In Situ Study of Resistive Switching in a Nitride-Based Memristive Device

Abstract

Resistive switching (RS) devices with ultra-low-voltage threshold and reliable switching repeatability exhibits great potential applications in energy-efficient data storage and neuromorphic computing. Understanding switching mechanisms at nanoscale is critical to design RS devices with improved performance. In this work, a lamella memristive device using focused ion beam (FIB) method based on the metal/TiOx/TiN/Si structure device is fabricated. In situ transmission electron microscopy (TEM) and current–voltage (I–V) characteristic demonstrate that the lamella device shows a volatile RS behavior with a threshold switching at ≈ ± 0.4 V. In situ scanning transmission electron microscopy (STEM) experiments with electron energy loss spectroscopy (EELS) reveal that the charge carriers such as oxygen vacancies migrate under positive/negative DC bias and modulate Schottky barriers at the top and bottom metal/semiconductor interfaces. The RS mechanism of the lamella device is based on the Schottky barriers modulation and Joule heating assisted electric field triggered thermal runaway (FTTR) occurred at the metal/semiconductor interfaces. The fundamental insights gained from this study presents a perspective on interface-type RS devices processing and opens up new technological opportunities of fabricating ultra-low-energy memristive devices.