Skip to main content
Article thumbnail
Location of Repository

Alternative smoothing techniques to mitigate EUV substrate defectivity

By R. Teki, A.J. Kadaksham, M. House, J. Harris-Jones, A. Ma, S.V. Babu, A. Hariprasad, P. Dumas, R. Jenkins, J. Provine, A. Richmann, J. Stowers, S. Meyers, U. Dietze, T. Kusumoto, T. Yatsui, M. Ohtsu and F. Goodwin

Abstract

The majority of extreme ultraviolet (EUV) lithography mask blank defects originate from chemical mechanical polishing (CMP) of the substrate. The fact that CMP has not yet been able to yield EUV substrates with low defect counts highlights the challenges of polishing doped fused silica surfaces. Here we investigate alternative techniques based on processing either the substrate or coatings of amorphous silicon thin films and inorganic metal oxides. In particular, we evaluate a novel polymer-based non-abrasive a-Si CMP process, a photo-induced dry etching of substrate protrusions, a smoothing coat of spin-on or capillary coated Inpria metal oxide solution, CO2 laser polishing of the substrate surface, and annealing an a-Si thin film surface in reducing atmospheres. Although CMP still remains the best process with respect to overall process integration, these techniques have the potential to support CMP in solving the substrate defectivity issue and help pave the way to commercializing EUV mask blanks

Year: 2012
DOI identifier: 10.1117/12.916497
OAI identifier: oai:fraunhofer.de:N-209256
Provided by: Fraunhofer-ePrints
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://publica.fraunhofer.de/d... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.