AFM investigation of interface step structures on PVT-grown (0001)Si 6H-SiC crystals

An AFM investigation of entire growth surfaces of PVT grown (0001)Si 6H-SiC crystals has revealed a number of typical growth interface structures. While step flow mode was observed within the central faceted area, step bunching, nano-steps and even atomically rough surfaces were observed within the peripheral convex area. The changes in growth mode are attributed to the variation of the undercooling along the growth interface. A correlation between the interface inclination a in respect to the (0001) plane and the corresponding growth mode has been determined for particular growth conditions (temperature, pressure). A non-uniform radial distribution of the charge carrier concentration n originated from uneven dopants, incorporation has been investigated. The values of dopants concentration obtained from absorption measurements are correlated to different growth modes. (C) 2004 Elsevier B.V. All rights reserved.