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DS: Fachverband Dünne Schichten

DS 30: Focus Session: Emerging oxide semiconductors II (jointly with HL, DF, O)

DS 30.10: Vortrag

Mittwoch, 2. April 2014, 18:00–18:15, POT 081

Electronic surface properties of stoichiometric and defect-rich indium oxide films prepared by MOCVD — •Marcel Himmerlich¹, Chunyu Wang², Volker Cimalla², Oliver Ambacher², and Stefan Krischok¹ — ¹Institut für Physik and Institut für Mikro- und Nanotechnologien, Technische Universität Ilmenau, PF 100565, 98684 Ilmenau, Germany — ²Fraunhofer-Institut für Angewandte Festkörperphysik, Tullastraße 72, 79108 Freiburg, Germany

The influence of metalorganic chemical vapor deposition conditions on the indium oxide surface properties is investigated using photoelectron spectroscopy (PES). It is shown that the growth conditions have a strong influence on the physical properties and that films prepared at 200^∘C or below are highly oxygen-deficient and rich in defects, influencing the surface chemical and electronic properties and resulting in the existence of excess electrons, which are partially localized at the remaining indium atoms. This configuration results in the existence of reactive defect sites, which cause high ozone sensitivity. The PES results are compared to the electronic properties of crystalline In₂O₃ films in cubic bixbyite and rhombohedral structure. The influences of the surface stoichiometry and high defect density, ozone oxidation and UV photoreduction on variations in surface band bending, electron accumulation, work function and formed surface dipoles as well electron transport and sensor characteristics are analyzed.