Diamond semiconductor devices for next generation power electronics and quantum sensing applications

Abstract

The diamond semiconductor is an attractive material for both next-generation power electronics due to its high electric field strength and high thermal conductivity, and for quantum sensing applications involving NV (Nitrogen-Vacancy) centers because of their unique optical and spin properties at room temperature.

We have developed JFETs by using maskless selective n⁺-type diamond growth technology. JFETs show very low leakage currents and a steep sub-threshold slope up to 723K, with high breakdown voltages. With the aim of realizing the diamond’s quantum sensing potential, we have been developing negatively charged NV ensemble centers with longer coherence times. The orientation of these NV centers is highly selectively aligned along the [111] axis with a high density. To increase the negatively charged NV centers, we applied a pn junction to the sensing devices.