Highly-scalable novel access device based on Mixed Ionic Electronic conduction (MIEC) materials for high density phase change memory (PCM) arrays

Phase change memory (PCM) could potentially achieve high density with large, 3Dstacked crosspoint arrays, but not without a BEOL-friendly access device (AD) that can provide high current densities and large ON/OFF ratios. We demonstrate a novel AD based on Cu-ion motion in novel Cu-containing Mixed Ionic Electronic Conduction (MIEC) materials[1, 2]. Experimental results on various device structures show that these ADs provide the ultra-high current densities needed for PCM, exhibit high ON/OFF ratios with excellent uniformity, are highly scalable, and are compatible with <;400°C Back-End-Of-the-Line (BEOL) fabrication.