Steep slope VO₂ switches for wide-band (DC-40 GHz) reconfigurable electronics

Abstract

Introduction: The ultrafast (∼tens of ns switching time) metal-insulator transition (MIT) VO2 switches reported here show excellent RF performance in a very wide frequency range (DC-40 GHz), relatively low actuation voltage (∼12 V), higher yield and much simpler fabrication process compared to classic RF MEMS counterparts. For the first time, CMOS compatible VO2 microwave switches on high resistivity silicon (HR-Si) substrate are successfully fabricated, overcoming traditional inhomogeneity issues of the SiO2/Si film ascribed to lattice mismatch [1] which used to show less sharp MIT than with Al2O3 substrates [2]. We demonstrate VO2 on SiO2/Si technology presenting 100% yield for switches with flat -0.6 dB S21-ON response and S 21-OFF better than -10 dB across the entire operating range performing better than state-of-the-art for such wide frequency range (2.95 dB up to 13.5 GHz [3]). Furthermore, the devices withstand 109 voltage actuation cycles without failure or significant degradation in S21-ON (limited to 107 cycles in [4]). The proposed solid-state MIT switches open new design and performance opportunities for wideband reconfigurable electronics and tunable RF filters, compared to state-of-the-art RF MEMS. © 2014 IEEE.