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:
Aug. 31, 1999
Filed:
Jul. 15, 1997
Christian Beyer, Cologne, DE;
Keith Trenton, San Jose, CA (US);
Mariusch Gregor, Cologne, DE;
Robert Stolle, Cologne, DE;
Rudolph Bahnen, Roedgen, DE;
Anja Plugge, Solingen, DE;
Heinz Frings, Cologne, DE;
Karl-Heinz Ronthaler, Zuelpich, DE;
Dennis Smith, San Jose, CA (US);
Jayesh Patel, Fremont, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Leybold Vacuum GmbH, Cologne, DE;
Abstract
A pressure for a chamber is regulated by controlling either the exhaust pressure at the exhaust side of a first vacuum pump or the internal pressure at a compression stage of the first vacuum pump, where the first vacuum pump is directly communicating with the chamber. The pressure of the chamber can be regulated by combinations of the following: controlling the variable rotational frequency of a roots vacuum pump, a pre-vacuum pump, or a high compression pump; controlling a control valve between a pre-vacuum pump and the first vacuum pump; controlling a control valve for injecting gas into the exhaust side of the first vacuum pump or into the compression stage of the first vacuum pump; and controlling a control valve or control valves for bypassing the first vacuum pump or a compression stage or compression stages of the first vacuum pump. To regulate the pressure in the chamber, several types of control rules can be used, including: a PID control rule, a gain scheduler, and a threshold comparison control rule.