Highly reliable TaO<inf>x</inf> ReRAM with centralized filament for 28-nm embedded application

Abstract

For 28-nm embedded application, we have proposed a TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> -based ReRAM with precise filament positioning and high thermal stability. The cell was realized using several newly-developed process technologies and cell structures: low-damage etching, cell side oxidation and encapsulated cell structure. As a result, we succeeded for the first time in forming a filament at the cell center. In addition, we confirmed the feasibility of 20-nm cell size. Excellent reliability was achieved in 2-Mbit 40-nm ReRAM: 100k cycles and 10 years' retention at 85°C was demonstrated.