Spatially Resolved Thermometry of Resistive Memory Devices

TL;DR

This paper demonstrates the use of Raman thermometry and scanning thermal microscopy to achieve high-resolution, spatially resolved temperature measurements in resistive memory devices, revealing key thermal interface properties.

Contribution

It introduces a combined thermometry approach for nanoscale temperature profiling in resistive memory devices, highlighting thermal boundary resistance and thermopower at interfaces.

Findings

Thermal boundary resistance at GST-SiO₂ interfaces is 30 m²K⁻¹GW⁻¹.

Effective thermopower at GST-Pt interfaces is 350 μV/K.

The techniques enable detailed temperature mapping in lateral PCM devices.

Abstract

The operation of resistive and phase-change memory (RRAM and PCM) is controlled by highly localized self-heating effects, yet detailed studies of their temperature are rare due to challenges of nanoscale thermometry. Here we show that the combination of Raman thermometry and scanning thermal microscopy (SThM) can enable such measurements with high spatial resolution. We report temperature-dependent Raman spectra of HfO$_2$, TiO$_2$ and Ge$_2$Sb$_2$Te$_5$ (GST) films, and demonstrate direct measurements of temperature profiles in lateral PCM devices. Our measurements reveal that electrical and thermal interfaces dominate the operation of such devices, uncovering a thermal boundary resistance of 30 m$^2$K$^{-1}$GW$^{-1}$ at GST-SiO$_2$ interfaces and an effective thermopower 350 $\mu$V/K at GST-Pt interfaces. We also discuss possible pathways to apply Raman thermometry and SThM techniques to nanoscale and vertical resistive memory devices.