Nanostructuring of alkanethiols with ultrasharp field emitters

Abstract

We have investigated the electron beam exposure of self-assembled monolayers (SAM) of alkanethiols on gold. SAM resist systems are of growing interest for proximal probe lithography due to their high chemical selectivity though being as thin as a monolayer. For this purpose a custom built proximal probe lithography device was used. The electrons emanate from an ultrasharp tungsten tip, providing extraordinary field emission properties—small emission angle and low emission energy. In contrast to common scanning tunneling microscope (STM) lithography our system can be operated not only in tunneling mode, but also in true field emission mode, i.e., at much larger tip-to-sample distances (typically 10–100 nm). Therefore the latter mode allows much higher writing speeds, as the tip does not have to follow the sample topography as accurately as in the STM mode. The first results obtained by exposure in the field emission mode are presented.