Microcontact printing of self-assembled monolayers: Applications in microfabrication

This paper describes applications in microfabrication using patterned self-assembled monolayers (SAMs) formed by microcontact printing. Microcontact printing (mu CP) is a flexible new technique that farms patterned SAMs with regions terminated by different chemical functionalities (and thus different physical and chemical properties), in patterns with mu m dimensions. Patterns of SAM are formed using an alkanethiol as an 'ink', and printing the alkanethiol on a metal support with elastomeric 'stamp'. We fabricate the stamp by moulding a silicone elastomer using a master prepared by optical or x-ray microlithography or by other techniques. SAMs of long-chain alkanethiolates on gold and other metals can act as nanometer resists by protecting the supporting metal from corrosion by appropriately formulated etchants: the fabrication of microstructures of gold and silicon demonstrates the utility of patterned SAMs (formed by mu CP) as nm resists. Patterned SAMs formed by mu CP can also control the wettability of a surface on the irm scale, The organization of liquids in patterned arrays with mu m dimensions, and the patterned deposition of microcrystals and microcrystal arrays illustrate the use of controlled wettability for microfabrication.