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:
Nov. 18, 1997
Filed:
Apr. 12, 1996
Applicant:
Inventors:
Harald A Enge, Sherborn, MA (US);
William A Lanford, Malden Bridge, NY (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
250309 ; 250297 ;
Abstract
Surface contamination of silicon wafers is detected by a combined beam-deflecting magnet and magnetic spectrometer system. Heavy ions are directed onto the surface of a silicon wafer through the beam-deflecting magnet, and ions back-scattered from contaminants in the surface of the wafer pass through the magnetic spectrometer onto a focal-plane detector. One or more Einzel lenses prevent ions back-scattered from the silicon in the wafer from reaching the detector.