The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 24, 2004
Filed:
Nov. 15, 2002
Scientific System Research Limited, Kilbarrack, IE;
Abstract
A method of fault detection is described for use in a plasma process chamber powered by an RF source and subject to periodic standard preventive maintenance. Prior to a production run, the changes in magnitude of a plurality of Fourier components of the RF source resulting from known changes in a plurality of process conditions are determined and a single parameter which is a linear combination of a selected subset of said components is constructed. The construction is such that the combination is relatively sensitive to pre-selected process changes and relatively insensitive to said standard preventive maintenance. Then, during the production run, the single parameter is monitored to determine if there is a fault in the plasma process.