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:
May. 11, 1999
Filed:
Sep. 08, 1997
James D Bernstein, Beverly, MA (US);
Brian S Freer, Medford, MA (US);
Peter L Kellerman, Essex, MA (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A plasma-enhanced electron shower (62) for an ion implantation system (10) is provided, including an extension tube (66) having a replaceable graphite inner liner (88). The inner liner is biased to a low negative potential (-6 V) to prevent low energy secondary electrons generated by the electron shower target from being shunted away from the wafer, keeping them available for wafer charge neutralization. The electrically biased inner surface is provided with serrations (126) comprising alternating wafer-facing surfaces (128) and target-facing surfaces (130). During operation of the electron shower (62), photoresist or other material which may sputter back from the wafer collects on the wafer-facing surfaces (128), rendering them non-conductive, while the target-facing surfaces (130) remain clean and therefore conductive. The conductive target-facing surfaces provide a shunt (low resistance) path to electrical ground for high energy electrons generated in the electron shower.