A study was made of the structural transformation of screw dislocations during the gas-phase epitaxial growth of 4H-type material. It was confirmed, on the basis of the numbers and features of the etch pits on a surface (following KOH treatment) that some micropipes were closed in the epitaxial layer, and were divided into several elementary screw dislocations. The magnitude of the Burgers vectors of micropipes in 4H-type substrates was considered with regard to the numbers of elementary screw dislocations which were generated by micropipe closing. A depth analysis revealed that most micropipe closing events occurred in the initial stages of epitaxial growth.

Structural Transformation of Screw Dislocations via Thick 4H-SiC Epitaxial Growth. I.Kamata, H.Tsuchida, T.Jikimoto, K.Izumi: Japanese Journal of Applied Physics - 1, 2000, 39[12A], 6496-500