Operation and stability analysis of bipolar OxRRAM-based Non-Volatile 8T2R SRAM as solution for information back-up

This work presents a Non-Volatile SRAM (NV-SRAM) cell, resilient to information loss. The cell features fast storage (20 ns) for the operating voltage of 1.0 V. The information is backed-up during POWER-DOWN/RESTORE cycle in two bipolar Oxide Resistive RAMs (OxRRAMs). The proposed NV-SRAM is designed with an 8T2R structure using 22 nm FDSOI technology and resistive memory devices based on HfO2. The stability and the reliability of the NV-SRAM cell is investigated by taking into account the variability of the transistors. It is shown that high ROFF/RON is necessary to ensure reliable RESTORE operation and high SRAM yield under cell area and power consumption constraints.

► We designed an NVSRAM cell with 22 nm FDSOI PDK for CMOS and HfO2 OxRRAMs. ► We showed that our NVSRAM cell is operational at high speed (20ns) and low voltage (1.5V). ► We presented the first analysis of VT variability on the stability of an 8T2R NV-SRAM. ► We showed that ROFF/RON of 10 is necessary to have sufficient reliability of RESTORE.