50x Endurance Improvement in TaOx RRAM by Extrinsic Doping
Tim Kempen, Rainer Waser, Vikas Rana
Abstract
Resistive RAMs (RRAM) have shown immense promise in serving as the building blocks of in-memory computing systems for neuromorphic applications. However, high forming voltage, low endurance and poor retention below the 20nm technology node hinder its use. In this paper, we present a CMOS-compatible technique, which not only improves the endurance and retention but also lowers down the forming voltage of the RRAM device. The endurance and retention properties of TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> RRAM devices are augmented by implanting Zr atoms into the switching layer. The implanted devices (~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> cycles) on average show >50x higher endurance, than its counterparts (~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> cycles), while exhibiting the better retention properties. In addition, the forming voltage of the implanted devices is significantly reduced in comparison with non-implanted samples due to lowering of oxygen vacancy (Vo) formation energy.