Patent ID: 8415713

Claim:
A photo-FET wherein an FET part is stacked on a photodiode part, said photo-FET comprising at least: a semiconductor layer forming a photo-absorption layer of said photodiode part, which is formed on a cathode semiconductor layer of said photodiode part; an electron barrier layer, which is formed on said photo-absorption layer and forms a semiconductor layer with a bandgap wider than that of said photo-absorption layer, and works as an anode layer of said photodiode; a channel layer, which is formed on said electron barrier layer and forms a semiconductor layer with a bandgap narrower than that of said electron barrier layer, said channel layer forming a channel region of said FET part; a hole barrier layer, which is formed on said channel layer and comprises a semiconductor with a bandgap wider than that of said channel layer; and a source electrode and a drain electrode, formed on said hole barrier layer, which are separated from each other; wherein holes injected into said channel layer, by light illumination, through said electron barrier layer from said photo-absorption layer are confined in the channel layer by said hole barrier layer, and electrons in the channel layer are also confined in this channel layer by said electron barrier layer.