An On-Chip Nanoscale Vacuum Sensor Based on Electroformed Silicon Oxide

Vacuum sensors with small footprint, high sensitivity and wide detection range are important for the vacuum measurements in small space. Here, we report a new on-chip nanoscale vacuum sensor (NVS) based on electroformed silicon oxide with the structure of a nanoscale gap between two graphene electrodes on SiO2 substrate. The electrical resistance of the NVS increases exponentially by a magnitude of two orders with air pressure increasing from ~10−1 Pa to ~104 Pa. The increase of O2 partial pressure is responsible for the resistance increase of electroformed silicon oxide, where a Si-SiOx-Si tunneling diode is formed. The advantages of nanoscale size, simple structure, high sensitivity, direct electrical readout and wide detection range make the NVS promising for vacuum measurement of microscale space.