Radio frequency side-gate nanoscale vacuum channel triode

Abstract

Nanoscale vacuum semiconductor devices utilize vacuum as an electron transport medium, offering the advantages of rapid response and immunity to extreme environments. In this study, we present a nanoscale vertical channel vacuum triode with a side-gate structure. The device employs vacuum as the gate insulating medium, which enhances its reliability compared to conventional vertical structure vacuum triodes. Furthermore, the side-gate design reduces the gate input capacitance to approximately 10−18 F, making it more suitable for high-frequency operations. We systematically investigate the impact of structural dimensions on device performance. Simulation results demonstrate that when the dielectric layer thickness is around 35 nm, the maximum transconductance of the device reaches 1.23 μS. Increasing the gate dielectric layer thickness leads to an increase in cut-off frequency but decreases channel current. Smaller gap widths between the cathode and gate result in higher transconductance and cut-off frequencies. However, when the gap width is less than 40 nm, noticeable gate leakage currents occur. Introducing negative offset of alignment between the anode and channel edge enhances transconductance and cut-off frequency but may introduce stability issues. These research findings provide valuable insights for developing high-frequency vacuum triode devices.