Proposed vertical-type amorphous-silicon field-effect transistors

Abstract

Novel amorphous-silicon field-effect transistors (a-Si FET's) with a vertical channel have been proposed and demonstrated for the first time. The channel length of the new FET's is not limited by the photoetching process and thus can be reduced a great deal. Prototype FET's with a channel length of 1 µm had an on-off current ratio of more than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> and the on-resistance was proportional to the channel length, so far as it was longer than 1 µm.