FABRICATION OF 15 NM WIDE TRENCHES IN SI BY VACUUM SCANNING TUNNELINGMICROSCOPE LITHOGRAPHY OF AN ORGANOSILANE SELF-ASSEMBLED FILM AND REACTIVE ION ETCHING

Organosilane precursor molecules, here (aminoethylaminomethyl)phenethy ltrimethoxysilane, or PEDA, are chemisorbed onto a Si surface forming a monolayer thick film, These films are patterned using the scanning t unneling microscope to locally modify the chemical reactivity and are then used as a template for selective electroless plating of a thin Ni film. Reactive ion etching in a C2F6/O-2 mixture transfers this patte rn into the substrate. Improvement over previous lithographic performa nce is achieved by growing the films on a passivated and lightly oxidi zed Si surface, optimizing the patterning conditions, and improving th e metallization and etch chemistry. In this way, we have generated dee p trenches on the order of 15+/-4 nm width, with edge roughness of 3 n m. We believe this demonstrates the resolution limiting factors of thi s lithographic process. (C) 1996 American Institute of Physics.