20nm gate bulk-finFET SONOS flash

Abstract

High-performance FinFET SONOS (silicon-oxide-nitride-oxide-silicon) flash cells with gate length down to 20nm have been fabricated and operated successfully on bulk-silicon substrate for the first time. A program/erase window of 2V has been achieved with high P/E speed (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</sub> equiv 10mus and TE equiv 1ms), and a 1.5V window remained after 10 years at room temperature. Multi-level storage is also obtained with DeltaV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t </sub> > 4V and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P,E</sub> equiv 1 ms. Operation voltages are not more than 7V in the two applications. Gate disturb issues are alleviated by applying an appropriate bias on unselected bit lines