Ultrasmooth single-crystal diamond surfaces by extended ozone exposure
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2025-07-01 |
| Journal | Journal of Vacuum Science & Technology A Vacuum Surfaces and Films |
| Authors | Chao-Ching Chiang, Hsiao-Hsuan Wan, Jian-Sian Li, F. Ren, S. J. Pearton |
| Institutions | University of Florida |
Abstract
Section titled āAbstractāSmoothing of diamond surfaces is a crucial step in several applications, including homogenizing the distance of nitrogen-vacancy centers from the surface in quantum sensing and communication devices or power rectifiers, where there is a need to avoid sharp surface features that might promote premature breakdown. We have found that extended exposure to UV ozone can significantly improve root-mean-square surface roughness (RMS) and eliminate surface spikes present after polishing commercially available p/p+ structures consisting of CVD layers on a bulk substrate. The as-received RMS roughness of 0.63 nm was reduced to 0.19 nm after 180 min of UV-O3 exposure. For titanium Schottky contact rectifiers fabricated on these ozone-exposed surfaces, the breakdown voltage increased from 710 V for 60 min to 1021 V for 120 min of exposure, which appears to be a result of the reduced density of surface spikes that act as field-crowding regions and lower the breakdown voltage. The fabricated rectifiers on the 120 min of exposure have an on-resistance of 12.7 mĪ© cm2 with a power figure-of-merit of 82.1 MW/cm2.