An ion-assisted Mo-Si deposition process for planarizing reticle substrates for extreme ultraviolet lithography

Author

Mirkarimi, Paul B. ; Spiller, Eberhard A. ; Stearns, Daniel G. ; Sperry, Victor ; Baker, Sherry L.

Author_Institution

Lawrence Livermore Nat. Lab., Berkeley, CA, USA

Volume

37

Issue

12

fYear

2001

fDate

12/1/2001 12:00:00 AM

Firstpage

1514

Lastpage

1516

Abstract

Substrate particles are a serious concern in the fabrication of reticles for extreme ultraviolet lithography (EUVL) because they nucleate defects in the reflective multilayer films that can print in the lithographic image. We have developed a strategy for planarizing reticle substrates with smoothing-layers and, in this letter, we investigate the smoothing properties of an ion-assisted Mo-Si deposition process. We have observed that ion-assistance can significantly improve the particle-smoothing properties of Mo-Si multilayer films and can do so without a significant increase in the high-spatial frequency roughness of the multilayer film. An ion-assisted Mo-Si smoothing-layer approach to reticle substrate planarization, therefore, shows significant promise for defect mitigation in EUVL reticles

Keywords

X-ray lithography; ion beam assisted deposition; molybdenum; optical fabrication; optical multilayers; reticles; silicon; substrates; ultraviolet lithography; EUVL reticles; Mo-Si; Mo-Si multilayer films; extreme ultraviolet lithography; high-spatial frequency roughness; ion-assistance; ion-assisted Mo-Si deposition process; lithographic image; particle-smoothing properties; planarizing; reflective multilayer films; reticle substrate planarization; reticle substrates; smoothing-layers; Coatings; Ion beams; Ion sources; Lithography; Nonhomogeneous media; Optical films; Smoothing methods; Sputter etching; Substrates; Ultraviolet sources;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.970896

Filename

970896