Method and apparatus for endpoint detection using partial least squares

Abstract

An apparatus and method for detection of a feature etch completion within an etching reactor. The method includes determining a correlation matrix by recording first measured data regarding a first etch process over successive time intervals to form a first recorded data matrix (110), assembling a first endpoint signal matrix using target endpoint data for a specific etch process, performing a partial least squares analysis (130) on the recorded data matrix and the first endpoint signal matrix to refine the recorded data matrix, and computing a correlation matrix (180) based upon the refined recorded data matrix and the first endpoint signal matrix. The method further includes performing a second etch process to form a second recorded data matrix. The correlation matrix and the second recorded data matrix are analyzed to determine whether an endpoint of the second etch process has been achieved.

Description

[0001] Cross References to Related Applications

[0002] This application claims priority to U.S. Application Serial No. 60 / 277,981, filed March 23,2001. The content of this application is hereby incorporated by reference. technical field

[0003] The present invention relates generally to endpoint detection in semiconductor manufacturing processes. Background technique

[0004] The present invention recognizes the problems associated with conventional fabrication of reaction chambers and methods of using those chambers, which are addressed by the use of the present invention.

[0005] Typically, during semiconductor processing, material is removed or etched along fine lines or in vias or contacts patterned on a silicon substrate using a (dry) plasma etch process. A plasma etch process generally involves positioning a semiconductor substrate with an overlying patterned protective layer, such as a photoresist layer, in a processing chamber. Once the substrate is positioned...

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