Characterization of a self-aligned RTD using a SiNx sidewall process for high-speed applications.

In this article, an InP-based self-aligned resonant-tunneling-diode (RTD) using a SiNX sidewall process has been fabricated and characterized for high-speed microwave applications. A plasma-enhanced dry-etch technique has been used to form a vertical emitter mesa. The measured peak currents are almost constant at a peak voltage due to negligible thermionic emission in a wide temperature range up to 125°C. The extracted series resistance of the fabricated self-aligned RTD is 14.5 Ω, which is reduced by 27% compared with that of the nonself-aligned RTD by reducing the spacing between emitter mesa and collector metal. To the best of authors' knowledge, this is the first attempt to characterize a self-aligned RTD using the dry-etched mesa and the SiNX sidewall structure. [ABSTRACT FROM AUTHOR]