Effect of a Post-annealing Etch Process on the Electrical\\Performances of 4H-SiC Schottky Diodes

The effects of a post-annealing etch process on the electrical performances of 4H-SiC Schottky diodes without any edge termination were investigated. The post-annealing etch was carried out using two different dry etch techniques: an inductively coupled plasma (ICP) etch and a neutron beam etch (NBE), in order to eliminate suspicious surface damages occurring during a high-temperature ion-activation process. The reverse leakage current of the diode treated by using NBE was about one order lower than that of the diode without a post-etch process and was about half reverse leak-age current of the diode treated by using ICP. In addition, the forward characteristics remained almost the same. These results were attributed to the elimination of damaged surface layers by the NBE process and partly to a lower number of plama-radiation-related defects.