Kinetics study of the GaP(110)/Cu interface via P L2,3VV Auger line shape and x-ray-photoemission spectroscopies

We have studied the evolution of the GaP(110)/Cu interface as prepared at room-temperature (RT) versus low-temperature (LT100 K) conditions. Electron-excited P L2,3VV and Cu M1VV Auger line shapes and x-ray-excited (h=1253.6 eV) Ga 2p3/2, Ga 3d, P 2p, Cu 2p3/2, and Cu 3p core-level emissions were followed as a function of the Cu coverage (2 up to 80). Regardless of the substrate temperature, substrate disruption is observed at 1 monolayer Cu, with P atoms participating in chemical bonds with deposited Cu. In parallel, the topmost Ga atoms are dislodged from their pristine locations and segregate in a metalliclike environment. These processes persist in the intermediate-coverage range (212 Cu) at both temperatures, being only relatively attenuated at LT. At very high Cu thicknesses, strong chemical intermixing and out-diffusion of substrate-derived species are still observed at RT, while these processes are nearly completely inhibited at LT. © 1990 The American Physical Society