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. 19, 1978
Filed:
Dec. 29, 1975
Robert Gordon Poulsen, Ottawa, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
For plasma etching, to obtain high quality, accurate and reproducible results, the temperature of the plasma gas is measured, conveniently as close as possible to the articles to be etched, variations in the temperature from a desired datum being used to control the RF power supply and thus the RF power fed to the reaction chamber. Extremely quick and accurate control of temperature is provided and this provides accurate and reproducible control of etch rate. The rapid temperature response also enables a quick and accurate preheat cycle to be provided prior to the etching cycle. A particularly useful temperature measuring device is a gas thermometer, with a quartz capillary.