FORMATION OF THE CESIX SI(111) INTERFACE

The deposition of thin Ce films on Si(111) and subsequent or simultane ous annealing leads to the formation of various structurally, electron ically, and chemically different CeSix phases, as revealed by scanning -tunneling microscopy, low-energy electron diffraction, and photoelect ron spectroscopy. Several phases can coexist on the same sample, and w ith increasing annealing temperatures larger homogeneous domains are o bserved. This behavior is assigned to a mismatch of the lattices of th e Si-rich CeSix bulk compounds with that of the Si(111) substrate surf ace, resulting at temperatures above 700 degrees C in the formation of a thin film of hexagonal CeSi1.67, which does not exist as a bulk com pound. (C) 1995 American Vacuum Society.