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:
Oct. 16, 2001
Filed:
Oct. 05, 1998
Chartered Semiconductor Manufacturing Ltd., Singapore, SG;
Abstract
A method of fabrication an alignment mark in a semiconductor device. The method uses one mask to that has two functions (1) a reverse active areas mask to remove the oxide from over active areas in the device areas and (2) an alignment mark open mask that removes the oxide from over the alignment mark area. The mask improves chemical-mechanical polish performance in the cell areas by removing the oxide over the active areas. Another key feature of the invention is the spacing of the alignment mark trenches that ensures that the step distance between the top of the second insulating layer in the alignment mark trench and the top surface of the substrate is greater than 2000 Å. This insures that the alignment marks are readable.