Thin film growth of a topological crystal insulator SnTe on the CdTe (111) surface by molecular beam epitaxy

• Published in: Journal of crystal growth 2016-11, Vol.453, p.124-129
• Main Authors: Ishikawa, Ryo, Yamaguchi, Tomonari, Ohtaki, Yusuke, Akiyama, Ryota, Kuroda, Shinji
• Format: Article
• Language: English
• Subjects: A1. Surface structure; A3. Molecular beam epitaxy; B1. Tellurides; B2. Topological crystalline insulators
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2016.08.027

We report molecular beam epitaxial growth of a SnTe (111) layer on a CdTe template, fabricated by depositing it on a GaAs (111)A substrate, instead of BaF2 which has been conventionally used as a substrate. By optimizing temperatures for the growth of both SnTe and CdTe layers and the SnTe growth rate, we could obtain SnTe layers of the single phase grown only in the (111) orientation and of much improved surface morphology from the viewpoint of the extension and the flatness of flat regions, compared to the layers grown on BaF2. In this optimal growth condition, we have also achieved a low hole density of the order of 1017cm−3 at 4K, the lowest value ever reported for SnTe thin films without additional doping. In the magnetoresistance measurement on this optimized SnTe layer, we observe characteristic negative magneto-conductance which is attributed to the weak antilocalization effect of the two-dimensional transport in the topological surface state. •SnTe (111) layers were grown on a CdTe template by molecular beam epitaxy .•The temperature for the growth of both SnTe and CdTe layers was optimized.•Single-phase SnTe layers with much improved surface morphology was obtained compared to the growth on BaF2.•A hole concentration as low as 1017cm−3 at 4K was achieved.•Magnetoresistance behaviors characteristic of the surface transport was observed.