The effect of high-temperature epitaxial SiC layer growth on the structureof porous silicon carbide

Porous silicon carbide layers obtained by electrochemical etching of 6H-SiC at three anode current densities were investigated. X-ray double- and trip le-crystal diffractometry and scanning electron microscopy were used to stu dy the structure of porous SiC layers before and after high-temperature sub limation growth of 6H-SiC epilayers. The density of pores in the structure is found to be independent of the current density in electrochemical etchin g. The effective diameter of pores increases with increasing current densit y, resulting in higher porosity of the structure. High-temperature annealin g modifies the structure without changing the sample porosity. The structur al rearrangement is accompanied by coalescence of single pores and an incre ase in their diameter. (C) 2001 MAIK "Nauka/ Interperiodica".