SoC compatible 1 T1 C FeRAM memory array based on ferroelectric Hf0.5Zr0.5O2

Abstract

This paper experimentally demonstrates fundamental memory array operation of a ferroelectric HfO2-based 1 T1 C FeRAM. Metal/ferroelectric/metal (MFM) capacitors consisting of a TiN/ $\mathrm{Hf}_{0.5}\mathrm{Zr}_{0.5}\mathrm{O}_{2}(\mathrm{HZO}$)/TiN stack were optimized for a sub 500°C process. Structures revealed excellent performance such as remanent polarization $2\mathrm{P}_{\mathrm{r}} > 4\vert \mu\mathrm{C}/\mathrm{cm}^{2}$, endurance> 1011 cycles, and 10 years data retention at 85°C. Furthermore, the MFM capacitors were successfully integrated into a 64 kbit 1T1C FeRAM array including our dedicated circuit for array operation. Back-end-of-line (BEOL) wiring showed no degradation of the underlying CMOS logic. Program and read operation were properly controlled resulting in 100 % bit functionality at an operation voltage of2.5 Vand operating speed at 14 ns. This technology matches requirements of last level cash (LLC) and embedded non-volatile-memory (NVM) in low power System-on-a-Chip (SoC) for IoT applications.