Logic Compatible High-Performance Ferroelectric Transistor Memory
Sourav Dutta, Huacheng Ye, Akif A. Khandker, Sharadindu Gopal Kirtania, Abhishek Khanna, Kai Ni, Suman Datta
Abstract
Silicon channel ferroelectric field-effect transistors (FeFETs) with low-k interfacial layer (IL) between ferroelectric and silicon channel suffers from high write voltage, limited write endurance and long read-after-write latency. This is due to early IL breakdown and mobile charge injection at the ferroelectric-IL interface. Here, we demonstrate low voltage, high speed memory operation with high write endurance using an IL-free back-end-of-line (BEOL) compatible FeFET. We fabricated IL-free FeFETs with 28nm channel length (Lg) and 126nm width under a thermal budget < 400<sup>0</sup> C by integrating 5nm Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> (HZO) gate stack with amorphous Indium Tungsten Oxide (IWO) semiconductor channel. We report a voltage memory window of 1.6V with a read current window <inline-formula> <tex-math notation="LaTeX">${I}_{\textit {LVT}}{/}{I}_{\textit {HVT}}$ </tex-math></inline-formula> of 10<sup>5</sup>, write voltage of ±1.6V with 20ns pulses, instantaneous read-after-write latency < 300ns and a record high write endurance exceeding 10<sup>11</sup> cycles. This establishes the IL-free BEOL FeFET as a promising candidate for logic-compatible high-performance last-level cache memory.