p-Channel Oxide Thin Film Transistors Using Solution-Processed Copper Oxide

Abstract

Cu2O thin films were synthesized on Si (100) substrate with thermally grown 200-nm SiO2 by sol-gel spin coating method and postannealing under different oxygen partial pressure (0.04, 0.2, and 0.9 Torr). The morphology of Cu2O thin films was improved through N2 postannealing before O-2 annealing. Under relatively high oxygen partial pressure of 0.9 Tort, the roughness of synthesized films was increased with the formation of CuO phase. Bottom-gated copper oxide (CuxO) thin film transistors (TFTs) were fabricated via conventional photolithography, and the electrical properties of the fabricated TFTs were measured. The resulting Cu2O TFTs exhibited p-channel operation, and field effect mobility of 0.16 cm(2)/(Vs) and on-to-off drain current ratio of similar to 1 x 10(2) were observed in the TFT device annealed at P-O2 of 0.04 Torr. This study presented the potential of the solution-based process of the Cu2O TFT with p-channel characteristics for the first time.