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

Area of Science:

• Materials Science
• Electrical Engineering
• Microelectromechanical Systems (MEMS)

Background:

• Microscale vacuum chambers are essential for vacuum electronic devices and MEMS.
• Achieving high sealing performance and reliable electrical feedthroughs on-chip remains a challenge.

Purpose of the Study:

• To develop an on-chip microscale vacuum chamber with superior sealing capabilities.
• To utilize monolayer graphene as an effective lateral electrical feedthrough.

Main Methods:

• Fabrication of a vacuum chamber (π × 2 mm × 2 mm × 0.5 mm) using anodic bonding of Si and glass chips in a vacuum.
• Transfer of monolayer graphene electrodes onto a Si chip prior to bonding.
• Measurement of leak rate, electrical resistance of graphene feedthrough, and internal pressure via breakdown voltage.

Main Results:

• Achieved a Si-glass bonding interface leak rate below 2 × 10^-11 Pa·m³/s using monolayer graphene feedthroughs.
• Monolayer graphene feedthrough showed a minor resistance increase from 22.5 Ω to 31 Ω, indicating good electrical conductance.
• The vacuum chamber maintained a pressure of 185 Pa for over 50 days, demonstrating a leak rate < 1.02 × 10^-16 Pa·m³/s.

Conclusions:

• Monolayer graphene serves as an effective lateral electrical feedthrough for on-chip microscale vacuum chambers.
• The developed fabrication method achieves high sealing performance, crucial for microscale vacuum electronic devices.
• This technology offers a promising solution for advanced MEMS and vacuum-based microdevices.