GaN and AlGaN high-voltage rectifiers grown by metal-organic chemical-vapor deposition

• Published in: Journal of electronic materials Vol. 31; no. 5; pp. 406 - 410
• Main Authors: Zhu, Ting Gang, Chowdhury, Uttiya, Wong, Michael M, Denyszyn, Jonathan C, Dupuis, Russell D
• Format: Journal Article
• Language: English
• Published: Warrendale Springer Nature B.V 01-05-2002
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-002-0092-9

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 mu m, a breakdown voltage over 400 V, and forward voltage as low as 4.5 V at 100 A/cm super(2) are exhibited for a 60- mu m-diameter device. A GaN Schottky diode with a 2- mu m-thick undoped layer exhibits a blocking voltage in excess of [similar to]230 V at a reverse-leakage current density below 1 mA /cm super(2), and a forward-voltage drop of 3.5 V at a current density of 100 A/cm super(2). 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.