Submicron double heterojunction strained InAlAs/InGaAs HEMTs: an experimental study of DC and microwave properties

Abstract

The DC and microwave characteristics of strained double-heterojunction InAlAs/InGaAs HEMTs with submicron gate lengths are presented. Low output conductance, (16-18 mS/mm) is retained even at short (0.25- mu m) gate length. Extrinsic f/sub T/ and f/sub max/ for these devices are as high as 82 GHz and 148 GHz, respectively. These results show the possibility of using the double-heterojunction approach and the associated improved carrier confinement in order to enhance the power gain performance. Microwave characterization of devices with different gate lengths revealed an effective carrier velocity of approximately 1.2*10/sup 7/ cm/s, indicating that carrier transport may be limited by the quality of the inverted heterointerface. Growth interruption optimization may further improve the performance of these devices.<>