Oxidation effects on InAs/GaSb (100) films deposited by DC magnetron sputtering during post-annealing.

Polycrystalline InAs films were prepared on GaSb substrates using direct current (DC) magnetron sputtering. The effects of different substrate temperatures, sputtering power, annealing methods, and annealing temperatures on the film structure and morphology were studied using XRD, Raman spectroscopy, XPS, UPS, SEM, EDS, and HRTEM. The results confirmed the formation of polycrystalline InAs films with a (111) crystal orientation on GaSb substrates. It was found that excessively high substrate temperatures lead to Sb diffusion, and high sputtering power introduces defects, which deteriorate the crystallinity of InAs films. InAs films with good crystallinity were achieved at a substrate temperature of 450 °C and a sputtering power of 90 W. Comparing the annealing methods, rapid thermal annealing (RTA) effectively suppresses the diffusion of Sb. XPS and EDS analyses indicated that annealing causes significant diffusion of Ga and Sb from the GaSb substrate, leading to the formation of oxides such as InSb, SbO 2 , In 2 O 3 , and As 2 O 3. The decomposition of the oxide layer on the substrate surface at 600 °C exacerbates the oxidation of the film. • Polycrystalline InAs films were prepared on GaSb substrates using magnetron sputtering. • Substrate temperature and sputtering power influence the crystallinity of InAs films. • High temperatures (>600 °C) decompose surface oxides on the substrate, exacerbating film oxidation. • The diffusion of Sb and Ga was confirmed, resulting in the formation of InSb and SbO 2. [ABSTRACT FROM AUTHOR]