High-Performance Operation and Solder Reflow Compatibility in BEOL-Integrated 16-kb HfO<sub>2</sub>: Si-Based 1T-1C FeRAM Arrays
T. François, J. Coignus, Adam Makosiej, Bastien Giraud, C. Carabasse, Justine Barbot, Sébastien Martin, N. Castellani, T. Magis, H. Grampeix, S. Van Duijn, C. Mounet, P. Chiquet, Uwe Schroeder, Stefan Slesazeck, Thomas Mikolajick, E. Nowak, M. Bocquet, N. Barrett, F. Andrieu, L. Grenouillet
Abstract
16-kb 1T-1C ferroelectric random access memory (FeRAM) arrays are demonstrated for 130-nm node technology with TiN/HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> :Si/TiN ferroelectric capacitors integrated into the back-end-of-line (BEOL). The 0- and 1-state distributions measured on the arrays demonstrate perfect yield at 4.8-V operation, with extrapolations suggesting that the memory window (MW) is still open at six-sigma statistics. A programming speed down to 4 ns at 4 V is highlighted at the array level, together with an endurance up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{7}}$ </tex-math></inline-formula> cycles. Promising data retention up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{4}}$ </tex-math></inline-formula> s at 125 °C is measured on the arrays and, for the first time, solder reflow compatibility is demonstrated for HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based FeRAM. The MW on 16-kb arrays remains open when using a 2.5-V programming voltage and when the capacitor area is decreased from 0.36 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}^{{2}}$ </tex-math></inline-formula> down to 0.16 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}^{{2}}$ </tex-math></inline-formula> , with a calculated programming energy lower than 100 fJ/bit. These results pave the way to competitive ultralow-power embedded nonvolatile memories (NVM) at more advanced nodes.