SiC wafers are used as substrates for m-V nitrides growth. 6H-and 4H-SiC boules were grown by the Modified Lely method elaborated at the St.-Petersburg Electrotechnical University. Formation of stress and misoriented areas in SiC crystals has been investigated. The chloride-transport process was employed for the growth of AlN on SiC substrates using an open (p=1 atm) horizontal silica multichannel reactor. High-perfect single crystalline AlN layers were deposited at the growth temperatures above 1150 C and growth rate about 0.1...0.5 mum/min. Single crystalline layers of AW on large SiC substrates with misoriented areas have been successfully obtained.