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:
Jan. 03, 1989
Filed:
May. 15, 1987
John Schuur, San Jose, CA (US);
David L Willenborg, Dublin, CA (US);
Michael W Taylor, Oakland, CA (US);
Allan Rosencwaig, Danville, CA (US);
Therma-Wave, Inc., Fremont, CA (US);
Abstract
The subject invention relates to a method and apparatus for identifying and testing the location of areas of interest on a workpiece and specifically, unmasked areas on a semiconductor wafer. In the subject method, the surface of the wafer is scanned with a search beam of radiation. The power of the reflected search beam will be a function of the optical reflectivity of the surface of the sample. Since the optical reflectivity of the unmasked areas are different from the masked areas, the power measurement of the reflected search beam can be used to identify the location of areas to be measured. In the preferred testing procedure, an intensity modulated pump beam is used to periodically excite a region in the identified unmasked area. A probe beam is then directed within the periodically excited region and the periodic changes in the power of the reflected probe beam, induced by the pump beam, are measured to evaluate ion dopant concentrations or the effects of processing steps, such as etching, on the surface of the wafer.