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US 7,732,227 B2Granted
Method and apparatus for wall film monitoring
AssigneeTokyo Electron Limited
InventorsEric J. Strang, Richard Parsons
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AssigneeTokyo Electron Limited
InventorsEric J. Strang, Richard Parsons
Estimating the term…
A wall film monitoring system includes first and second microwave mirrors in a plasma processing chamber each having a concave surface. The concave surface of the second mirror is oriented opposite the concave surface of the first mirror. A power source is coupled to the first mirror and configured to produce a microwave signal. A detector is coupled to at least one of the first mirror and the second mirror and configured to measure a vacuum resonance voltage of the microwave signal. A control system is connected to the detector that compares a first measured voltage and a second measured voltage and determines whether the second voltage exceeds a threshold value. A method of monitoring wall film in a plasma chamber includes loading a wafer in the chamber, setting a frequency of a microwave signal output to a resonance frequency, and measuring a first vacuum resonance voltage of the microwave signal. The method includes processing the wafer, measuring a second vacuum resonance voltage of the microwave signal, and determining whether the second measured voltage exceeds a threshold value using the first measured voltage as a reference value.
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:
Dependencies are inferred from the claim text.