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:
Oct. 31, 1995
Filed:
Jul. 08, 1993
Boris Fishkin, San Jose, CA (US);
Phil Salzman, San Jose, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
An improved particle monitoring sensor is described which uses a variety of techniques to prolong the effective life of the optical surfaces within the particle monitoring sensor. Substantially inert purging gas is directed over the particle monitoring sensor windows, which are normally exposed to a harsh operating environment. The surfaces of these windows are heated by heating elements in direct thermal contact with the windows. In addition, a restrictive slit is placed over the detector window to reduce the exposed area and to increase the velocity of gas flowing over the window surface. While this slit reduces the detector's field of view, the signal loss is reduced by using a linearly polarized light source and aligning the elongated slit's major axis with the direction of polarization.