Indium oxide thin‐film transistor by reactive ion beam assisted deposition

This work reports on the fabrication and characterization of indium oxide semiconducting films and their application in thin‐film transistors (TFTs). The films have been deposited at room temperature by oxygen ion beam assisted e‐beam evaporation. The influence of deposition conditions on film properties including the crystal structure, conductivity, and intrinsic stress is analyzed. It is found that the electrical properties of indium oxide films can be engineered from metallic to insulating and the film structure can be varied from amorphous to microcrystalline by adjusting deposition rate, oxygen ion energy, and ion beam flux. Furthermore, the highly‐resistive films with considerable microstructural crystallinity exhibit n‐type field‐effect behaviour. A field‐effect mobility of 1.4 cm2/V s, and ON/OFF current ratio of ∼106 are observed for transistors with a silicon dioxide gate dielectric. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)