Semiconductor device and field effect transistor with controllable threshold voltage

摘要

A field effect transistor includes a substrate and a semiconductor layer provided on the substrate, wherein the semiconductor layer includes a lower barrier layer provided on the substrate, Ga-face grown, lattice relaxed, and having a composition In1−zAlzN (0≦z≦1), a channel layer having a composition of: AlxGa1−xN (0≦x≦1) or InyGa1−yN (0≦y≦1). Or GaN provided on and lattice-matched to the lower barrier layer, a source electrode and a drain electrode having ohmic contact to an upper part of the semiconductor layers, disposed spaced to each other, and a gate electrode arranged via a gate insulating film in a region lying between the source electrode and the drain electrode.

主权项

1. A semiconductor device including a field effect transistor comprising:
a substrate; a lower barrier layer provided on the substrate; a channel layer provided on the lower barrier layer; an electron supplying layer provided on the channel layer; a source electrode and a drain electrode provided on the electron supplying layer; and a gate electrode provided between the source electrode and the drain electrode, wherein the lower barrier layer includes a composition of In1−zAlzN(0≦z≦1), wherein the channel layer includes a composition of InyGa1−yN(0≦y≦1), wherein a recess is provided in a region between the source electrode and the drain electrode, wherein the recess goes through the electron supplying layer to a depth that exposes the channel layer, and wherein the gate electrode is disposed on a gate insulating film that covers a bottom surface and an inner wall surface of the recess.