Post Annealing Etch Process for Improved Reverse Characteristics of 4H-SiC Diode
The effects of post annealing etch process on electrical performances of a 4H-SiC Schottky diodes without any edge termination were investigated. The post etch was carried out using various dry the dry etch techniques such as Inductively Coupled Plasma (ICP) and Neutral Beam Etch (NBE) in order to eliminate suspicious surface damages occurring during a high temperature ion activation process. The leakage current of diodes treated by NBE measured at -100V was about one order lower than that of diode without post etch and a half times lower than that of diode treated by ICP without a significant degradation of forward electrical characteristics. Based on the above results, the post annealing process was adapted to a junction barrier Schottky diode with a field limiting ring. The blocking voltages of diode without post annealing etch and diodes treated by ICP and NBE were -1038V, -1125V, and -1595V, respectively.
Amador Pérez-Tomás, Philippe Godignon, Miquel Vellvehí and Pierre Brosselard
I. H. Kang et al., "Post Annealing Etch Process for Improved Reverse Characteristics of 4H-SiC Diode", Materials Science Forum, Vols. 615-617, pp. 663-666, 2009