Sputtered niobium: Epitaxial thin film growth on a-plane sapphire

This application note describes the growth of epitaxial Nb thin films by sputtering onto single crystal sub strates at high temperature in the Royce Deposition System. For sputter deposition onto a-plane sapphire substrates at 800◦C, a 65 nm Nb film shows strong bcc 110 structural ordering and a residual resistivity ratio of 30, consistent with an epitaxial microstructure. The sample has a superconducting Tc of 8.986 K. Epitaxial Nb has important applications for superconducting electronics, quantum technologies, and as a template for the epitaxial growth of further overlayers.