Surfing the Growth Parameters in the Quest for Low-Power, Forming-Free, and Highly Stable TiO_x Memristors for...

Understanding the resistive switching (RS) behavior of oxide-based memory devices at nanoscale is crucial for advancement of high-integration density in-memory computing platforms. This study explores a comprehensive growth parameter space to address the RS behavior of pulsed-laser-deposited substoichiometric TiO₂ (TiO_x) thin films in search of tailored nanoscale memristors with low-power consumption and high stability. Conductive-atomic-force-microscopy-based measurements facilitate deciphering the switching behavior at nanoscale, providing a direct avenue to understand the microstructure-property relationships. The present investigation reveals that rutile TiO_x in an optimal stoichiometric configuration exhibits superior RS attributes, enabling forming-free, low-power, and highly stable memory functionalities at nanoscale. By contrast, the expected formation of the Magnéli phase within a highly defective as-grown TiO_x film hinders the occurrence of switching. Detailed analyses yield a comprehensive parametric phase diagram, providing valuable insights to predict the optimal growth parameters for fabricating on-demand TiO_x-based switching devices. As bulk RS attributes do not always translate seamlessly to the nanoscale, present study leads the pathway to develop tailored memristors for nanoscale electronics promoting their integration into ultrahigh-density, low-energy-consuming advanced memory technologies across diverse disciplines including robotics, data storage, and sensing.