EXTENDING MICROCONTACT PRINTING AS A MICROLITHOGRAPHIC TECHNIQUE

This paper describes a number of approaches that have been employed to reduce the size of features of self-assembled monolayers (SAMs) gener ated using microcontact printing (mu CP). In mu CP, an elastomeric sta mp is used to print patterned SAMs of alkanethiolates on the surfaces of coinage metals and SAMs of alkylsiloxanes on Si/SiO2. It is a conve nient technique for generating patterned microstructures with feature sizes greater than or equal to 500 nm. The capability of this techniqu e could be extended to produce features smaller than 500 nm using the following approaches:. (1) mu CP with mechanical deformation of the el astomeric stamp--that is, with lateral compression or uniaxial stretch ing in the plane of the stamp and with pressure perpendicular to the p lane of the stamp; (2) mu CP with physical alternation of the elastome ric stamp--that is, with a stamp that has been swelled with a solvent or a stamp whose dimensions have been reduced by extraction of an iner t filler; (3) mu CP with reduction in the size of features resulting f rom processes taking place on the surface--that is, lateral reactive s preading of hexadecanethiol on gold; and (4) mu CP with multiple impre ssions on the same surface. The advantages and disadvantages of each a pproach are evaluated and compared in this paper.