Field-effect transistor, semiconductor wafer, method for producing field-effect transistor and method for producing semiconductor wafer

Abstract

Provided is a field-effect transistor including a gate insulating layer, a first semiconductor crystal layer in contact with the gate insulating layer, and a second semiconductor crystal layer lattice-matching or pseudo lattice-matching the first semiconductor crystal layer. Here, the gate insulating layer, the first semiconductor crystal layer, and the second semiconductor crystal layer are arranged in the order of the gate insulating layer, the first semiconductor crystal layer, and the second semiconductor crystal layer, the first semiconductor crystal layer is made of InGaAsP(0<x1≦1, 0≦y1≦1), the second semiconductor crystal layer is made of InGaAsP(0≦x2≦1, 0≦y2≦1, y2≠y1), and the electron affinity Eof the first semiconductor crystal layer is lower than the electron affinity Eof the second semiconductor crystal layer.