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:
Feb. 23, 1993
Filed:
Jul. 26, 1991
Peter C Jann, Santa Clara, CA (US);
Kenneth P Gross, San Carlos, CA (US);
Armand P Neukermans, Palo Alto, CA (US);
Tencor Instruments, Mountain View, CA (US);
Abstract
A surface inspection apparatus having multiple inspection stations to inspect a wafer for a number of characteristics. The wafer is placed on a chuck connected to a rack-and-pinion or equivalent system so that the wafer simultaneously rotates and translates under the fixed position of the inspection stations. A single light source may be used by all stations in turn. One station may be a particle detector with collection optics receiving a small select portion of the light scattered from the wafer surface. A second station may be a roughness detector with a collection system to direct a large portion of scattered light to a detector. A position sensitive detector may be used to determine the slope of the wafer surface at an inspection point when the wafer is not clamped to the chuck, giving a measure of surface deformation. These or other stations are positioned about either of two inspection points at which the beam from the light source may be directed. The inspection points are spaced one wafer radius apart to minimize the required wafer motion for a complete surface scan.