Oxygen migration during resistance switching and failure of hafnium oxide memristors

TL;DR

This study investigates oxygen migration in hafnium oxide memristors during switching and failure, revealing physical causes of failure and engineering solutions that significantly improve device endurance.

Contribution

It provides direct in-situ observation of oxygen migration during device aging and failure, leading to design improvements that enhance memristor endurance.

Findings

Lateral oxygen migration observed during switching and failure

Identified physical causes of memristor failure

Achieved three orders of magnitude improvement in endurance

Abstract

While the recent establishment of the role of thermophoresis/diffusion-driven oxygen migration during resistance switching in metal oxide memristors provided critical insights required for memristor modeling, extended investigations of the role of oxygen migration during ageing and failure remain to be detailed. Such detailing will enable failure-tolerant design, which can lead to enhanced performance of memristor-based next-generation storage-class memory. Here we directly observed lateral oxygen migration using in-situ synchrotron x-ray absorption spectromicroscopy of HfOx memristors during initial resistance switching, wear over millions of switching cycles, and eventual failure, through which we determined potential physical causes of failure. Using this information, we reengineered devices to mitigate three failure mechanisms, and demonstrated an improvement in endurance of about three orders of magnitude.