PREPARATION OF GOLD THIN-FILMS BY EPITAXIAL-GROWTH ON MICA AND THE EFFECT OF FLAME ANNEALING

Highly crystalline thin films of gold were grown on scratch-free mica: Epitaxial growth was accomplished by heating a fleshly cleaved 8 mmX8 mm piece of mica to 380 degrees C for 12 h at 1.9 X 10(-7) Torr, foll owed by gold deposition at 1 Angstrom/s and 380 degrees C until 100 ri m was deposited. After flame annealing, these gold films are observed to have grains that are on average 6300 Angstrom in width with a peak to peak topography of a few atomic layers. Adhesion of gold to mica wa s accomplished by controlling the temperature and length of bakeout in addition to the temperature of deposition. Films prepared in this man ner exhibited excellent adhesion when immersed in all solvents except water. The nearly universally [111] terminated gold films were charact erized by scanning tunneling microscopy (STM) and transmission electro n microscopy (TEM). STM imaging showed-that the gold surfaces exhibit the 22X root 3 reconstruction. Flame annealing of films removes contam inants. and increases the flat surface area by a factor of 25 relative to the unannealed films as was indicated by both STM and TEM. (C) 199 8 American Vacuum Society. [S0734-2101(98)00206-1].