Formation of micropipes in SiC under kinetic aspects

We measure the radii of micropipes at the {0001} surface of modified Lely grown 6H-SiC and the total step height of the accompanying growth spirals by using atomic force microscopy. The micropipes lie in the center of spirals; the total step height ranges between one and 19 unit-cells (1.5-28.5 nm). We fit Frank's theory of hollow core dislocations as modified with regard to kinetic effects by Cabrera and Levine to these experimental results and obtain values for surface energy and supersaturation near the emergence point of the micropipe.