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:
Jul. 25, 1989
Filed:
Feb. 11, 1988
Walter Huber, Sunnyvale, CA (US);
DNS Electronic Materials, Inc., Research Triangle Park, NC (US);
Abstract
The concentration of internal gettering sites within a semiconductor wafer is controlled by two-step thermal processing. In a concentration reduction phase, the wafer is rapidly heated to an elevated temperature in the range from about 900.degree. to 1350.degree. C., resulting in the partial or total dissolution of precipitable impurities within the wafer. In a concentration enhancement step, the wafers are subjected to a relatively low temperature anneal process where the density of potential internal gettering sites is increased. By properly controlling the processing temperatures and treatment times, the two steps may be performed in either order to obtain wafers having internal gettering site concentrations within a desired range.