Total Ionizing Dose Effect in Tri-gate Silicon Ferroelectric Transistor Memory

Abstract

For the first time, we demonstrate the survivability of programmed states in a ferroelectric field effect transistor (FeFET) memory under gamma-ray irradiation. The un-irradiated Tri-gate Si FeFET (control) shows a large memory window (MW) of ~1.6V, a high read current window of ~2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> , a long retention of $2.3 \times 10 ^{6} \mathrm{s}$ (~27 days) and high endurance (>10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> cycles). The Tri-gate FeFETs, when exposed to radiation, retain ferroelectric hysteresis with a current window >10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> up to a high radiation dose of 10Mrad. This confirms the survivability of the FeFETs and makes FeFET a potential candidate for data storage and compute-in-memory (CIM) in harsh ionizing environment. Analysis of array-level performance of FeFET-based CIM accelerator trained on CIFAR-10 dataset using VGG-8 neural network model under 5Mrad and 10Mrad radiation shows inference accuracy of 90% and 80%, respectively, versus 92% for control.