Effects of rapid thermal annealing on the morphology and optical property of ultrathin InSb film deposited on SiO2/Si substrate

Abstract

Ultrathin InSb films on SiO2/Si substrates are prepared by radio frequency (RF) magnetron sputtering and rapid thermal annealing (RTA) at 300, 400, and 500 °C, respectively. X-ray diffraction (XRD) indicates that InSb film treated by RTA at 500 °C, which is higher than its melting temperature (about 485 °C), shows a monocrystalline-like feature. A high-resolution transmission electron microscopy (HRTEM) micrograph shows that melt recrystallization of InSb film on SiO2/Si (111) substrate is along the (111) planes. The transmittances of InSb films decrease and the optical band gaps redshift from 0.24 eV to 0.19 eV with annealing temperature increasing from 300 °C to 500 °C, which is indicated by Fourier transform infrared spectroscopy (FTIR) measurement. The observed changes demonstrate that RTA is a viable technique for improving characteristics of InSb films, especially the melt-recrystallized film treated by RTA at 500 °C.