In this paper, a dielectric modulated negative capacitance (NC)-MoS2 field effect transistor (FET)-based biosensor is proposed for label-free detection of biomolecules such as enzymes, proteins, DNA, etc. Various reports present experimental demonstration and modelling of NC-MoS2 FET, but it is never utilized as a dielectric modulated biosensor. Therefore, in this work, the modelling, characterization and sensitivity analysis of dielectric modulated NC-MoS2 FET is focussed. For immobilization of biomolecules, a nanocavity is formed below the gate by etching some portion of the gate oxide material. The immobilization of biomolecules in the cavity leads to a variation of different electrostatic properties such as surface potential, threshold voltage, drain current, and subthreshold-swing (SS) which can be utilized as sensing parameters. An analytical model for the proposed biosensor is also developed in the subthreshold region by considering the properties of two-dimensional (2D) ferroelectric materials and benchmarked with TCAD device simulations. The effect of change of gate length and doping concentration on different electrical properties is also analysed to estimate the optimum value of channel doping. The results prove that the proposed device can be used for next-generation low power label-free biosensor which shows enhanced sensitivity as compared to traditional FET-based biosensors.

In this paper, we report record DC and RF performance in β-Ga2O3 High Electron Mobility Transistor (HEMT) with field-plate T-gate using 2-D simulations. The T gate with head-length LHL of 180 nm and foot-length LFL of 120 nm is used in the highly scaled device with an aspect ratio (LG/tbarrier) of ~ 5. The proposed device takes advantage of a highly polarized Aluminum Nitride (AlN) barrier layer to achieve high Two-Dimensional Electron Gas (2DEG) density in the order of 2.3 × 1013 cm-2, due to spontaneous as well as piezoelectric polarization components. In the depletion mode operation, maximum drain current ID,MAX of 1.32 A/mm, and relatively flat transconductance characteristics with a maximum value of 0.32 S/mm are measured. The device with source-drain distance LSD of 1.9 µm exhibits record low specific-on resistance RON,sp of 0.136 mΩ-cm–2, and off-state breakdown voltage of 403 V, which correspond to the record power figure-of-merit (PFoM) of ~ 1194 MW/cm2. Additionally, current gain cut-off frequency fT and maximum oscillation frequency fMAX of 48 and 142 GHz are estimated. The obtained results show the potential of Ga2O3 HEMT for futuristic power devices.

Here we demonstrate a two-dimensional β-gallium oxide-based high electron mobility transistor (HEMT) comprising of a finite gap—access region gap (L_ARG ) in Ohmic-contact access regions with record transconductance linearity. Apart from limiting two-dimensional electron gas (2DEG) density n_s dependency on gate voltage, higher saturation current is estimated for the proposed design. Since the access regions length directly affects the Capacitance of the device and resultant switching applications. In this work, the effect of the gate-source and gate-drain length on device linearity is performed using Atlas-2D simulations. C-V characteristics of the proposed device are explained based on the physical explanation and validated using appropriate models. The higher values of transconductance g_m and current gain cut-off frequency f_T on a large span of operating voltages ensure improved transistor performance for low-noise amplification and RF application and are reported for the first time.