FIELD EFFECT TRANSISTOR

摘要

PURPOSE: A field effect transistor is to make the linearity of mutual conductances gm flattened throughout the wider region of a gate bias. CONSTITUTION: A field effect transistor is a MESFET(metal semiconductor field effect transistor) comprising a cap layer(17) having Schottky conjunction with a channel layer(13) and a gate electrode(20), and especially, one or more subsidiary layers are formed between the channel layer and the cap layer, a doping concentration of the one or more subsidiary layers being lower than that of the channel layer and higher than that of the cap layer. The profile of the doping concentration of the one or more subsidiary layers is set to decrease from the channel layer to the cap layer in the exponential functional form.