Ferroelectricity in HfO₂ enables nonvolatile data storage in 28 nm HKMG

Abstract

We report on the most aggressively scaled ferroelectric field effect transistor so far. These were successfully fabricated using ferroelectric Si:HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in a 28 nm HKMG stack (TiN/Si:HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Si). For a ± 5 V program/erase operation with pulses as short as 20 ns, reliable threshold voltage shifts were observed resulting in a memory window of about 0.9 V. We further demonstrate endurance characteristics matching demands of current nonvolatile memories utilizing wear leveling. Low retention loss was observed and extrapolated 10-year data storage can be expected.