Wafer-Scale Synthesis of Topological Insulator Sb2Te3 Thin Films

Recently, metal-organic chemical vapor deposition (MOCVD) has been proven successful to grow topological insulators such as antimony telluride (Sb2Te3), with their use as efficient spin-charge converters at room temperature also being reported. On the other hand, a wafer-scale synthesis of Sb2Te3 thin films showing clear-cut electrical conduction driven by topologically protected surface states is still missing. Within this work, the growth of Sb2Te3 thin films with variable thicknesses over 4-inch (4 '') wafer-scale Si(111) substrates as conducted via MOCVD is reported. By performing magnetoconductance measurements, weak antilocalization phenomena are detected over the whole 4 '' area, thus proving the possibility to produce wafer-scale Sb2Te3 topological insulator thin films. Furthermore, comprehensive information on the variability of the functional properties of Sb2Te3 thin films with their morphological, chemical, and structural properties, as probed by scanning electron microscopy, X-ray diffraction/reflectivity, atomic force microscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry, and energy-dispersive X-ray analyses is reported. This work provides a breakthrough for the technology scale-up of these novel materials to be employed in future spintronic devices as well as applications in nanoelectronics, thermoelectrics, and quantum computing.