US 11,965,798 B2
Endpoint detection system for enhanced spectral data collection
Pengyu Han, San Jose, CA (US); and Lei Lian, Fremont, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by APPLIED MATERIALS, INC., Santa Clara, CA (US)
Filed on Jun. 10, 2021, as Appl. No. 17/344,791.
Prior Publication US 2022/0397482 A1, Dec. 15, 2022
Int. Cl. G02B 6/04 (2006.01); G01B 11/06 (2006.01); G01M 11/02 (2006.01); G02B 6/136 (2006.01); G02B 27/00 (2006.01); G02B 27/30 (2006.01); G03F 7/00 (2006.01)
CPC G01M 11/0207 (2013.01) [G01B 11/0683 (2013.01); G02B 6/04 (2013.01); G02B 6/136 (2013.01); G02B 27/0025 (2013.01); G02B 27/30 (2013.01); G03F 7/70625 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An endpoint detection system comprising:
a light source component configured to generate incident light;
an optical bundle coupled to the light source component, the optical bundle comprising:
a center point;
a first set of optical fibers arranged around the center point, the first set of optical fibers comprising a first emitting optical fiber and a first receiving optical fiber, wherein the first emitting optical fiber is positioned at a pairing angle relative to the first receiving optical fiber around the center point; and
a second set of optical fibers arranged around the center point, the second set of optical fibers comprising a second emitting optical fiber and a second receiving optical fiber, wherein the second emitting optical fiber is positioned at the pairing angle relative to the second receiving optical fiber around the center point,
and wherein the first emitting optical fiber and the second emitting optical fiber are configured to receive the incident light from the light source component;
a collimator assembly coupled to the optical bundle, wherein the collimator assembly comprises an achromatic lens configured to:
responsive to receiving a first light beam of the incident light from the first emitting optical fiber, direct a first plurality of spectral components of the first light beam to a first portion of a substrate surface and a second plurality of spectral components of the first light beam to a second portion of the substrate surface, wherein the first portion is substantially the same as the second portion;
collect a first plurality of reflected spectral components of light and a second plurality of reflected spectral components of light from the substrate surface, the first plurality of reflected spectral components of light produced by the first plurality of spectral components directed onto the first portion of the substrate surface and the second plurality of reflected spectral components of light produced by the second plurality of spectral components directed onto the second portion of the substrate surface; and
transmit the first plurality of reflected spectral components and the second plurality of reflected spectral components to the first receiving optical fiber of the optical bundle;
a light detection component coupled to the optical bundle, wherein the light detection component is configured to receive the first plurality of reflected spectral components and the second plurality of reflected spectral components from the first receiving optical fiber; and
a processing device communicatively coupled to the light detection component, the processing device configured to determine a reflectance of the substrate surface based on the first plurality of reflected spectral components and the second plurality of reflected spectral components.