Fault classification in a plasma process chamber
AssigneeScientific Systems Research Limited
InventorsJohn Scanlan, Michael B. Hopkins
Life of this patent
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Abstract
A method of fault classification in a plasma process chamber powered by an RF source comprises initially running a plurality of different baseline plasma processes on the chamber. For each baseline process, the magnitudes of a plurality of Fourier components of delivered RF power are determined and stored as an impedance fingerprint for that baseline process. In the case of a fault, one or more of the baseline processes is repeated according to a predetermined decision tree to determine the current fingerprints and classify the fault by comparing the current fingerprints with the original fingerprints.
Claims10
A method of fault classification in a plasma process chamber powered by an RF source, comprising the steps of:
- a) running a plurality of different baseline processes on the chamber,
- (b) in respect of each baseline process, determining the magnitudes of a plurality of Fourier components of delivered RF power and storing the magnitudes as reference data for that baseline process, and
- c) when a fault is to be classified, repeating at least one of the said baseline processes according to a predetermined decision tree to classify the fault by comparing the current magnitudes of the said Fourier components with the corresponding reference data.
A method of comparing two plasma process chambers powered by an RF source, comprising the steps of:
- a) running a plurality of different baseline processes on one of the chambers,
- b) in respect of each baseline process, determining the magnitudes of a plurality of Fourier components of delivered RF power and storing the magnitudes as reference data for that baseline process,
- c) running at least one of the said baseline processes on the other chamber according to a predetermined decision tree to classify any differences between the chambers by comparing the current magnitudes of the said Fourier components with the corresponding reference data.
A computer-readable storage medium bearing program code adated in execution on a computer to perform the following steps on a plasma process chamber powered by an RF source:
- a) run a plurality of different baseline processes on the chamber,
- (b) in respect of each baseline process, determine the magnitudes of a plurality of Fourier components of delivered RF power and store the magnitudes as reference data for that baseline process, and
- c) when a fault on the chamber is to be classified, repeat at least one of the said baseline processes according to a predetermined decision tree to classify the fault by comparing the current magnitudes of the said Fourier components with the corresponding reference data.
Dependencies are inferred from the claim text.