Design Points of InGaAs MFMIS Tunnel FET for Large Memory Window and Stable Ferroelectric Memory Operation

We study device structures and their design points of HfZrO_X -based InGaAs metal-ferroelectric-metal-insulator-semiconductor (MFMIS) ferroelectric tunnel FETs (Fe-TFETs) based on ferroelectric (FE) polarization-controlled band-to-band tunneling (BTBT) for stable nonvolatile memory (NVM) operation. We monolithically integrated a HfZrO_X MFM capacitor into the baseline tunnel field-effect transistor (TFET), which has steep subthreshold swing (SS) characteristics of sub-60 mV/decade with a HfO₂/Al₂O₃ gate-stack, compared to the reference MOSFET. We found temperature-stable NVM behaviors of the InGaAs Fe-TFET compared to the InGaAs ferroelectric MOSFETs (Fe-MOSFETs) at the measurement temperature range from -20 °C to 85 °C. Furthermore, we explored the scaling effects of the MFMIS structure using a high-{κ} HfO₂ gate insulator layer to pursue a steep SS, and a large capacitance ratio between the dielectric (DE) and FE capacitors. The InGaAs MFMIS-structure Fe-TFET achieves stable retention over 10⁴ s and excellent endurance during 10⁶ cycles at the DE/FE capacitance ratio of 27.5.