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:
Sep. 28, 1999
Filed:
Jun. 17, 1998
Hiroyuki Ishihara, Yamanashi-ken, JP;
Kohei Kawamura, Yamanashi-ken, JP;
Tokyo Electron Yamanashi Limited, Nirasaki, JP;
Abstract
A susceptor on which a wafer is placed, and an upper electrode are arranged in the processing chamber of an etching apparatus to oppose each other. An optical transmission window is disposed in the side wall of the processing chamber. The upper electrode and the susceptor are supplied with RF powers from a second RF power supply and a first RF power supply, respectively, to excite a plasma in the processing chamber. Emission of the plasma is detected by an optical detector through the optical transmission window, and data is sampled. In a CPU, the sampling data is subjected to fitting based on the Weibull distribution function, thus obtaining an approximate equation, and furthermore the differential equation of the approximate equation is obtained. The virtual end point of etching is expected from the approximate equation and differential equation.