Preparation of thermally stable TiO2-terminated SrTiO3(100) substrate surfaces

We have examined the thermal stability of TiO2-terminated SrTiO3(100) surfaces obtained by buffered HF etching and widely used as substrates for oxide film growth. In situ coaxial impact-collision ion scattering spectroscopy was used to measure the composition of the terminating atomic layer at temperatures up to 1000degreesC, simulating a broad range of thin-film growth conditions. The TiO2 termination of a nonannealed but HF-etched surface was found to start collapsing at temperatures as low as 300degreesC regardless of atmosphere, showing thermal instability of the chemically cleaved surface. Here, we introduce an alternative way to prepare a stabilized SrTiO3 surface, which maintains a perfect TiO2 termination up to 700degreesC, ideal for the growth of atomically sharp oxide heterointerfaces. (C) 2004 American Institute of Physics.