Patent ID: 11971663
Assignee: ASML NETHERLANDS B.V.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 6:
7. A light source configured to emit a time-varying spectrum of light in a metrology or lithography system, the light source comprising:
a spectrometer configured to measure a characteristic of the time-varying spectrum of light emitted from the light source, wherein the time-varying spectrum of light is emitted from the light source over a predetermined time window and is conditioned prior to interacting with a target; and
a controller configured to:
determine at least one characteristic of the time-varying spectrum of light emitted from the light source over the predetermined time window, and
use the determined at least one characteristic to control a spectral output of the light source during when the time-varying spectrum of light is conditioned,
wherein when the time-varying spectrum of light is conditioned it is also band-filtered and adjusted, the band-filtering being based on the use of the determined at least one characteristic, and
wherein the adjusting of the band-filtering is done dynamically to reduce variation in a center frequency of the time-varying spectrum of light.