Simplified fabrication methods for rim phase-shift masks

A method of increasing contrast of a lithography exposure mask having at least one optical feature thereon, said optical feature being at least one of an aperture and a phase shift structure, said method including the steps of

• depositing a layer of phase-shift material over said at least one optical feature, and
• establishing a rounding factor of said layer of phase shift material adjacent an edge of at least one said optical feature.

A phase-shift lithography mask for projecting at least one image area onto a resist material including

• a substrate which is substantially transparent to electromagnetic radiation having a desired wavelength and which has a first refractive index,
• a pattern of opaque material deposited on said substrate and having openings therein exposing said substrate and
• a feature corresponding in size to said at least one image area formed in at least one of said substrate and a layer of phase shift material which is substantially transparent to electromagnetic radiation having said desired wavelength and which has a second refractive index substantially equal to said first refractive index, said layer of phase shift material being deposited on said substrate, within said openings.

A method of fabricating a lithography exposure mask for exposing at least one area and including at least one feature including at least one phase shift region adjacent an opaque region of the mask, said method including the step of

• patterning a layer of opaque material deposited on a substrate in accordance with said at least one feature wherein said feature corresponds in size to said area and said phase shift region,
• conformally depositing a phase shift material over said opaque material and said substrate, and
• establishing a rounding factor of said phase shift material adjacent an edge of said opaque region.