A KOH-based defect etching procedure was developed, for SiC, which comprised in situ temperature measurement and control of the melt composition. As a benefit reproducible etching conditions (calibration plot, etching rate versus temperature and time) were established for the first time. The etching procedure was time-independent, i.e. no alteration in KOH melt composition takes place, and absolute melt temperature values could be set. This advanced KOH etching furnace was described; including the development of a new temperature sensor which was resistant to molten KOH. Up-dated absolute KOH etching parameters were presented for n-type SiC and new absolute KOH etching parameters for low and highly p-type doped SiC, which were used for quantitative defect analysis. The best defect etching recipes were found to be 530C/300s (activation energy: 16.4kcal/mol) and 500C/300s (activation energy: 13.5kcal/mol) for n-type and p-type SiC, respectively.

Optimization of KOH Etching Parameters for Quantitative Defect Recognition in n- and p-Type Doped SiC. S.A.Sakwe, R.Müller, P.J.Wellmann: Journal of Crystal Growth, 2006, 289[2], 520-6