Thin-film transistors with transparent amorphous zinc indium tin oxide channel layer

Thin-film transistors ( TFTs) with transparent amorphous zinc indium tin oxide ( ZITO) channel layer are demonstrated. Optical transmission of the channel layer is approximately 85% in the visible portion of the electromagnetic spectrum. The channel layer is formed via rf magnetron sputter deposition and then furnace annealed in air. Peak incremental mobilities of 5 - 19 cm(2) V-1 s(-1) and turn-on voltages of - 4 to - 17V are obtained for devices annealed post-deposition at 100 - 300 degrees C, respectively. Current - voltage measurements indicate n-channel, depletion-mode transistor operation with excellent drain current saturation and a drain current on-to-off ratio greater than 10(6). ZITO is one example of an emerging class of high performance TFT channel materials involving transparent amorphous multicomponent oxides composed of heavy-metal cations with ( n - 1) d(10)ns(0) ( n >= 4) electronic configuration.