COMPOUND SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

PURPOSE:To provide the title compound semiconductor device and manufacturing method thereof composed of a gate metal contributing to the stabilization of the interfacial characteristics. CONSTITUTION:The title compound semiconductor device is composed of Ti (titanium) selected as a Schottky metal, furthermore, a gate metal layer of Al/barrier metal/Al formed as an upper layer metallic layer as well as a multilayer metal comprising (a GaAs substrate 1 containing an infinitesimal Ti)/a GaAlAs layer 5/a Ti layer 6/an Al layer 7/a barrier metallic layer 8/an Al layer 9 from the GaAs substrate l side as the gate part after the heat treatment step. In such a constitution, any freed gas from PR is adsorbed at the Ti layer, resultantly, enabling the pollution on the Schottky interface by this freed gas to be avoided; the surface to be stabilized by forming the GaAlAs layer 5 on the Schottky surface; the formation of the GaAlAs layer 5 to be moderately restrained by the barrier metal layer as an intermediate layer.