Compound semiconductor device on silicon substrate and method of manufacturing the same

摘要

E and D mode HEMTs are integrated in a laminated layer of pairs of GaAs/AlGaAs layers formed on the same GaAs-on-Si substrate. The gate electrodes of E and D mode HEMTs are formed on different GaAs layers. The GaAs layer on Si contains crystal defects. It is hypothesized that the defects extend upward in the laminated layer of pairs of GaAs/AlGaAs layers formed on the GaAs layer with such crystal defects. Etch pits are generated as the AlGaAs layer is etched by ammonium etchant. Generation of etch pits can be suppressed by etching the whole part of the exposed AlGaAs layer and exposing the GaAs layer under the gate electrode.