Quality Improvement by Annealing for Flash-evaporated Thin InSb Films

Thin InSb films were prepared at room temperature by a rapid vacuum evaporation (flash evaporation) method using indium antimonide compound as a source material. The characteristics of the films such as microstructure and electrical properties were investigated in terms of heat treatment procedure. The as-deposited InSb films were found to have polycrystalline structure, and their stoichiometry was much better at higher deposition rates. Their characteristics were strongly influenced by successive annealing. The evaporation of Sb from the film caused by annealing led to poor electrical properties of the films. In order to avoid the evaporation of Sb from the film, an attempt was made to cap an as-deposited film with SiO2 layer before annealing. The microstructures as well as the galvanomagnetic properties were improved by introducing such capped-annealing. The highest Hall mobility of 2.1×104 cm2/Vs was obtained in an InSb film of 1.0 \ thick, when it was prepared with a deposition rate of 10 nm/s and followed by capped-annealing at 773 K.