Quantum Transport in RF Applications: Ab Initio Investigations, Circuit Modeling, and Experimental Validation of Ferroelectric Diodes

In this work, we present ferroelectric metal-insulator-metal (MIM) diodes based on a 7 nm-thick zirconium oxide layer, deposited between two dissimilar electrodes (i.e., platinum and titanium/gold). Owing to the small contact areas (no greater than 4x4 μm2, the fabricated diodes exhibit a cutoff frequency surpassing 173 GHz. Ab initio investigations allowed to predict very accurately the measured DC current-voltage curves, the agreement between simulations and experiments being impressive, thus validating the quantum transport mechanism in macroscopic devices. Further, a rigorous circuit model has been developed through DC and RF measurements, and the voltage responsivity has been evaluated at different frequencies and input power levels. In the absence of any matching network, the standalone MIM diodes exhibit a record responsivity of almost 11,200 V/W at 2.45 GHz.