Epitaxially-grown GaN junction field effect transistors
Junction field effect transistors (JFET's) are fabricated on a GaN epitaxial structure grown by metal organic chemical vapor deposition (MOCVD). The dc and microwave characteristics of the device are presented. A junction breakdown voltage of 56 V is obtained corresponding to the theoretical limit of the breakdown field in GaN for the doping levels used. A maximum extrinsic transconductance (g{sub m}) of 48 mS/mm and a maximum source-drain current of 270 mA/mm are achieved on a 0.8 {micro}m gate JFET device at V{sub GS} = 1 V and V{sub DS} = 15 V. The intrinsic transconductance, calculated from the measured g{sub m} and the source series resistance, is 81 mS/mm. The f{sub T} and f{sub max} for these devices are 6 GHz and 12 GHz, respectively. These JFET's exhibit a significant current reduction after a high drain bias is applied, which is attributed to a partially depleted channel caused by trapped hot-electrons in the semi-insulating GaN buffer layer. A theoretical model describing the current collapse is presented, and an estimate for the length of the trapped electron region is given.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (US)
- Sponsoring Organization:
- National Science Foundation; US Department of Energy
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 20020760
- Journal Information:
- IEEE Transactions on Electron Devices (Institute of Electrical and Electronics Engineers), Journal Name: IEEE Transactions on Electron Devices (Institute of Electrical and Electronics Engineers) Journal Issue: 3 Vol. 47; ISSN 0018-9383; ISSN IETDAI
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fabrication and characterization of GaN junction field effect transistors
GaN Metal Oxide Semiconductor Field Effect Transistors