GaN and AlGaN High-Voltage Rectifiers Grown by Metal-Organic Chemical-Vapor Deposition
Authors: Zhu, Ting Gang; Chowdhury, Uttiya; Wong, Michael M.; Denyszyn, Jonathan C.; Dupuis, Russell D.
Source: Journal of Electronic Materials, Volume 31, Number 5, 1 May 2002 , pp. 406-410(5)
Abstract:In this paper, we report the study of the electrical characteristics of GaN and AlGaN vertical p-i-n junctions and Schottky rectifiers grown on both sapphire and SiC substrates by metal-organic chemical-vapor deposition. For GaN p-i-n rectifiers grown on SiC with a relatively thin "i" region of 2 μm, a breakdown voltage over 400 V, and forward voltage as low as 4.5 V at 100 A/cm2 are exhibited for a 60-μm-diameter device. A GaN Schottky diode with a 2-μm-thick undoped layer exhibits a blocking voltage in excess of ~230 V at a reverse-leakage current density below 1 mA/cm2, and a forward-voltage drop of 3.5 V at a current density of 100 A/cm2. It has been found that with the same device structure and process approach, the leakage current of a device grown on a SiC substrate is much lower than a device grown on a sapphire substrate. The use of Mg ion implantation for p-guard rings as planar-edge terminations in mesageometry GaN Schottky rectifiers has also been studied.
Document Type: Research article
Publication date: 2002-05-01