05419988 is referenced by 8 patents and cites 4 patents.

A phase shift photomask and a photomask blank used to produce the same. A dry etching stopper layer, which is disposed between a substrate and a light-shielding layer or between the substrate and a phase shifter layer, is made of either a film mainly composed of tin oxide nitride, which has high etching selectivity and high permeability, or an alumina film formed by sputtering, followed by heat treatment carried out in an oxidizing atmosphere, thereby enabling the required overetching to be satisfactorily performed during etching of the phase shifter layer, and thus making it possible to effect precise phase control. In addition, it is possible to eliminate the occurrence of an in-plane transmittance distribution.

Title
Photomask blank and phase shift photomask
Application Number
8/102488
Publication Number
5419988
Application Date
August 5, 1993
Publication Date
May 30, 1995
Inventor
Yukio Iimura
Tokyo
JP
Wataru Goto
Tokyo
JP
Masahiro Takahashi
Tokyo
JP
Keiji Hashimoto
Tokyo
JP
Hiroshi Mohri
Tokyo
JP
Agent
Dellett and Walters
Assignee
Dai Nippon Printing
JP
IPC
G03F 9/00
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