Epitaxially-Grown GaN Junction Field Effect Transistors
Author | : |
Publisher | : |
Total Pages | : 20 |
Release | : 1999 |
ISBN-10 | : OCLC:727325780 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Epitaxially-Grown GaN Junction Field Effect Transistors written by and published by . This book was released on 1999 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Junction field effect transistors (JFET) 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 (gm) of 48 mS/mm and a maximum source-drain current of 270 mA/mm are achieved on a 0.8 μ m gate JFET device at VGS= 1 V and VDS=15 V. The intrinsic transconductance, calculated from the measured gm and the source series resistance, is 81 mS/mm. The fT and fmax for these devices are 6 GHz and 12 GHz, respectively. These JFETs 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 described, and an estimate for the length of the trapped electron region is given.