A Comparative Study on Inverters Built With Dual-Gate Thin-Film Transistors Based on Depletion- or Enhancement-Mode Technologies

In the absence of a mature p-type thin-film transistor (TFT) technology, a unipolar n-type TFT technology offering two flavors of TFTs with different threshold voltage (
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) values is more versatile than one offering only one flavor with a fixed
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. Hitherto, a consensus has yet to be achieved on a preferred multi-
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TFT technology based on metal–oxide–semiconductors. With its channel region sandwiched between two separate gate electrodes, a dual-gate (DG) TFT is one viable and flexible approach of operating a TFT in either the enhancement or the depletion mode. Two multi-
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DG TFT technologies are possible, based on those offering intrinsically depletion or enhancement mode single-gate TFTs. A comparative study has been conducted, and it is concluded that the former generally offers circuits with better performance attributes.