Structural and electronic characterization of antimonide films made by magnetron sputtering

Abstract

AlSb, GaSb and InSb films were deposited by magnetron sputtering on Si and SiO2/Si substrates and their electronic and structural properties were investigated as a function of film thickness and deposition temperature. Elemental composition and thickness were investigated by Rutherford backscattering spectrometry and particle induced x-ray emission analysis, while x-ray diffraction provided information about phase and structure. Surface chemical composition was investigated by x-ray photoelectron spectroscopy. Here we demonstrate that polycrystalline AlSb films can be produced by magnetron sputtering, where films deposited at 550 °C attain a zincblende phase and exhibit the smallest amount of oxygen (compared to other deposition temperatures). GaSb grown by this technique at room temperature holds an amorphous structure, with excess Sb, but for films deposited at 400 °C the structure is polycrystalline, stoichiometric with a zincblende phase. InSb films with a thickness of 75 nm and thinner, deposited at room temperature, are amorphous and for increasing thickness the films attain a zincblende phase with polycrystalline structure. Sputtering performed at elevated temperatures yields films with improved crystalline quality.