LAUSR

The exceptional performance of diamond-based field-effect transistor technology is not restricted to devices that use single crystalline diamond alone. This letter explores the full potential of the heteroepitaxial diamond field-effect transistor (HED-FET). HED-FET devices were fabricated with a long gate–drain length ( ${L}_{\textsf {GD}}$ ) configuration using C–H bonded channels, and a high maximum current density of 80 mA/mm and a high ${I}_ \mathrm{\scriptstyle ON}/{I}_ \mathrm{\scriptstyle OFF}$ ratio of 10⁹ were achieved. Additionally, the HED-FETs showed an average breakdown voltage of ≥500 V and comparatively high breakdown voltage of more than 1 kV. This letter represents a significant step toward the realization of the potential of widely available heteroepitaxial diamond for use in FET applications.