Work Function Optimization Technology of Indium Tin Oxide Films

Indium tin oxide (In₂O₃:Sn) film is one of the most potential materials in the field of semiconductor industry. However, untreated In₂O₃:Sn film has a low work function which can result in a high energy barrier that hinders the passage of carriers through the interface, thus leading to poor overall performance of directly prepared devices. In this study, crystalline transparent conductive In₂O₃:Sn films were prepared by plasma exposure assisted magnetron sputtering under room temperature. Based on multiple testing methods, it can be found that the low temperature crystallization characteristics of In₂O₃:Sn film were enhanced and the work function was effectively improved after Ar⁺ plasma exposure. The increase of the work function of In₂O₃:Sn film was due to the increment of Sn-O bond on the surface brought by the transition from low oxidation state Sn²⁺ to high oxidation state Sn⁴⁺ under the action of high exposure.