Crystal growth and characterization of topological insulator BiSb thin films by sputtering deposition on sapphire substrates

We report on the growth and characterization of BiSb thin films deposited on sapphire substrates by sputtering deposition with Ar and Kr plasma. By optimizing the growth conditions, we are able to obtain quasi-single-crystal BiSb(001) thin films with equivalent twin crystals. The conductivity of BiSb at the studied thicknesses exceeds 10(5) Omega(-1) m(-1), reaching 1.8 x 10(5) Omega(-1) m(-1) at 10 nm. From the temperature dependence of the electrical resistivity, we confirm the existence of metallic surface states. Our results demonstrate that it is possible to obtain sputtered BiSb thin films with quality approaching that of epitaxial BiSb grown by molecular beam epitaxy. (C) 2020 The Japan Society of Applied Physics