Browse Prior Art Database

Top Imaging Lithographic Technique Using Tetrathiafulvalene

IP.com Disclosure Number: IPCOM000105274D
Original Publication Date: 1993-Jul-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Aviram, A: AUTHOR [+4]

Abstract

A lithographic method using polymers that contain a repeating group such as tetrathiafulvalene, chemically bound to the polymer, has been described previously [*]. The paper outlines induction of solubility changes of the polymer, when subjected to X Ray radiation. Also, a recent TDB publication by the same authors, teaches that the monomer 2-x-cyano acrylate (x = an ester substituent), condenses and polymerizes preferentially in imaged areas and provides a barrier for RIE etching, resulting in a negative image resist. The current disclosure is based on the chemistry that operates in the above mentioned paper and disclosure with the addition of new and surprising information.

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Top Imaging Lithographic Technique Using Tetrathiafulvalene

      A lithographic method using polymers that contain a repeating
group such as tetrathiafulvalene, chemically bound to the polymer,
has been described previously [*].  The paper outlines induction of
solubility changes of the polymer, when subjected to X Ray radiation.
Also, a recent TDB publication by the same authors, teaches that the
monomer 2-x-cyano acrylate (x = an ester substituent), condenses and
polymerizes preferentially in imaged areas and provides a barrier for
RIE etching, resulting in a negative image resist.  The current
disclosure is based on the chemistry that operates in the above
mentioned paper and disclosure with the addition of new and
surprising information.

      Tetrathiafulvalene was dissolved in a solution of poly ( alpha
-methylstyrene ) in xylene at a ratio of 0.1:1:3.5.  The solution was
spin coated onto Si wafers and placed in a closed container together
with crystals of  CBr sub 4  for four hours at room temperature.
Following this treatment the film was exposed to 365 nm UV light and
a visible image appeared.  The wafer was placed in another container
together with vapors of the acrylate (Permabond 910) for three hours.
The imaged areas were coated with acrylate polymer while on the
unexposed portion of the wafer, considerable less acrylate was
grafted.  The resulting growth height differential was in excess of
1.5 micron, over a period of 3 hours.

      The...