US 12,072,606 B2
Protective coating for nonlinear optical crystal
John Fielden, Los Altos, CA (US); and Yung-Ho Alex Chuang, Cupertino, CA (US)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Jul. 11, 2022, as Appl. No. 17/862,133.
Claims priority of provisional application 63/227,342, filed on Jul. 30, 2021.
Prior Publication US 2023/0034635 A1, Feb. 2, 2023
Int. Cl. G02F 1/355 (2006.01); G01N 21/95 (2006.01); G03F 7/00 (2006.01)
CPC G02F 1/3551 (2013.01) [G01N 21/9501 (2013.01); G03F 7/7015 (2013.01); G03F 7/70591 (2013.01); G01N 2201/068 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A system including:
a light source configured to generate incident light having a wavelength in a range between 100 nm and 300 nm;
a sensor; and
an optical system configured to direct the incident light onto a sample and direct light from the sample to the sensor,
wherein the light source includes a nonlinear optical crystal comprising:
a substrate comprising a hygroscopic nonlinear optical material and configured to convert incident light having a wavelength longer than 300 nm to output light having a wavelength between 100 nm and 300 nm; and
a first amorphous material layer disposed on the substrate,
wherein the first amorphous material layer forms a continuous encapsulating structure surrounding an outer surface of the substrate,
wherein the first amorphous material layer consists essentially of one or more alkali metal borates.