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:
Apr. 10, 2001
Filed:
May. 07, 1998
Charles Dornfest, Fremont, CA (US);
Anand Gupta, San Jose, CA (US);
Gerald Girard, Milpitas, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
An electrostatic technique for removing particulate matter from a semiconductor wafer in a plasma processing chamber, such as a plasma-enhanced chemical vapor deposition (PECVD) chamber. During a particulate removal phase of operation, a normally grounded electrode that supports the wafer is temporarily isolated from ground and a bias voltage generator is simultaneously connected to the electrode, supplying sufficient bias voltage to electrostatically launch particulates from the surface of the wafer. A plasma formed above the normally grounded electrode is maintained during the particulate removal phase, and particulates launched from the wafer become suspended in a sheath region surrounding the plasma, from where they can be later removed by a purging flow of gas. Preferably, the bias voltage generator provides a bias voltage that alternates in polarity, to ensure removal of both positively-charged and negatively charged particles from the wafer surface.