Investigation of an InGaAsGaAs doped-channel MIS-like pseudomorphic transistor

Abstract

A GaAsInGaAs doped-channel MIS-like pseudomorphic FET has been fabricated and investigated. The device under study shows advantages of high breakdown voltage, high current capability, very large gate voltage swing for high transconductance operations, and ease of fabrication. For a 2 × 100 μm 2 gate device, a breakdown voltage of 17.4 V, a maximum drain saturation current of 930 mA/mm, a maximum transconductance of 230 mS/mm, and a very broad gate voltage range larger than 3 V with the transconductance higher than 200 mS/mm are obtained. An estimated electron saturation velocity v s up to 2.2 × 10 7 cm/s is acquired even for a thin InGaAs channel layer with a 4 × 10 18 cm −3 doping level. A simple two-layer model is also proposed to study the theoretical properties which shows a good agreement with the experimental results. Consequently, the device demonstrates a good potential for use in high-speed, high power and large input signal circuit applications.