Antonio Paone

Steep slope VO 2 switches for wide-band (DC-40 GHz) reconfigurable electronics

This work proves the feasibility of electrically actuated, CMOS compatible, microwave VO₂ switches on SiO₂/Si substrates with low variability, 100% yield, better than 109 cycles lifetime, ultra-steep OFF-ON transition and better RF performance than previously reported VO₂ switches on Al₂O₃ substrates (flat -0.6 dB S_21-ON with -10 dB S_21-OFF at 40 GHz). The extensive characterization of the fabricated switches has led to an optimum design with maximized S_21-ON/S_21-OFF ratio and validation as a promising solution for wideband reconfigurable electronics.

Steep-slope Metal-Insulator-Transition VO2 Switches with Temperature-Stable High ION

This letter reports a detailed experimental investigation of the slope of the current switching between OFF and ON states exploiting the metal-insulator-transition (MIT) in vanadium dioxide devices. The reported devices are CMOS compatible two-terminal switches. We experimentally demonstrate for the first time the very little dependence on temperature of the steep slope of these switches, ranging from 0.24 mV/decade at room temperature, to 0.38 mV/decade at 50 °C. The fabricated devices show excellent ON-state conduction, with ION > 1.8 mA/μm or RON <; 3 mΩ/μm, for the whole range of investigated temperatures (from room temperature to the MIT transition temperature), which recommends them as future candidates for steep-slope, highly conductive, and temperature-stable switches.

Tunable capacitors and microwave filters based on vanadium dioxide metal-insulator transition

We report the fabrication, modeling and characterization of novel microwave tunable capacitors based on the metal-insulator transition (MIT) of Vanadium Dioxide (VO2). We present the advantages of VO2-based capacitors over alternative technologies for microwave reconfigurable electronics in terms of ease of integration, design and performance at high frequency. We show the potential of the proposed devices for RF reconfigurable electronics by fabricating a tunable bandstop filter (22.5-19.8 GHz) with insertion loss <; 2 dB up to 40 GHz.

CMOS-compatible abrupt switches based on VO 2 metal-insulator transition

We report an extensive experimental study of CMOS-compatible switches based on vanadium dioxide abrupt metal-insulator transition. We perform scaling studies to provide guidelines for optimization of the geometry of the VO2 device for integration on CMOS circuits, discussing the trade-off between the design parameters and the effect on performance for DC and RF applications. A VO2 thin film with resistivity varying from 5·10-2 Ω·m in the insulating state to 1.5-10-5 Ω·m in the conductive state allowed us to fabricate devices with actuation current ranging from 1.43 to 2.46 mA and resistance in the insulating state ranging from 5.8 kΩ to 35.9 kΩ. We identified a minimum actuation current of 5.75 μA for our technology, in a device miniaturized up to the limits of standard optical lithography. We show through RF measurements and simulations that the performance at high frequency of the switch can be improved using VO2 thin films with higher conductivity values, even if the contrast between the two states is lower.

Investigation of the metal-insulator transition in VO 2 for electronic switches with sub-1mV/decade steep subthreshold slope

We report a thorough investigation of the electrically-induced metal-insulator transition in vanadium dioxide (VO2) for abrupt switching in 2-terminal devices (0.24 mV/dec at 25 °C, 0.38 mV/dec at 50 °C). We exploit the electrothermal actuation model based on Joule heating to model and predict the low temperature dependence of the slope in VO2 switches.