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. 12, 2000
Filed:
Jan. 12, 1999
Glen T Mori, Pacifica, CA (US);
Daniel O Clawson, Mountain View, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
A method for reducing particulate generation from regeneration of cryogenic vacuum pumps. The method comprises controlling a pressure ramp rate inside the cryopump during an initial introduction of a regeneration gas into the cryopump. Preferably, the pressure ramp rate is controlled by maintaining a first pressure ramp rate, preferably between about 0.03 T/s and 0.15 T/s, until a first pressure of about 0.3 T is reached inside the cryopump and maintaining a second pressure ramp rate between about 1 T/s and 5 T/s until the surface in the cryopump reaches an intermediate temperature between about 40 K and 100 K. Preferably, the temperature ramp rate is also controlled by heating the surface at a temperature ramp rate between about 0.1 K/s and about 0.5 K/s until the intermediate temperature has been reached. Preferably, the temperature ramp rate is controlled by regulating the flow of an inert gas into the cryopump using a flow restriction device. Alternatively, the second stage cryoarray temperature is increased at the rate of between 0.1 K/s and 0.5 K/s using a PID controlled heater.