US 12,078,547 B2
Etalon thermometry for plasma environments
Bruce E. Adams, Portland, OR (US); Samuel C. Howells, Portland, OR (US); Alvaro Garcia, Mountain View, CA (US); Barry P. Craver, Sunnyvale, CA (US); Tony Jefferson Gnanaprakasa, Mountain View, 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 Sep. 28, 2021, as Appl. No. 17/487,993.
Prior Publication US 2023/0102821 A1, Mar. 30, 2023
Int. Cl. G01J 5/58 (2022.01); H01J 37/32 (2006.01); H01L 21/66 (2006.01)
CPC G01J 5/58 (2013.01) [H01J 37/32522 (2013.01); H01L 22/12 (2013.01); G01J 2005/583 (2013.01); H01J 2237/24585 (2013.01); H01J 2237/334 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of sensing temperature suitable for use in a semiconductor processing chamber, the method comprising:
passing a first light beam through a first etalon;
passing the first light beam through a substrate disposed in the processing chamber, the substrate providing a second etalon;
generating a reflected second beam and a transmitted second beam from the first light beam after passing the reflected second beam through both of the first etalon and the second etalon;
determining fringe spacing from an interference pattern of one of the reflected second beam or the transmitted second beam;
determining a temperature of the substrate based on the fringe spacing; and
calibrating a substrate temperature sensor of the processing chamber using the temperature determined based on the fringe spacing of the interference pattern.
 
11. A method of sensing temperature suitable for use in a semiconductor processing chamber, the method comprising:
passing a first light beam through a first etalon;
passing the first light beam through a substrate disposed in the processing chamber, the substrate providing a second etalon;
generating a reflected second beam and a transmitted second beam from the first light beam after passing the reflected second beam through both of the first etalon and the second etalon;
determining fringe spacing from an interference pattern of one of the reflected second beam or the transmitted second beam; and
determining a temperature of the substrate based on the fringe spacing,
wherein before the determining the fringe spacing, the processing chamber and the substrate are brought to a steady state temperature and a thickness of the substrate is calculated using an initial substrate temperature measurement and a first thickness of the first etalon is adjusted to be within 10 μm of a second thickness of the substrate by moving the first etalon out of a path of the first light beam and placing an alternate first etalon in the path of the first light beam.