Optimization of InxGa1-xP/In0.2Ga0.8As/GaAs high electron mobility transistor structures grown by solid source molecular beam epitaxy

A strained In0.40Ga0.60P/In0.2Ga0.8As/GaAs pseudomorphic high electron mobi lity 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 struc ture, indicating that better electron distribution was formed in such a str ucture. Photoluminescence (PL) measurements verified that the incorporation of a strained barrier and a smoothing layer into the PHEMT structure modif ies the electron distribution so that most of the electrons were distribute d in the In0.2Ga0.8As channel, resulting in high electron mobility. Better device performances were also obtained in the proposed strained InxGa1-xP/ In0.2Ga0.8As/GaAs PHEMT structures. These results demonstrated that straine d InxGa1-xP/In0.2Ga0.8As PHEMTs are superior to the lattice-matched ones, a nd they are very promising candidates for microwave power applications. (C) 2000 Elsevier Science S.A. All rights reserved.