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:
Jul. 11, 2000
Filed:
Jun. 12, 1998
Masahiro Aoki, Tokyo, JP;
Susumu Saito, Kofu, JP;
Tokyo Electron Limited, Tokyo, JP;
Abstract
An end-point detector for a plasma etcher, includes a converging lens for receiving strip-like plasma light produced between a pair of opposed electrodes and a spectroscope, having a slit located at a substantial rear-side focal plane of the converging lens, for detecting an etching end time point from a time-based variation of spectrum light intensity of the plasma light which has been converged at the slit and has passed through the slit. The converging lens has a pupil diameter of not greater than ##EQU1## where W is a width of a short side of the strip-like plasma light produced between the electrodes, 1 is a distance between an end of each electrode and a pupil face of the converging lens, NAm is a numerical aperture required by the spectroscope, and h is a width of a short side of the slit of the spectroscope. The converging lens has a numerical aperture of not less than NAm.