Phase-shift mask providing balanced light intensity through different phase-shift apertures and method for forming such phase-shift mask

Abstract

A photomask may include a patterned layer, a phase-shift layer adjacent the patterned layer, a first aperture, a second aperture, and a light-absorbing layer. The first aperture may allow light to pass through the patterned layer and the phase-shift layer and provide a first phase shift. The second aperture may allow light to pass through the patterned layer and the phase-shift layer and provide a second phase shift different than the first phase-shift. The light-absorbing layer may be disposed adjacent the first aperture and may include a light-absorbing material that reduces the intensity of light passing through the first aperture such that the intensity of light passing through the first aperture is substantially equal to the intensity of light passing through the second aperture.

Description

[0001] Cross References to Related Applications [0002] This application claims U.S. Provisional Patent Application entitled "Phase Shift Mask Providing Balanced Light Intensity Through Different Phase Shift Apertures and Method of Forming Such Phase Shift Mask" by Gong Chen et al., filed September 26, 2005 Priority of No. 60 / 613,343, the entire contents of which are hereby incorporated by reference. technical field [0003] The present invention relates generally to photomasks, and more particularly to phase shift masks that provide balanced light intensity through different phase shift apertures and methods of forming such phase shift masks. Background technique [0004] In a typical alternating aperture phase shift mask (AAPSM), the intensity of light transmitted through a 180 degree aperture is generally less than that transmitted through a 0 degree aperture because the 180 degree aperture is associated with an etched quartz structure. As a result, the...

AI Technical Summary

Problems solved by technology

However, etched portions of the substrate beneath the patterning layer can result in overhangs of the patterning layer that can break off during various processes such as aggressive cleaning processes, causing irreparable defects in the photomask

Also, in applications utilizing thin patterning layers such as the sub-300nm patterning layer used in sub-75nm node designs, the patterning layer may be easily delaminated, resulting in defective photomasks

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