Sensitivity improvement in gate engineered technique dielectric modulated GaN MOSHEMT with InGaN notch for label-free biosensing

Abstract

This paper focuses on the impact of gate-engineered dielectric-modulated GaN MOSHEMT with InGaN notch on sensitivity enhancement for label-free biosensing. The novelty of this study utilizes the charge-plasma effect induced by the dual metal gate (DMG) technology adopted to realize the effect of sensitivity on different biomolecules. Moreover, the presence of an InGaN notch enhances carrier confinement in the 2DEG, subsequently improving the threshold voltage and device sensitivity at the AlGaN/GaN interface. The maximum drain current, IDS of 4.602 A mm−1, transconductance, gm of 18 mS/mm, and sensitivity has been improved by around 61% for the Uricase biomolecule by introducing the dual metal gate technology. The work function difference of the two metal gates suppresses the Short Channel Effects (SCEs) and hot carrier effects in DMG MOSHEMT, thereby screening the drain potential variations by the gate near the drain. In addition, increased carrier transport efficiency results from a more consistent electric field along the channel. All the simulations are carried out using the Sentaurus TCAD simulator, and the results imply the feasibility of gate-engineered GaN MOSHEMT for label-free biosensing.