Modeling of in-plane distortions due to variations in absorber stress

The effort to achieve sub-0.25 mu m X-ray lithography depends, in part, on the ability to maintain strict fabrication control leading to low distortion X-ray masks. This paper presents finite element (FE) models developed to identify sources of pattern in-plane distortions (IPD) during mask fabrication. In particular, mask fabrication processes inducing both uniform and non-uniform absorber stresses and the resulting distortions due pattern transferring through these stressed layers have been investigated.