A forming-free WO<inf>x</inf> resistive memory using a novel self-aligned field enhancement feature with excellent reliability and scalability

Abstract

A thorough study of the switching mechanism for WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> ReRAM gives clues about how to improve its performance and reliability. Consequently, a 60 nm WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> ReRAM is achieved with excellent characteristics - 50ns fast switching, 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> cycling endurance, large MLC window, low read disturb of >; 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> , and excellent 150°C/2,000Hrs data retention. Furthermore, the oxidation of the TiN barrier into an insulating TiNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> causes the WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> to protrude above the remaining TiN and thus creates field enhancement. The boosted electric field eliminates the need for an initial forming step.