Thin-Film Growth and Characterization of InSb on Si by RF Sputter Deposition and Post-Annealing

Indium antimonide (InSb) is a promising material for infrared photodetectors owing to its narrow bandgap and high carrier mobility. In this study, InSb thin films were deposited on Si substrates by radio-frequency sputtering and their structural and electrical properties were investigated. The film thickness was controllable by adjusting deposition time, and annealing promoted crystallization of the films. Based on optimized conditions, n-InSb/p-Si pn-junction photodiodes were fabricated, exhibiting clear rectifying I–V characteristics and distinct photoresponse under illumination with infrared LEDs of 1310 and 1550 nm. These results demonstrate the potential of sputtering as a low-cost and scalable method for InSb-based infrared detectors.