25 GHz Mixing Demonstration in Nano Air Channel Diodes Enabled by Oblique Deposition

This paper presents the design and fabrication of a nano air channel diode (NACD) utilizing oblique angle deposition process, addressing critical challenges in parasitic capacitance, output current, and IC compatibility. A comprehensive analysis of the device’s operational mechanism is provided, clarifying the emission mechanisms at different bias voltages. I-V measurements indicate that the device exhibits a low turn-on voltage of 0.56 V, a maximum current of 6.06 μA@3.5V and an ultra-low capacitance of 1.74 fF. Frequency mixing performance of the NACDs confirms their functionality near millimeter-wave (mmW) frequency band for the first time. The device demonstrates effective mixing performance across a wide frequency range, from low frequencies up to 25 GHz, underscores its good potential for high-frequency applications.