Patent ID: 8022440
Filing Date: 2011-09-20
Classification: H01L

Abstract:
1. A compound semiconductor epitaxial substrate having a pseudomorphic high electron mobility field effect transistor structure comprising: a starting substrate, an InGaAs layer as a strained channel layer, an InGaP layer containing n type impurities and not in an orderly state as a front side electron-donating layer, and an InGaP layer in an orderly state as a gate barrier layer, in this order, wherein the InGaP front side electron-donating layer is lattice matched to a GaAs layer disposed between the starting substrate and the InGaP front side electron-donating layer, the orderly state is a state where the band gap value for the InGaP layer is 1.85 eV or less, and the compositional ratios of the InGaP front side electron-donating layer and the InGaP gate barrier layer are the same.