Search

The synchrotron radiation (SR) phase radiography, optical and scanning electron microscopies (SEM) and color photoluminescence are used to study the interaction of micropipes (MPs) with foreign polytype inclusions in 4H-SiC bulk crystals grown on 6H-SiC substrates. A model of a polytype inclusion interactions with MPs near the free surface of a growing crystal is developed, which has helped in understanding the pore formation and expansion in SiC bulk crystals.

Formation of pores at foreign polytype boundaries in bulk SiC crystals is analyzed by using synchrotron radiation phase-sensitive radiography, optical and scanning electron microscopies and color photoluminescence. The studies have shown that the pore can either be a separate micropipe, or grow up to a certain length or occupy the whole facet of the inclusion depending on the inclusion distortion.

The ramification of micropipes is observed using scanning electron microscopy, optical microscopy, optical microscopy, and synchrotron x-ray radiography. It is shown that the ramification of micropipes in two smaller ones is possible only for micropipes with radii that exceed the equilibrium micropipe radius and is associated with a decrease in the total micropipe surface area.