Method for fabricating an ultra-low expansion mask blank having a crystalline silicon layer

Patent · Tue Jan 01 00:00:00 EST 2002

OSTI ID:874336

Cardinale, Gregory F ^[1]

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1. Oakland, CA

A method for fabricating masks for extreme ultraviolet lithography (EUVL) using Ultra-Low Expansion (ULE) substrates and crystalline silicon. ULE substrates are required for the necessary thermal management in EUVL mask blanks, and defect detection and classification have been obtained using crystalline silicon substrate materials. Thus, this method provides the advantages for both the ULE substrate and the crystalline silicon in an Extreme Ultra-Violet (EUV) mask blank. The method is carried out by bonding a crystalline silicon wafer or member to a ULE wafer or substrate and thinning the silicon to produce a 5-10 .mu.m thick crystalline silicon layer on the surface of the ULE substrate. The thinning of the crystalline silicon may be carried out, for example, by chemical mechanical polishing and if necessary or desired, oxidizing the silicon followed by etching to the desired thickness of the silicon.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-94AL85000
• Assignee: EUV LLC (Santa Clara, CA)
• Patent Number(s): US 6368942
• OSTI ID: 874336
• Country of Publication: United States
• Language: English

Related Subjects

method
fabricating
ultra-low
expansion
mask
blank
crystalline
silicon
layer
masks
extreme
ultraviolet
lithography
euvl
ule
substrates
required
thermal
management
blanks
defect
detection
classification
obtained
substrate
materials
provides
advantages
ultra-violet
euv
carried
bonding
wafer
thinning
produce
5-10
mum
thick
surface
example
chemical
mechanical
polishing
oxidizing
followed
etching
thickness
extreme ultraviolet
silicon substrate
ultraviolet lithography
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