Nonvolatile Electrochemical Memory at 600C Enabled by Composition Phase Separation

TL;DR

This paper introduces a novel nonvolatile electrochemical memory capable of operating and retaining information at temperatures up to 600°C, leveraging phase separation in amorphous tantalum oxide.

Contribution

It demonstrates a high-temperature nonvolatile memory device based on composition phase separation, enabling operation beyond traditional CMOS temperature limits.

Findings

Memory retains data at 600°C

Phase separation between oxidized and reduced tantalum oxide is key

Correlative electron microscopy confirms the mechanism

Abstract

CMOS-based microelectronics are limited to ~150{\deg}C and therefore not suitable for the extreme high temperatures in aerospace, energy, and space applications. While wide bandgap semiconductors can provide high-temperature logic, nonvolatile memory devices at high temperatures have been challenging. In this work, we develop a nonvolatile electrochemical memory cell that stores and retains analog and digital information at temperatures as high as 600 {\deg}C. Through correlative electron microscopy, we show that this high-temperature information retention is a result of composition phase separation between the oxidized and reduced forms of amorphous tantalum oxide. This result demonstrates a memory concept that is resilient at extreme temperatures and reveals phase separation as the principal mechanism that enables nonvolatile information storage in these electrochemical memory cells.