Electrically Tunable Wafer-Sized Three-Dimensional Topological Insulator Thin Films Grown by Magnetron Sputtering

TL;DR

This paper demonstrates the rapid, low-cost fabrication of wafer-sized 3D topological insulator thin films on amorphous substrates via magnetron sputtering, enabling electrical tuning and exploration of topological phenomena for device applications.

Contribution

It introduces a scalable magnetron sputtering method to produce high-quality, large-area TI films with controllable properties on amorphous substrates, advancing practical device integration.

Findings

Successful growth of wafer-sized Bi2Te3 and magnetic TI films.

Electrical tuning of TI films between p-type and n-type.

Observation of topological surface state phenomena like QAHE.

Abstract

Three-dimensional (3D) topological insulators (TIs) are candidate materials for various electronic and spintronic devices due to their strong spin-orbit coupling and unique surface electronic structure. Rapid, low-cost preparation of large-area TI thin films compatible with conventional semiconductor technology is key to the practical applications of TIs. Here, we show that wafer-sized Bi2Te3 family TI and magnetic TI films with decent quality and well-controlled composition and properties can be prepared on amorphous SiO2/Si substrates by magnetron cosputtering. The SiO2/Si substrates enable us to electrically tune (Bi1-xSbx)2Te3 and Cr-doped (Bi1-xSbx)2Te3 TI films between p-type and n-type behavior and thus study the phenomena associated with topological surface states, such as the quantum anomalous Hall effect (QAHE). This work significantly facilitates the fabrication of TI-based devices for electronic and spintronic applications.