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:
Mar. 28, 2006
Filed:
Oct. 01, 2002
Wei E. Wu, Austin, TX (US);
Bernard J. Roman, Austin, TX (US);
Wei E. Wu, Austin, TX (US);
Bernard J. Roman, Austin, TX (US);
Freescale Semiconductor, Inc., Austin, TX (US);
Abstract
A photomask and a method for making the same in which an opaque feature () is formed on a transparent substrate () and a depression () is etched in the transparent substrate () adjacent to the opaque feature (). The depression () is etched to a depth such that a phase difference between light passing through the substrate () outside the depression () and light passing through the depression is 180°. In one embodiment, the depression () is formed in the substrate directly adjacent to an edge of the opaque feature (). In another embodiment, the depression () surrounds a mesa structure () formed in the substrate (), and the opaque feature () resides on the mesa structure (). The depression () may be laterally spaced from an edge of the opaque feature ().