Parametrical Study on the Preparation of an InAs/AlSb 2DEG Structure for Application to a High-mobility Inverted-doping HEMT

Abstract

We have investigated the change in the electron mobility of InAs/AlSb two-dimensional electron gas (2DEC) structures under various growth conditions. The optimum transport characteristics of the InAs/AlSb 2DEG are achieved when the InAs channel is grown to a proper thickness under a suitable arsenic flux with a modified shutter sequence and with an extra GaSb layer overlaid on the tipper AlSb layer of the channel. The resulting inverted-doping high-electron-mobility-transistor (HEMT) structure including an n-doped InAs layer under the InAs channel, is found to have a mobility as high as similar to 28,270 cm(2)/Vs at 300 K and similar to 160,300 cm(2)/Vs at 77 K. This value of mobility at 300 K is three times larger than that of previously reported for a InAs/AlSb inverted-doping HEMT and is comparable with conventional counterparts. Furthermore, this high-mobility InAs/AlSb inverted-doping HEMT is newly realized.