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:
Jun. 14, 1994
Filed:
Nov. 27, 1991
Tokyo Electron Limited, Tokyo, JP;
Abstract
A magnetron plasma etching apparatus comprises a chamber and a mount for supporting a substrate. A high-potential electrode connected to an RF power source is connected to the mount, and a low-potential electrode which is grounded is connected to the chamber. A rotary magnet is provided above the chamber, thereby generating a rotary magnetic field intersecting at right angles an electric field generated by both electrodes. An end-point detecting member for detecting an end-point of etching of the substrate is provided at the side of the chamber. The end-point detecting member collects mainly the light at a region near the rotation center of the magnetic field. That light component of a spectrum, which varies greatly with the progress of the etching, is extracted from the collected light, and the intensity of the light of this spectrum is converted to a first electric signal. The intensity of the collected light is converted to a second electric signal. The end-point detecting means calculates a ratio of the first and second electric signals, and the end-point of the etching is detected on the basis of the ratio.