Photolithographic deposition of conducting gold films from thin amorphous films of AuPR3X (X = NO3, RCO2) on silicon surfaces

The photochemical reactions of amorphous films of AuPR3X (X = NO3, RCO2) on silicon surfaces are presented. In each case these precursors could be used to form amorphous thin films on silicon substrates by spin coating. The photolysis of these films was monitored by FTIR spectroscopy and the products analyzed by Auger electron spectroscopy. The photolysis with 254 nm light led to the loss of the anionic ligand from the film. The phosphine ligand also diffused from the film although far less efficiently. The purity of the contaminated films could be improved by a heat treatment at 150 degrees C. The films following this heat treatment were approximately 90 at.% gold. This process was then used to lithograph gold patterns on silicon surfaces. A feature size of 1.2 mu m was demonstrated. (C) 2000 Elsevier Science Ltd All rights reserved.