Simulation Modeling of Ferroelectric‐Gated <scp>InSe 2D</scp> ‐ <scp>HEMT</scp> With Enhanced Electrostatic Control and <scp>2DEG</scp> Engineering Towards Biosensor Applications

ABSTRACT We present a ferroelectric‐gated 2D material‐based high electron mobility transistor (HEMT) that provides an innovative solution for the challenges associated with the electrostatic control‚ the carrier density and the power performance of the conventional 2D FETs and III‐V HEMTs. The device employs an atomically thin monolayer InSe channel and a ferroelectric HfO 2 high‐k gate stack that exploits the negative capacitance effect of ferroelectrics to achieve strong charge control and voltage gain for the 2D channel. Unlike the polarizations in conventional polarization‐induced HEMTs‚ the polarization created by the ferroelectric leads to the formation of a high carrier density 2DEG in an atomically thin channel. The electrostatics‚ transport‚ and RF performance of the device are modeled using detailed TCAD simulations. The simulated device has a positive threshold voltage (~0.35 V)‚ allowing it to operate in the normally‐OFF regime. The simulated 2DEG has a charge density of ~9 × 10 12 cm −2 and an electron mobility of ~1000 cm 2 /V‐s. We show peak transconductance values of ~500 mS/mm‚ low OFF‐state leakage current densities below 10 −12 A‚ improved subthreshold behaviors approaching sub‐thermionic switching‚ and excellent scalability‚ suppression of short‐channel effects‚ and good electrostatic gate control through the combined effect of the ferroelectric polarization and the 2D confinement mechanisms. Thus‚ the proposed ferroelectric‐assisted 2D HEMT overcomes the issue of conventional 2D FET and III‐V HEMT both the carrier density and gate control are improved simultaneously with low‐power consumption. This makes the ferroelectric‐assisted 2D HEMT a good candidate for next‐generation Nanoelectronic‚ RF and biosensing applications.