MESFETs and inverters based on amorphous zinc-tin-oxide thin films prepared at room temperature

Room temperature fabrication of amorphous oxide semiconductors enables a cost-efficient production of devices on flexible and large-area substrates. Metal-semiconductor field-effect transistors using amorphous zinc-tin-oxide (ZTO) thin films with a cation composition of 1:1 Zn:Sn are presented. The n-type ZTO channel is deposited by long-throw magnetron sputtering from a ceramic target at room temperature on glass substrates. Reactively sputtered platinum is used as a gate contact material. We report on/off current ratios as high as 1.8 x 10(6), a threshold voltage of 0.47 V, and a sub-threshold swing of 124 mV dec(-1) for as-fabricated devices. Using negative bias treatment, an improvement in device properties is observed, namely, a decrease in the off-current by two orders of magnitude and a reduction of the sub-threshold swing. An inverter based on as-deposited ZTO metal-semiconductor field-effect transistors exhibits a high peak gain magnitude of 119 and a small uncertainty level of 160 mV for a supply voltage of 3 V. Published by AIP Publishing.