Proposed vertical-type amorphous-silicon field-effect transistors

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 10⁴and the on-resistance was proportional to the channel length, so far as it was longer than 1 µm.