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Transient thermometry and high-resolution analysis of filamentary resistive switches



Jonghan Kwon, Chao-Yang Chen, Abhishek Sharma, Andrea Fantini, Malgorzata Jurczak, James A. Bain, Yoosuf Picard, Marek Skowronski, Andrew Herzing


We present data on the filament size and temperature distribution in Hf0.82Al0.18Ox-based Resistive Random Access Memory (RRAM) devices obtained by transient thermometry and high- resolution transmission electron microscopy (HRTEM). The thermometry shows that the temperature of the permanent conducting filament can reach 1600 K at the onset of RESET at voltage of 0.8 V and power of 40 μW. The size of the filament was estimated at ≈ 1 nm in diameter. Such high temperatures heat up the surrounding oxide, causing it to conduct and carry a significant fraction of the total current. The current spreading results in slowing down the filament temperature increase with higher power. The results of thermometry have been corroborated by HRTEM analysis of the as-fabricated and switched RRAM devices. The functional HfAlOx layer in as-fabricated devices is amorphous. In devices that were switched, we detected a small crystallized region 10-15 nm in size. The crystallization temperature of the HfAlOx was determined to be 870 K in an independent annealing experiment. The size of the crystallite region agrees with thermal modeling based on the thermometry data. Scanning TEM coordinated with electron energy loss spectroscopy detected no changes in the chemical make up of the filament.
ACS Applied Materials and Interfaces


RRAM, thermometry, filament, HRTEM, STEM, EELS


Kwon, J. , Chen, C. , Sharma, A. , Fantini, A. , Jurczak, M. , Bain, J. , Picard, Y. , Skowronski, M. and Herzing, A. (2016), Transient thermometry and high-resolution analysis of filamentary resistive switches, ACS Applied Materials and Interfaces, [online], (Accessed June 18, 2024)


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Created June 28, 2016, Updated October 28, 2022