A Comparative Study of Micropipe Decoration and Counting in Conductive and Semi-Insulating Silicon Carbide Wafers

摘要

Micropipes are considered to be one of the most serious defects in silicon carbide (SiC) wafers affecting device yield.Developing a method to count and map micropipes accurately has been a challenging task.In this study,the different etching behavior of conductive and semi-insulating wafers in molten potassium oxide (KOH) is compared.Micropipes and closed-core screw dislocations exhibit different morphology after etching and can be easily distinguished with a polishing process.Based on a new sample preparation procedure and a digital imaging technique,a novel method of efficiently and reliably mapping and counting micropipes in both conductive and semi-insulating SiC wafers is developed.