US 11,854,767 B2
Measuring method and plasma processing apparatus
Masanori Sato, Miyagi (JP)
Assigned to TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Apr. 1, 2021, as Appl. No. 17/220,094.
Claims priority of application No. 2020-067730 (JP), filed on Apr. 3, 2020.
Prior Publication US 2021/0313146 A1, Oct. 7, 2021
Int. Cl. H01J 37/32 (2006.01); H01L 21/683 (2006.01)
CPC H01J 37/32082 (2013.01) [H01J 37/32449 (2013.01); H01L 21/6833 (2013.01); H01J 2237/24578 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A measuring method, comprising:
placing a substrate on an electrostatic chuck disposed inside a chamber;
attracting the substrate onto the electrostatic chuck;
generating plasma inside the chamber;
detecting an amount of light reflected at the substrate by light emission of the plasma;
performing spectroscopy with respect to a time-dependent change in the detected amount of light so as to detect an amount of light for each frequency; and
calculating a natural frequency of the substrate based on the amount of light for each frequency detected in the performing spectroscopy.