USING MICROMACHINING, MOLECULAR SELF-ASSEMBLY, AND WET ETCHING TO FABRICATE 0.1-1-MU-M-SCALE STRUCTURES OF GOLD AND SILICON

A combination of molecular self-assembly and micromachining was used t o pattern the surface of thin films of gold with 0.1-1-mum-sized regio ns of monolayers formed from HO(CH2)2SH and CH3(CH2)15SH. Selective, w et chemical etching of gold supporting patterned, self-assembled monol ayers resulted in the formation of microstructures of gold on substrat es of silicon or glass. Using this procedure, it is possible to constr uct electrically conducting wires of gold with cross sections as small as 200 nm X 25 nm and lengths greater-than-or-equal-to 15 mum. Comple x and closely spaced microstructures, such as parallel and collinear w ires separated by <1 mum, can also be fabricated. Microstructures of g old served as masks for wet etching of silicon (aqueous solutions of 2 M KOH) and were used to form multilayer structures of gold and silico n. This method of microfabrication is a simple one, can be performed i n any wet chemical laboratory, and, we believe, can be scaled to small er dimensions.