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:
Aug. 10, 1999
Filed:
Dec. 23, 1997
Eiichiro Kakehashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A formation method of an alignment mark is provided. After an etching resist part is formed on a first dielectric layer, a second dielectric layer is formed on the first dielectric layer to cover the etching resist part. Then, the second dielectric layer is selectively etched to form a recess uncovering the etching resists part using a first patterned lithography resist film as a mask. In this etching process, the first dielectric layer is prevented from being etched in the recess of the second dielectric layer by the etching resist part. A layer to be patterned is formed on the second dielectric layer and a second patterned lithography resist film is formed on the layer to be patterned. The second patterned lithography resist film has such a shape that a part of the second lithography resist film is left in the recess of the second dielectric layer. The part of the second lithography resist film in the recess has a height difference approximately equal to or less than the thickness of the second dielectric layer from another part of the second lithography resist film outside the recess. The alignment error of a pattern of the second lithography resist film with respect to a pattern of the second dielectric layer is measured correctly.