Harnessing Maximum Negative Capacitance Signature Voltage Window in P(VDF-TrFE) Gate Stack

Abstract

In this paper, the observation of transient negative capacitance signature (NCS) in an organic ferroelectric gate stack (OFEGS) at minimum supply voltage (Vs) of ±0.5 V is investigated employing a well-calibrated Ginzburg-Landau-Khalatnikov (GLK) model in the environment of Sentaurus technology computer-aided design (STCAD). We observe an 88.62 to 94.76 % reduction in the average coercive voltage (Vc) of the proposed OFEGS, which is still a significant challenge for the conventional ferroelectric (FE) lead zirconate titanate. We study the resistor-OFEGS (RCofe) series network behaviors in response to a bipolar and unipolar triangular signal. Our findings prove that the presence of NCS is directly correlated with the FE polarization (FEP) switching and not because of any extrinsic defects in the system. The various impacts of Vs, GLK parameters, R, dipole switching resistivity (Rofe) variations on the NCS response are investigated. The proposed OFEGS can harness the NCS effect at ±0.5 V with minimum energy dissipation of 4.81 × 10-16 J, a challenge for the oxide FE-based gate stacks. Calibrating R to the maximum limit, we can capture the S-shaped ideal Landau path where the NCS is maximum with a small deviation of about ±0.006 V at zero FEP. Finally, an OFEGS based Landau transistor is implemented, providing a minimum subthreshold swing (SSmin) of 38.21 mV/decade, which is 36.32 % lesser than the fundamental SSmin limitation of 60 mV/decade. Therefore, the proposed OFEGS with a minimum Vs and remanent polarization (Pr =3D 1.244 μC/cm2) could be used as a gate stack for designing sub-60 mV/decade transistor technology.