Theoretical analysis of placement error due to absorber pattern on extremeultraviolet lithography mask

Citation
A. Chiba et al., Theoretical analysis of placement error due to absorber pattern on extremeultraviolet lithography mask, JPN J A P 1, 40(6A), 2001, pp. 3947-3952
Citations number
5
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Volume
40
Issue
6A
Year of publication
2001
Pages
3947 - 3952
Database
ISI
SICI code
0021-4922(200106)40:6A<3947:TAOPED>2.0.ZU;2-6
Abstract
The pattern placement accuracy of an extreme ultraviolet lithography (EUVL) mask strongly depends on the stresses present in the multilayer and absorb er films, since film stress causes both out-of-plane and in-plane distortio ns. To analyze this elastic deformation, we have developed simulation model s that handle the interaction between the multilayer and absorber patterns. The models are based on two-dimensional theories of bending plates and pla ne stress. The numerical calculations employ the finite difference method a nd the successive over-relaxation method. To examine the validity and accur acy of the models, the deformation of EUVL masks using simple absorber patt erns was calculated. For the calculations, we assumed a standard 6 inch qua rtz substrate with a reflective coating. The influence of the absorber patt ern on placement error was investigated by simulations. and it was found th at the absorber pattern is the main factor determining the pattern placemen t accuracy of an EUVL mask.