Dislocation nucleation in 4H silicon carbide epitaxy

The dislocation nucleation during 4H silicon carbide homoepitaxy has been investigated using chemical etching, optical microscopy, atomic force microscopy, and transmission electron microscopy. Threading edge dislocations formed characteristic arrays of etch pit pairs on the epilayer surface, perpendicular to the off-cut direction. The arrays were nucleated throughout the epitaxy process, had length of between 30 and 600 mum and linear dislocation density of about 1 x 10(3) cm(-1). The Burgers vectors of two dislocations in each pair were consistent with pairs nucleating as half loops and their directions were the same for all dislocations in an array. (C) 2003 Elsevier B.V. All rights reserved.