Analytical Modeling of MgZnO/ZnO MOSHEMT Based Biosensor for Biomolecule Detection

Abstract

In recent development, the High Electron Mobility Transistor (HEMT) technology was used for biosensor applications. In this contribution, an analytical model of MgZnO/ZnO MOSHEMT (Metal Oxide Semiconductor HEMT) was reported. For the first time, a nanogap cavity-based biosensor aimed at detecting various biomolecules, such as uricase, streptavidin, ChOx, and proteins, was designed. The developed analytical model was used to calculate the two-dimensional electron gas (2DEG) density, device capacitance, drain current (ID), output conductance (gd), and transconductance (gm) by using the dielectric modulation approach. MOSHEMTs used dielectric modulation, with the nanogap cavity considered under the gate region. The effective capacitance in the cavity region was obtained by using dielectric modulation. Hence, the nanogap cavity acts as a sensing area for the immobilisation of target biomolecules. The sensitivity of the device was analysed by observing the strong changes in drain current with the addition of different biomolecules in the nanogap cavity region. The proposed MgZnO/ZnO MOSHEMT biosensor exhibits a quick response to biomolecule changes since its drain-on-sensitivity (SIon) is comparatively higher than that of other semiconductor-based biosensors. The obtained analytical model results were verified by a comparison with other works available in the literature, and they showed good agreement with our results.