Threshold voltage extraction techniques adaptable from sub-micron CMOS to large-area oxide TFT technologies

This paper proposed simple and accurate threshold voltage (V_TH) extraction techniques, which can be directly adaptable to various semiconductor technologies ranging from deep sub-micron complementary metal-oxide-semiconductor to large-area thin-film transistor devices. These techniques are developed using multiple circuits, namely, a dynamic source follower, an inverter with a diode-connected load and a current mirror topology, which allow a direct determination of V_TH. As the proposed techniques are experimented with large-area emerging technologies, which have a stable single type (n-type) transistor, all the designs employed in this work are confined to only n-type transistors for a fair comparison. The semiconductor technologies under consideration are standard complementary metal-oxide-semiconductor (65 and 130 nm) and oxide (indium-gallium-zinc-oxide and zinc-tin-oxide) thin-film transistors. In order to validate the accuracy of the proposed techniques, extracted V_TH from these methods are compared against the value from linear transfer characteristics. The resulting relative error is within 5%, reinforcing proposed techniques suitability to different semiconductor technologies ranging from deep sub-micron to large-area transistors.