Random soft error suppression by stoichiometric engineering: CMOS compatible and reliable 1Mb HfO2-ReRAM with 2 extra masks for embedded IoT systems

12" manufacturable 90nm CMOS fully compatible 1Mb HfO
₂
-ReRAM by 2 extra masks between Metals with BEoL thermal stress immunity is for the first time achieved in this work. Cycle random soft error, for the first time systematically observed in this work, due to improper phase-transition of TiO
_δ
on filament are successfully suppressed by stoichiometric engineering on HfO
₂
/ reservoir interface to achieve reliable 20K / 100K endurance and 85°C 10 years retention. This technology can thus offer potential applications of embedded IoT systems due to low energy consumption and cost effective benefit.