| 摘要 |
PROBLEM TO BE SOLVED: To provide a field-effect transistor having an epitaxial structure which enables achievement of the balance among good quality of crystalline, a high electron concentration and a high mobility. ! SOLUTION: A field-effect transistor comprises: a compound semiconductor epitaxial multilayer film. The compound semiconductor epitaxial multilayer film is produced by stacking, on a semi-insulative InP substrate 1, a buffer layer 2 of InAlAs, a first electron-supply layer 3, a first spacer layer 4 of InAlAs, a channel layer of InGaAs or InAs, a second spacer layer 8 of InAlAs, a second electron-supply layer 9, and a barrier layer 10 of InAlAs in turn. The field-effect transistor further comprises a gate electrode 14, a source electrode 15 and a drain electrode 16 which are formed above a Schottky junction forming layer. The first electron-supply layer 3 and the second electron-supply layer 9 each have a composition and a thickness which can prevent a lattice relaxation to be caused on the se |
