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Title: Defect tolerant transmission lithography mask

Abstract

A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

Inventors:
 [1]
  1. Pleasanton, CA
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
873389
Patent Number(s):
6150060
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
G - PHYSICS G03 - PHOTOGRAPHY G03F - PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
defect; tolerant; transmission; lithography; mask; utilizes; transparent; substrate; partially; membrane; active; region; reflective; single; layer; multilayer; coating; deposited; surface; facing; illumination; selectively; patterned; removed; form; transmissive; bright; regions; structural; imperfections; defects; negligible; effect; aerial; image; master; pattern; reflect; radiation; entrance; pupil; imaging; similarly; influence; amplitude; phase; transmitted; electromagnetic; fields; discards; absorbs; unwanted; reduced; optical; absorption; thermal; loading; compared; conventional; designs; euv; applications; circumvents; independent; load; exposure; transparent substrate; membrane surface; multilayer coating; reduced thermal; electromagnetic fields; entrance pupil; optical absorption; single layer; electromagnetic field; active region; magnetic field; magnetic fields; transparent membrane; surface facing; reflect radiation; thermal loading; thermal load; reduced optical; transmission lithography; parent substrate; phase defect; lithography mask; /430/

Citation Formats

Vernon, Stephen P. Defect tolerant transmission lithography mask. United States: N. p., 2000. Web.
Vernon, Stephen P. Defect tolerant transmission lithography mask. United States.
Vernon, Stephen P. Sat . "Defect tolerant transmission lithography mask". United States. https://www.osti.gov/servlets/purl/873389.
@article{osti_873389,
title = {Defect tolerant transmission lithography mask},
author = {Vernon, Stephen P},
abstractNote = {A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}