A125 reactions proceed in a highly inhomogeneous m a n n e r and are characterized by special orientation relationships on specific crystallographic planes of the parent phase. Results are analyzed in terms of kinetic and thermodynamic arguments and compared with selected electrical characteristics.
Surface Science 168 (1986) 404-408 North-Holland, A m s t e r d a m
THERMALLY-INDUCED REACTIONS AT PI-GaAs JUNCTIONS A.CROS
U.A. CNRS 783, FacultO des Sciences de Luminy, DOpartement de Physique, Case 901, 13288 Marseille Cedex 9, France Received 10 June 1985; accepted for publication 21 June 1985 The solid-state reaction between a Pt layer and a G a A s substrate has been studied with Rutherford backscattering and X-ray photoemission spectroscopies. At 3811°C, there is formation of an outer layer of PtGa covered by a few layers of u n b o u n d As and an inner layer mostly composed of PtAs 2. At 55(l°C, PtGa, forms at the surface. Examination of the PtGa and PtGa~ valence bands reveals a strong interaction between Pt and Ga atoms which appears as a shift of the emission m a x i m u m to lower binding energy. This behaviour is very similar to what is observed in Ph_Si and PtSi.
Surface Science 168 (1986) 409-415 North-Holland, A m s t e r d a m
THE ADSORPTION OF OXYGEN ON lnP CLEAVED SURFACES A N D ITS INFLUENCE ON SCHOTTKY BARRIER PROPERTIES A. ISMAIL,
and L. LASSABATF;RE
Laboratoire d'Etudes des Surfaces, Interfaces et Composants, UA 04, 0787, U.S.T.L., Place Eugene Bataillon, 34060 Montpellier Cedex, France Received ll) June 1985; accepted for publication 17 July 1985
The modification of the electronic properties of cleaved InP surfaces induced by oxygen exposure and by Ag and AI deposits, and the effect of initial oxygen exposure on the Schottky contact properties are studied. Results show that oxygen action is high enough to mask the Ag or AI submonolayer effect and to reduce the effect of the nature of the metal on the diode properties.