High mobility transparent thin-film transistors with amorphous zinc tin oxide channel layer

Abstract

Transparent thin-film transistors (TTFTs) with an amorphous zinc tin oxide channel layer formed via rf magnetron sputter deposition are demonstrated. Field-effect mobilities of 5-15 and 20-50 cm(2) V-1 s(-1) are obtained for devices post-deposition annealed at 300 and 600 degreesC, respectively. TTFTs processed at 300 and 600 degreesC yield devices with turn-on voltage of 0-15 and -5-5 V, respectively. Under both processing conditions, a drain current on-to-off ratio greater than 10(7) is obtained. Zinc tin oxide is one example of a new class of high performance TTFT channel materials involving amorphous oxides composed of heavy-metal cations with (n-1)d(10) ns(0) (ngreater than or equal to4) electronic configurations. (C) 2005 American Institute of Physics.