Ga/sub 0.47/In/sub 0.53/As-InP HEMTs with novel GaP/sub 0.35/Sb/sub 0.65/ Schottky layers grown by MOVPE

In this paper, we report on the first HEMT fabricated using a novel GaP/sub 0.35/Sb/sub 0.65/ Schottky layer. The AlGaPSb materials system provides the potential for a new class of HEMT devices with a performance that exceeds the Al/sub 0.48/In/sub 0.52/As-Ga/sub 0.47/In/sub 0.53/As materials system. One of the advantages of the PSb materials system (AlGaPSb) is that it can be grown lattice-matched to both InP and GaAs substrates. The bandgap of AlPSb lattice-matched to InP substrate is approximately 1.93 eV, while when lattice matched to GaAs substrates, the bandgap of AlPSb is 2.3 eV. In addition, the GaP/sub 0.35/Sb/sub 0.65/-Ga/sub 0.47/In/sub 0.53/As materials system has a conduction band discontinuity of -0.6 eV and for the AlP/sub 0.39/Sb/sub 0.61/-Ga/sub 0.47/In/sub 0.53/As materials system, the conduction discontinuity is approximately 1.06 eV. The wide bandgap combined with the large conduction band discontinuity for the AlGaPSb materials system should lead to development of high-performance millimeter wave low-noise and power HEMTs. We have demonstrated a GaP/sub 0.35/Sb/sub 0.65/-Ga/sub 0.47/In/sub 0.53/As HEMT on InP substrate as a first step toward the demonstration of an AlP/sub 0.39/Sb/sub 0.61/-Ga/sub 0.47/In/sub 0.53/As HEMT.