Description
Nanoscale vacuum channel devices (NVCDs) enable electrons to travel across a nanoscale vacuum gap with minimal scattering, allowing faster electron transport than conventional solid-state devices. The absence of a solid conduction channel also provides improved tolerance to radiation, high temperatures, and harsh operating environments, making NVCDs promising candidates for next-generation high-frequency applications. Despite these advantages, the high-frequency behaviour of NVCDs remains largely unexplored. Most existing studies focus DC operation, while the limited investigations of frequency response are primarily restricted to vertical device structures. Furthermore, current research predominantly demonstrates individual devices rather than circuit-level integration, leaving the relationship between device geometry, electron transport, and high-frequency performance insufficiently understood.
As a first step toward enabling high-frequency NVCD operation, this work investigates how electrode geometry influences electric field distribution and parasitic capacitance in a lateral NVCD unit cell. Electrostatic simulations evaluated the effects of channel gap, cathode curvature, electrode length, and emitter array density. Unlike most previous studies that assess only the electric field at the cathode tip, this work also examines the field within the middle of the vacuum gap, where electrons accelerate toward the anode. Analysing this region provides additional insight into electron transport and helps determine whether sufficient acceleration can be achieved for stable emission and reliable high-frequency operation.
The results identify the channel gap as the dominant parameter governing both electric field strength and parasitic capacitance. While sharper cathodes produce stronger field enhancement at the emission tip, they also cause rapid field decay within the channel, limiting electron acceleration. A moderate cathode curvature radius of approximately 25 nm provides a better balance by maintaining a high emission field while promoting more uniform acceleration across the vacuum gap. In contrast, electrode length has minimal influence on electric field distribution and parasitic capacitance, indicating greater flexibility for compact lateral NVCD design.
| I am the presenting author | Yes |
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