Berlin 2018 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 10: Oxide Semiconductors for Novel Devices (Focussed Session): Session II

DS 10.1: Vortrag

Montag, 12. März 2018, 15:00–15:15, E 020

Defect and interface formation in SrTiO₃ homoepitaxial thin film growth — •Laura Bogula, Toni Markurt, Martin Albrecht, and Jutta Schwarzkopf — Max-Born-Str. 2, 12489 Berlin, Germany

SrTiO₃ represents a model system for perovskite materials and is therefore in the focus of fundamental research. Despite many studies, its functional properties and the correlation to atomic defects are not fully understood so far. Moreover, in many SrTiO₃ based devices next to the structural quality of the epitaxial film itself also the interface between substrate and film plays a crucial role. Therefore, we have performed a systematic investigation of the influence of different growth and pre-growth conditions on the resulting interface and the structural quality of homoepitaxial films grown by pulsed laser deposition (PLD). Transmission electron microscopy and x-ray diffraction techniques as well as reflection high-energy electron diffraction are applied to characterize films and interfaces. By varying substrate temperature, chamber pressure and oxygen content the optimal growth conditions for a stoichiometric, point defect-poor interface and film structure are specified. We found that on the one hand a high oxygen partial pressure during heat-up prior to film growth leads to an unfavourable surface reconstruction of the substrate causing a non-stoichiometric substrate/film interface. On the other hand, the formation of point defects in the film is correlated to the energetic ion bombardment during film growth which is reduced with a high process pressure.