Nanocrystalline diamond capped AlGaN/GaN high electron mobility transistors via a sacrificial gate process
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2016-03-02 |
| Journal | physica status solidi (a) |
| Authors | Marko J. Tadjer, Travis J. Anderson, Tatyana I. Feygelson, Karl D. Hobart, Jennifer K. Hite |
| Institutions | United States Naval Research Laboratory |
| Citations | 25 |
Abstract
Section titled “Abstract”Top-side integration of nanocrystalline diamond films in the fabrication sequence of AlGaN/GaN high electron mobility transistors is demonstrated. Reliable oxygen plasma etching of the diamond capping layer, required for a diamond-before-gate process, was implemented by using a sacrificial SiN “dummy” gate. Hall characterization showed minimal (∼6%) reduction in sheet carrier density and commensurate increase in sheet resistance, while maintaining mobility and on-state drain current density. Off-state drain current and threshold voltage were increased, likely by fluorination of the AlGaN surface after removal of the sacrificial gate, even though a 20 nm thick Al2O3 layer was used as a SF6-plasma etch stop. Pulsed IDS and on-resistance were improved, indicating that a 10 nm SiN/500 nm NCD could offer improved AlGaN surface passivation compared to a more conventional 100 nm thick PECVD SiN film.