Browse Prior Art Database

Microcontact Printing Alkanethiols on Au: A Consumable Ag Coat to Reduce Adversary Mass Transport of the Ink

IP.com Disclosure Number: IPCOM000122950D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 120K

Publishing Venue

IBM

Related People

Biebuyck, H: AUTHOR [+4]

Abstract

Microcontact printing (&mu.CP) is a technique that seeks to form chemical patterns on substrates. A particularly effective demonstration of this technique uses an elastomeric, patterned "stamp" inked by a dilute solution of an alkanethiol in ethanol to form a monolayer of the thiol on a gold substrate within the zones of print (1). The monolayer patterned on gold by this means can subsequently control an important range of phenomena occurring at the air/monolayer interface like the wetting, corrosion or chemical derivatization of the substrate (2). Patterning the substrate with high contrast in its chemical composition is important to control reliably the properties of the resulting interfaces. Dense and well ordered monolayers of alkanethiols 1.5 to 2.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Microcontact Printing Alkanethiols on Au:  A Consumable Ag Coat to
Reduce Adversary Mass Transport of the Ink

      Microcontact printing (&mu.CP) is a technique that seeks to
form chemical patterns on substrates.  A particularly effective
demonstration of this technique uses an elastomeric, patterned
"stamp" inked by a dilute solution of an alkanethiol in ethanol to
form a monolayer of the thiol on a gold substrate within the zones of
print (1).  The monolayer patterned on gold by this means can
subsequently control an important range of phenomena occurring at the
air/monolayer interface like the wetting, corrosion or chemical
derivatization of the substrate (2).  Patterning the substrate with
high contrast in its  chemical composition is important to control
reliably the properties of the resulting interfaces.  Dense and well
ordered monolayers of alkanethiols 1.5 to 2.5 nm thick behave as good
resists against etch of  the gold in a 'CN' sup - '/O' sub 2 bath,
for example (3).  Failure of  the strict localization of alkanethiol
molecules into the zones of contact results in adventitious
protection of the substrate against dissolution or retardation of its
dissolution by the etchant.  In particular, vapor pressures of
molecules in the ink can build up in the  cavities formed between
receded regions of the stamp and the substrate  and can provide a
supply of reactants to unprinted areas on the gold.  This problem is
often exacerbated in the system alkanethiols/gold  because the most
frequently used thiols are non polar with molecular weights between
200 and 300 g 'mol' sup <-1> and have a high sticking coefficient
with gold.  A simple solution to reduce or even suppress the  effect
of the ink volatility on the formation of etched patterns in gold
printed by &mu.CP is presented.  This solution uses the presence of a
silver adlayer on the gold substrate to exhaust unproductively
molecules that spreads outside the desired pattern.

      The gold pattern in the Figure produced by printing
HexaDecaneThiol (HDT) and etching the gold for 6 min in the cyanide
etch bath has a poor contrast because of an ubiquitous background
protection that interfered strongly with the etch.  A broadening is
also observable because the features developed in the gold are
enlarged in all directions by &tilde.  500 nm.  Mass transport of HDT
by...