Characterization of the SnO2 based thin film transistors with Ga, In and Hf doping.

: We investigated the effects of doping tin oxide thin film transistors (TFTs) with Ga, In, and Hf. The quantity of doping impurities added to the SnO2-TFT channel layer was as follows: Ga (6.3-21.4 at.%), In (9.6-55.6 at.%), and Hf (1.2-2.7 at.%). Hafnium and gallium doping of SnO2 thin film decreased the carrier concentration, possibly due to a decrease in field effect mobility, and reduced oxygen vacancy-related defects. Indium-doped SnO2-TFTs exhibited high performance with a high field-effect mobility of > 20 cm2 V(-1) s(-1). The current on/off ratio and the subthreshold swing of In-doped SnO2-TFTs was 1 x 10(9) and 0.5 V/decade, respectively. These results demonstrate that Ga, In, and Hf doping can effectively enhance the performance of SnO2-based TFT devices.