Field effect transistor having a spacer layer with different material and different high frequency characteristics than an electrode supply layer thereon

摘要

There is disclosed a field effect transistor having a channel layer, an electron supply layer, and a spacer layer formed between the channel layer and the electron supply layer. The spacer layer has a thickness for spatially separating a two-dimensional electron gas from donor ions in the electron supply layer, and for forming the two- dimensional electron gas in the channel layer by the Coulomb force of the donor ions. The spacer layer material has better high frequency characteristics than that of the electron supply layer.