Indiscriminate revelation of dislocations in single crystal SiC by inductively coupled plasma etching

To reveal dislocations in SiC wafers, conventionally, molten KOH etching method has been widely used. However, when highly doped sites exist on the wafer, the molten KOH etching method is not applicable owing to the enhanced isotropic electrochemical etching phenomenon. In this study, plasma etching is first applied to reveal dislocations in a 4H-SiC wafer with both highly doped and lightly doped areas. The mechanisms of dislocation revelation by dry etching have been theoretically analyzed and it has been revealed that the dislocation revelation ability of dry etching is highly related to the temperature of the etching process. The results demonstrate that inductively coupled plasma (ICP) etching can maintain its effectiveness for dislocation revelation of SiC wafers regardless of the doping concentrations. This work offers an alternative approach to indiscriminately and accurately reveal dislocations in SiC wafers.