THIN GOLD AND INDIUM FILMS ON SI(111) SURFACE

A 3-component system (Au-In-Si) and thin indium and gold film interactions on the Si(111)7 x 7 surface were examined using Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). A new surface phase Si(111)3 x 1-(Au, In) was detected at submonolayer metal coverages. Gold and indium were deposited under UHV conditions with further annealing at 300-500-degrees-C. It was shown that the agglomeration of gold atoms into islands covered by indium atoms takes place upon deposition of in onto the Si(111)5 x 1-Au surface phase with further annealing. This explains the absence of the gold Auger-peak (69 eV). Indium atoms in excess with respect to the Si(111)1 x 1-In surface phase are responsible for the Si-Au surface phase decay and for the formation of gold islands covered by indium.