SCHOTTKY-BARRIER AND INTERFACE FORMATION OF METAL-GATE(001) INTERFACES

We studied the deposition of Au, In, Ag, and Al overlayers onto clean- cleaved GaTe(001) surfaces at room temperature by x-ray photoelectron spectroscopy. Gold and In overlayers did not produce evidence of chemi cal reactions, and neither with cation nor anion outdiffusion. Gold ov erlayers exhibited no evidence of island formation and a layer-by-laye r overlayer coverage. The deposition of In revealed the presence of cl ustering for a metal thickness higher than 6 Angstrom. On the other ha nd, the deposition of Al lead to an exchange reaction with a metallicl ike Ca phase separation. Core level analysis of the Ag-GaTe interface revealed no noticeable change of the shape of the peaks. The dependenc e of the peak intensities on overlayer thickness showed an initial lay er-by-layer coverage until 1.8 Angstrom, followed by a clustering grow th mode. From about 3.7 Angstrom Ag thickness, significant Te outdiffu sion was observed. (C) 1998 American Institute of Physics. [S0021-8979 (98)09516-4].