Spatially Resolved Thermometry of Resistive Memory Devices

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Resistive and phase-change memory (RRAM and PCM) operation relies on localized self-heating effects.
• Accurate nanoscale thermometry is crucial but challenging for studying these effects.

Purpose of the Study:

• To demonstrate the application of Raman thermometry and scanning thermal microscopy (SThM) for high-resolution nanoscale temperature measurements in memory devices.
• To investigate the thermal properties and interfaces of HfO2, TiO2, and Ge2Sb2Te5 (GST) films.

Main Methods:

• Utilized Raman thermometry to obtain temperature-dependent spectra of HfO2, TiO2, and GST films.
• Employed scanning thermal microscopy (SThM) for direct measurement of temperature profiles in lateral PCM devices.
• Analyzed thermal boundary resistance and effective thermopower at material interfaces.

Main Results:

• Reported temperature-dependent Raman spectra for key memory materials.
• Measured temperature profiles in lateral PCM devices, highlighting the impact of electrical and thermal interfaces.
• Quantified thermal boundary resistance at GST-SiO2 interfaces (28 ± 8 m²K/GW) and effective thermopower at GST-Pt interfaces (350 ± 50 µV/K).

Conclusions:

• Raman thermometry and SThM are effective tools for nanoscale thermometry in memory devices.
• Thermal interfaces significantly influence the operation of RRAM and PCM devices.
• The study provides a foundation for applying these techniques to nanoscale and vertical resistive memory devices.