LK-Model-Based TCAD Simulation of Hafnium-Oxide-Based Ferroelectric Memcapacitors for Radiation-Tolerant Neuromorphic Capacitive Synapses

Abstract A W/HZO/HfO2/W/Si ferroelectric memcapacitor was simulated in Silvaco TCAD using the Landau-Khalatnikov (LK) ferroelectric model to examine multilevel capacitance modulation, total ionizing dose (TID) effects, and device-to-system neuromorphic behavior. The simulations show that increasing the write-voltage amplitude strengthens polarization modulation in the HZO layer, producing wider P-V hysteresis loops, clearer switching-current responses, and improved capacitance-state separation. The capacitive memory window (CMW), defined as the zero-bias capacitance-density difference between the upper and lower C-V branches, increases with write voltage, indicating enhanced multilevel capacitance tunability. Under TID irradiation, oxide charge trapping and the associated electric-field perturbation reduce the C-V branch separation and CMW in the adopted model, while distinguishable capacitance states are retained within the investigated dose range. The TCAD-extracted capacitance states were further mapped to synaptic weights for multilayer perceptron (MLP)-based MNIST evaluation. Although irradiation compresses the available capacitance range, the normalized weight states remain sufficiently ordered for stable classification in this simulation framework. These results provide a device-to-system TCAD workflow for evaluating hafnium-based ferroelectric memcapacitors as candidate radiation-tolerant capacitive synapses.