Etching Study of SiC Wafers

SiC substrates grown by the sublimation method still have high densities of structural defects such as dislocations, micropipes, low-angle grain boundaries, macrodefects and polytypes. Wet etching was effectively used to study the defects of SiC. Etch pit shapes of defects and their origins were discussed. Most of the defects originate in the initial growth stage. Thus to optimize the early growth conditions especially the temperature distribution is a crucial problem.