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

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 $20–50{\mathrm{cm}}^2{\mathrm{V}}^{-1}{\mathrm{s}}^{-1}$ are obtained for devices post-deposition annealed at 300 and $600°\mathrm{C}$ , respectively. TTFTs processed at 300 and $600°\mathrm{C}$ yield devices with turn-on voltage of 0–15 and $-5–5\mathrm{V}$ , 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 $(n-1)d^{10}{\mathrm{ns}}^0$ $(n⩾4)$ electronic configurations.