An On-Chip Microscale Vacuum Chamber with High Sealing Performance Using Graphene as Lateral Feedthrough

On-chip microscale vacuum chambers with high sealing performance and electrical feedthroughs are highly desired for microscale vacuum electronic devices and other MEMS devices. In this paper, we report an on-chip microscale vacuum chamber which achieves a high sealing performance by using monolayer graphene as lateral electrical feedthrough. A vacuum chamber with the dimensions of π × 2 mm × 2 mm × 0.5 mm is fabricated by anodically bonding a glass chip with a through-hole between two Si chips in a vacuum, after monolayer graphene electrodes have been transferred to the surface of one of the Si chips. Benefiting from the atomic thickness of monolayer graphene, the leak rate of Si-glass bonding interface with a monolayer graphene feedthrough is measured at less than 2 × 10^-11 Pa·m³/s. The monolayer graphene feedthrough exhibits a minor resistance increase from 22.5 Ω to 31 Ω after anodic bonding, showing good electrical conductance. The pressure of the vacuum chamber is estimated to be 185 Pa by measuring the breakdown voltage. Such a vacuum is found to maintain for more than 50 days without obvious degradation, implying a high sealing performance with a leak rate of less than 1.02 × 10^-16 Pa·m³/s.