Patent Number: 6,251,549

Title: Generic phase shift mask

Abstract: The fine dark features in the images projected from strong phase-shifting masks used for microdevice lithography are accompanied by 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.

Inventors: Levenson; Marc David (Saratoga, CA)


International Classification: G03F 1/00 (20060101); G03F 009/00 (); G03C 003/00 (); G03C 005/00 ()

Expiration Date: 06/26/2018