16kbit 1T1R OxRAM arrays embedded in 28nm FDSOI technology demonstrating low BER, high endurance, and compatibility with core logic transistors

Abstract

We present for the first time Si-doped HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based OxRAM 16kbit arrays integrated in the BEOL of 28nm FDSOI CMOS, targeting low cost and low power embedded applications. Excellent LRS/HRS raw distributions are reported on 1T-1R 16kbit arrays with zero bit-fail up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> cycles, using core logic (GO1) selector transistors. The OxRAM compatibility with GO1 transistors paves the way to arrays with minimum bitcell area of 0.066 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 125μA programming current. We also demonstrate direct correlation between transistor compliance current variability within the 1T-1R array and the LRS distribution. This result indicates that the intrinsic LRS variability is smaller than the measured one. SPICE Monte-Carlo simulations confirm the large compliance current dispersion measured on transistors designed at minimum gate length and show path to improve even further the LRS distribution and hence the OxRAM memory window.