Solid-state recrystallization processes in Ni-GaAs and Pd-GaAs structures

Electron microscopy, reflection electron diffraction, and x-ray diffraction analysis are used to investigate solid-state recrystallization processes in the Ni-GaAs and Pd-GaAs structures at room temperature and during heat treatment in a hydrogen atmosphere. Contacts were produced by electrodeposition of the metal (Ni, Pd) onto the (111) A surface of a GaAs ingot. It is shown that physical and chemical reactions at Ni-GaAs and Pd-GaAs contacts occur even at room temperature, with the formation of chemical bonds between the metal and both gallium and arsenic. The phases formed at the contacts upon annealing in a hydrogen atmosphere correspond to those expected from the phase diagrams, and solid-state recrystallization occurs under the strong orienting influence of the substrate.