Annealing Effects in Evaporated InSb Films

Abstract

The conductivity and Hall coefficient of evaporated InSb films 550 to 3750 Å thick have been monitored while the films were being annealed. It is found that the conductivity passes through a maximum during annealing, if the temperature is above 130°C. The Hall coefficient remains very small while films are annealed at temperatures below 200°C, but it rises rather abruptly at a fixed higher temperature, approaching some asymptotic value after several hours. Evidences of free In and Sb shown by electron and x-ray diffraction of unannealed films are no longer present after the films are annealed at 130°C. Electron microscope examination of carbon replicas reveals no gross differences between the surfaces of annealed and unannealed films and shows that the films are continuous. Annealed films of both conductivity types have been observed. At room temperature, carrier concentrations lie between 6×1015 and 4×1019/cm3 and Hall mobilities between 10 and 500 cm2/V sec. The mobility increases with increasing temperature over most of the range from 100 to 500°K; in a few cases it has passed through a maximum near the high temperature limit.