| Title |
[SPECIAL ISSUE] P-GaN Gated AlGaN/GaN E-mode HFET Fabricated with Selective GaN Etching Process |
| Authors |
(Won-Ho Jang) ; (Kwang-Seok Seo) ; (Ho-Young Cha) |
| DOI |
https://doi.org/10.5573/JSTS.2020.20.6.485 |
| Keywords |
AlGaN/GaN heterojunction; p-GaN gate; selective plasma etching |
| Abstract |
An O2 based selective GaN etching process was developed herein for use in p-GaN gated AlGaN/GaN heterojunction field-effect transistor fabrication, where precise control of the p-GaN etching was an important process step that determined the device characteristics. The p-GaN layer was etched by a two-step process: low damage BCl3/Cl2 plasma etching in conjunction with Cl2/N2/O2 based selective etching. A high selectivity of 53:1 for the p-GaN:AlGaN was achieved by the Cl2/N2/O2 plasma etching. The device fabricated by the optimized etching process exhibited excellent enhancement-mode characteristics, i.e., a threshold voltage of 2.45 V, a specific on-resistance of 5.55 mΩ?cm2, an on/off ratio of ~109, and an off-state breakdown voltage of >1100 V. |