In situ Monitoring of Composition and Sensitivity to Growth Parameters of Pulsed Laser Deposition

Complex oxide perovskites have been widely studied for their diverse functional properties. When dimensionally reduced to epitaxial thin films and heterostructures these properties are frequently tunable, and the symmetry-breaking inherent to thin film structures can result in the emergence of new, novel, phenomena and properties. However, the ability to control and harness these structures relies on an atomic-level understanding and control of the growth process, made challenging by the lack of suitable in situ compositional characterization tools. In this work, the compositional-dependence of SrTiO3 on pulsed laser deposition growth parameters is investigated with in situ Auger electron spectroscopy and ex situ thin film x-ray diffraction, and verified with a simple escape depth model. We show that this is a suitable technique for monitoring subtle compositional shifts occurring during the deposition process, with broad implications for the continued development of thin film synthesis techniques.