A submicron split-gate AlGaN/GaN heterostructure field-effect transistor for class-A common-source voltage amplifier applications

Abstract

In this study, a submicron AlGaN/GaN heterostructure field-effect transistor with a split-gate structure was fabricated. Through measurements, it was found that the drain-source current of the submicron split-gate device was relatively small, and could be effectively modulated over a large gate voltage range. Corresponding theoretical analysis showed that the effective width of the conduction channel was larger than that of the gate opening after the electrons underneath the gate was depleted. When analyzing the transport characteristics of split-gate devices with small gate length and large gate-source and gate-drain distance, in addition to the influence of polarization Coulomb field scattering and gate fringe electric field, the difference of effective width between the conduction region and the gate opening should not be ignored. When used as a class-A common-source voltage amplifier, the submicron split-gate device can effectively amplify a larger input signal with high linearity and low power consumption.