Patent ID: 11940620
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 13:
14. The method of claim 7, wherein
the extreme ultraviolet light source system comprises a light source chamber, a droplet supply unit, and a laser light source,
the collector is in the light source chamber,
the droplet supply unit is on a sidewall of the chamber,
the droplet supply unit is aligned to discharge a droplet along a path traversing an upper portion of the collector,
the second cleaning operation is performed in response to the contamination level being less than or equal to the preset first reference value,
the laser light source is configured to irradiate a laser beam to the droplet, on the path, and
the second cleaning operation is performed by measuring the microcontamination level by detecting a spectrum of a material constituting the droplet in a spectral image of the reflective surface.