VO2 Switch for Electrostatic Discharge Protection

On-chip protection from electrostatic discharge (ESD) and electrical overstress (EOS) is a continuous challenge in the semiconductor industry, requiring significant design costs and die space. Insulator-metal transition (IMT) materials like vanadium dioxide (VO2) could be used as bidirectional, compact voltage snapback devices for ESD protection that are not required to be in the front-end silicon. However, the reliability and response of these materials to ESD is not yet well studied. Here, we perform transmission line pulse (TLP) tests on thin film (50– 150 nm) VO2 devices. These can repeatedly sustain high currents in their metallic state, but still return to insulating once an ESD event is over. Devices with widths from 5 to 50 $\mu \text{m}$ can carry a maximum current ( ${I} _{{\text {t}2}}$ ) from ~1 to over 10 A, equivalent to ~1 to 15 kV of ESD protection. Furthermore, the snapback voltage can be engineered by varying the device length. These results suggest that IMT materials could be promising for use in on-chip ESD/EOS protection.