Fabrication of CMOS-compatible abrupt electronic switches based on vanadium dioxide

Vanadium dioxide thin films were deposited on amorphous SiO2-coated Si substrates, by reactive magnetron sputtering at 490 °C of a pure vanadium target. The deposition parameters were optimized in order to maximize the resistivity modulation due to the metal–insulator transition. The best results were obtained working at an operating pressure of 2 · 10−3 mbar, a constant argon flow of 12.5 sccm and a starting oxygen flow of 2.41 sccm with a feedback control to keep constant the oxygen partial pressure in the sputtering chamber. This allowed to observe for the first time an electrically induced metal–insulator transition with a resistance ratio as high as 824.8 for sputtered VO2 on SiO2/Si substrates.