CPC H01J 37/32082 (2013.01) [H01J 37/32449 (2013.01); H01L 21/6833 (2013.01); H01J 2237/24578 (2013.01)] | 9 Claims |
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.
|