High-voltage mesa-structure GaN Schottky rectifiers processed by dry and wet etching

We have fabricated and investigated high-voltage GaN vertical Schottky-barr ier rectifiers grown by metalorganic chemical vapor deposition. A mesageome try Schottky-barrier rectifier having a 5-mum-thick i region, and processed using reactive-ion etching, exhibited a reverse breakdown voltage of -450 V (at 10 mA/cm(2)) and an on-resistance of 23 m Omega cm(2). For comparison , we have also applied wet chemical etching for the fabrication of mesageom etry Schottky-barrier rectifiers. The 2-mum-thick i-region GaN mesa-Schottk y rectifiers showed a breakdown voltage of -310 and -280 V for wet-etched a nd dry-etched devices, respectively, and an on-resistance of 8.2 and 6.4 m Omega cm(2), respectively. These results indicate that the performance of t he wet-etched rectifiers is comparable to or better than that of comparable dry-etched devices. (C) 2000 American Institute of Physics. [S0003-6951(00 )03344-1].