface in which the microcontamination level and the damage level exceed a preset second reference value and a present third reference value, respectively, based on the microcontamination level map and the damage level map, and
wherein the controller is configured to control an operation of the cleaning apparatus such that the cleaning apparatus performs the first cleaning process if the contamination level exceeds the preset first reference value and the cleaning apparatus performs the second cleaning process if the contamination level is less than or equal to the preset first reference value.