Effect of growth condition on micropipe filling of 4H-SiC epitaxial layer

In this study, we studied the effect of growth conditions on micropipe (MP) filling during 4H-SiC epitaxial growth. We found that an MP in an on-axis substrate was filled during epitaxial growth and that this MP was filled with a spiral growth. The MP filling on on-axis substrates had a high probability and was independent of growth conditions. On the other hand, the probability of MP filling of 8° off-axis substrates showed a strong dependence on the growth pressure and the growth rate. The probability of MP filling increased with decreasing growth pressure or increasing growth rate. The probability of MP filling of the C-face was higher than that of the Si-face. From a comparison of a numerical simulation and experimental results, we found that the concentration of Si species just above the substrate was a crucial factor for MP filling.