Optimization of In xGa 1− xP/In 0.2Ga 0.8As/GaAs high electron mobility transistor structures grown by solid source molecular beam epitaxy

Abstract

A strained In 0.40Ga 0.60P/In 0.2Ga 0.8As/GaAs pseudomorphic high electron mobility transistor (PHEMT) structure was proposed to improve electron mobility. The structures were successfully grown by the solid source molecular beam epitaxy technique. Higher Hall mobility was achieved in the proposed structure, indicating that better electron distribution was formed in such a structure. Photoluminescence (PL) measurements verified that the incorporation of a strained barrier and a smoothing layer into the PHEMT structure modifies the electron distribution so that most of the electrons were distributed in the In 0.2Ga 0.8As channel, resulting in high electron mobility. Better device performances were also obtained in the proposed strained In x Ga 1− x P/In 0.2Ga 0.8As/GaAs PHEMT structures. These results demonstrated that strained In x Ga 1− x P/In 0.2Ga 0.8As PHEMTs are superior to the lattice-matched ones, and they are very promising candidates for microwave power applications.