Patent ID: 11874229
Assignee: ONTO INNOVATION INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical metrology device for Raman spectroscopy, comprising:
a first excitation source that generates a first light beam with a first wavelength;
a second excitation source that generates a second light beam with a second wavelength;
a first dichroic beam splitter that partially reflects the first wavelength and transmits the second wavelength so that the first light beam and the second light beam propagate along a same optical axis that is incident on a sample, the first dichroic beam splitter receives a first Raman response emitted from the sample in response to the first light beam, a second Raman response that is emitted from the sample in response to the second light beam, the first light beam reflected from the sample, and the second light beam reflected from the sample, the first dichroic beam splitter directs the first Raman response and the second Raman response together without the first light beam reflected from the sample towards at least one spectrometer;
the at least one spectrometer that receives from the first dichroic beam splitter the first Raman response and the second Raman response that are emitted from the sample, wherein the at least one spectrometer comprises a first spectrometer that receives the first Raman response that is emitted from the sample in response to the first light beam, and a second spectrometer that receives the second Raman response that is emitted from the sample in response to the second light beam; and
a second dichroic beam splitter that separates the first Raman response and the second Raman response, directs the first Raman response towards the first spectrometer, and directs the second Raman response towards the second spectrometer.