Advances in the development of the HTCVD technique for growth of bulk 2-inch diameter 4H SiC crystals are reviewed with demonstration of micropipe density down to 0.3 cm(-2), low crystal bending and X-ray rocking curve widths of 12". High Al doping in p-type substrates enables resistivities down to 0.5 Omega cm without increased micropipe density, while too high N doping causes spontaneous stacking faults formation in annealed n-type substrates. High purity semi-insulating wafers, grown under conditions reducing the incorporation of Si-vacancies, exhibit lower density of vacancy clusters and better properties for microwave device applications.