Substrate dependent resistive switching in amorphous-HfO memristors: an experimental and computational investigation

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 8; no. 15; pp. 592 - 511
• Main Authors: Basnet, Pradip, Pahinkar, Darshan G, West, Matthew P, Perini, Christopher J, Graham, Samuel, Vogel, Eric M
• Format: Journal Article
• Language: English
• Published: 16.04.2020
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c9tc06736a

While two-terminal HfO x ( x < 2) memristor devices have been studied for ion transport and current evolution, there have been limited reports on the effect of the long-range thermal environment on their performance. In this work, amorphous-HfO x based memristor devices on two different substrates, microscopic glass (∼1 mm) and thin SiO 2 (280 nm)/Si, with different thermal conductivities in the range from 1.2 to 138 W m −1 K −1 were fabricated. Devices on glass substrates exhibit lower reset voltage, wider memory window and, in turn, a higher performance window. In addition, the devices on glass show better endurance than the devices on the SiO 2 /Si substrate. These devices also show non-volatile multi-level resistances at relatively low operating voltages which is critical for neuromorphic computing applications. A multiphysics COMSOL computational model is presented that describes the transport of heat, ions and electrons in these structures. The combined experimental and COMSOL simulation results indicate that the long-range thermal environment can have a significant impact on the operation of HfO x -based memristors and that substrates with low thermal conductivity can enhance switching performance. Long-range thermal environment makes significant impact on resistive switching in amorphous-HfO x ( x ∼ 1.8) memristors; and the substrate of low thermal conductivity improved both the digital and analog switching performance.