Investigation of InGaAs based pseudomorphic step-doped-channel field-effect transistor (SDCFET)

A heterostructure field-effect transistor (HFET) with a pseudomorphic step-doped-channel (SDC) profile has been fabricated and investigated. The studied SDCFET provides the advantages of high current density, high breakdown voltage, large gate voltage swing for high transconductance operation, and the adjustable threshold voltage. In this paper, a theoretical model is built to analyze the DC performance. For a practical device of 1 x 100 mu m(2) gated dimension, a maximum drain saturation current of 735 mAmm(-1), a maximum transconductance of 200 mSmm(-1), a gate breakdown voltage of 15 V, a wide gate voltage swing of 3.3 V with transconductance (g(m)) higher than 150 mSmm(-1) and a threshold voltage of -3.7 V are obtained, respectively. The theoretical data are consistent with experimental results. These good performances show the studied SDCFET have promise for high-speed, high-power circuit applications. (C) 1997 Elsevier Science Ltd.