Synopsys, Inc.
Undercut EUV absorber reflective contrast enhancement

Abstract:

An EUV mask absorber formed on a semiconductor structure, includes, in part a sidewall forming am angle relative to a surface of the semiconductor structure that is less than 90 degrees. The sidewall includes a layer of reflective material. The semiconductor structure may include, in part, a multitude of layers. The semiconductor structure may be disposed on a glass substrate, a silicon substrate, or the like. The EUV mask absorber is adapted to shift a phase of the EUV light passing therethrough. The EUV mask absorber may further include, in part, a layer of Ruthenium near a bottom surface of the absorber structure. The EUV mask absorber may further includes, in part, a layer of reflective material near a top surface of the absorber structure. The EUV mask absorber may further include, in part, Tantalum Oxynitride.