Patent ID: 7732227
Filing Date: 2010-06-08
Classification: G01B,H01J,H01L

Abstract:
1. A method of monitoring wall film in a plasma chamber, the plasma chamber including a multi-modal resonator, a power source coupled to the multi-modal resonator and configured to produce a microwave signal, and a detector coupled to the multi-modal resonator configured to provide at least one of transmitted measurement data and reflected measurement data, said method comprising: loading a wafer in the plasma chamber; setting a frequency of a microwave signal output from the power source to a resonance frequency at which the microwave signal resonates in the plasma chamber; measuring a first vacuum resonance voltage of the power source corresponding to the resonance frequency of the microwave signal within the plasma chamber without plasma; processing the wafer; measuring a second vacuum resonance voltage of the power source corresponding to a change in the resonance frequency of the microwave signal within the plasma chamber without plasma and after the processing the wafer; and determining whether the second measured vacuum resonance voltage exceeds a threshold value using the first measured vacuum resonance voltage as a reference value.