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. 04, 1997
Filed:
Oct. 06, 1995
Ellen R Laird, San Jose, CA (US);
W Murray Bullis, Sunnyvale, CA (US);
James J Greed, Jr, Los Gatos, CA (US);
Bradley W Scheer, San Jose, CA (US);
VLSI Standards, Inc., San Jose, CA (US);
Abstract
A calibration target for topographic inspection instruments, operating at sub-micrometer resolution levels, having features on the order of 10 Angstroms in vertical height, an atomic scale distance. The features are formed on a silicon substrate, such as a wafer, by deposition of a thick oxide, such as a typical thermal oxide, over the wafer surface. A pattern of features is patterned and etched to the level of raw silicon at the wafer surface. Areas which have been etched are converted to a thin oxide, which slightly lowers the level of silicon in these areas. All oxide is removed and the slightly lower level of silicon gives rise to features having atomic scale vertical topographic dimensions. Millions of such features are produced simultaneously on a wafer to mimic the effect of haze or micro-roughness on a polished wafer.