Proposal for an electrostrictive logic device with the epitaxial oxide heterostructure

Abstract

AbstractThe possible use of electrostrictive materials for information processing devices has been widely discussed because it could allow low-power logic operation by overcoming the fundamental limit of subthreshold swing greater than 60 mV/decade in conventional MOSFETs. However, existing proposals for electrostrictive FET applications typically adopt approaches that are entirely theoretical and simulative, thus lacking practical insights into how an electrostrictive material can be best interfaced with a channel material. Here we propose an electrostrictive FET device, involving the epitaxial oxide heterostructure as an ideal material platform for maximum strain transfer. The ON/OFF switching occurs due to a stress-induced concentration change of oxygen vacancies in the memristive oxide channel layer. Based on finite-element simulations, we show that the application of a minimal gate voltage bias can induce stress in the channel layer as high as 108 N/m2 owing to the epitaxial interface between the electrostrictive and memristive oxide layers. Conductive AFM experiments further support the feasibility of the proposed device by demonstrating the stress-induced conductivity modulation of a perovskite oxide thin film, SrTiO3, that is well known to serve as the substrate for epitaxial growth of other functional oxide layers.