Photo-field effect transistor and its production method

Abstract

This invention provides a photo-FET, in which a FET part and photodiode part are stacked, and the FET part and photodiode part are optimized independently in design and operational bias conditions. The semiconductor layer serving as a photo-absorption layer () is formed on the cathode semiconductor layer () of a photodiode part (). An electron barrier layer () with a wider bandgap semiconductor than a photo-absorption layer (), which also serves as an anode layer of a photodiode part (), is formed on a photo-absorption layer (). The channel layer () which constitutes the channel regions of the FET part is formed with a narrower bandgap semiconductor than an electron barrier layer () on an electron barrier layer (). The hole barrier layer () with a bandgap wider than the semiconductor which constitutes a channel layer () is formed on a channel layer (). The source electrode () and drain electrode () which are separated each others, are formed on a hole barrier layer (). The holes injected into the channel layer () by light illumination through the electron barrier layer () from the photo-absorption layer () are confined with the hole barrier layer (). And the electrons in a channel layer () are confined with the electron barrier layer () into the channel layer (), respectively.