Consequences of plasma oxidation and vacuum annealing on the chemical properties and electron accumulation of In₂O₃ surfaces

Theresa Berthold¹, Julius Rombach² Thomas Stauden¹ Vladimir Polyakov³
Volker Cimalla³ Stefan Krischok¹ Oliver Bierwagen² and Marcel Himmerlich^1
1 Institut fur Mikro- und Nanotechnologien MacroNano, Technische Universit€at Ilmenau, PF 100565, 98684 Ilmenau, Germany
² Paul-Drude-Institut fur Festk€orperelektronik, Hausvogteiplatz 5–7, 10117 Berlin, Germany
³ Fraunhofer-Institut fur Angewandte Festk€orperphysik, Tullastraße 72, 79108 Freiburg, Germany
Journal of Applied Physics 120, 245301 (2016)

Indium Oxide (In₂O₃) is used for metal contacts of electronic devices. It is known that defects (oxygen vacancies) and impurities (adsorbates) of In₂O₃ films change electron concentration. In previous papers, surface treatment techniques using plasma technologies were investigated to reduce the defects and impurities of In₂O₃ films.

In this paper, Samco ICP plasma etching tool at Paul-Drude-Institut was used for plasma surface oxidation of In₂O₃, and the samples were treated by subsequent vacuum annealing. It was found that oxygen plasma treatment reduced adsorbed carbon impurities and removed surface defect states, attributed to oxygen vacancies.