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:
Nov. 12, 2002
Filed:
Sep. 06, 2001
Marc David Levenson, Saratoga, CA (US);
Other;
Abstract
The fine dark features in the images projected from strong phase-shifting masks used for microdevice lithography are accompanied by 180° shifts in the optical phase, produced by a topography pattern distinct from the pattern of apertures that define the bright features. A generic topography pattern can be formed on the substrate underlying a continuous opaque mask layer which subsequently is patterned with a device-specific array of apertures. When the image projected from a phase-shifting mask comprised of the generic topography pattern and the device-specific aperture pattern is combined with a device-specific image projected from an associated conventional photomask, the photoresist pattern that results corresponds to desired device layers with the imaging advantages of strong phase-shifting masks, but without the need for specific patterning of the topography pattern.