A SiC crystal growth method comprising: (a) providing a SiC single crystal seed and a polycrystalline SiC source material in spaced relation inside of a growth crucible that is disposed in a furnace chamber, wherein the crucible disposed in the furnace chamber defines a growth ambient; (b) providing in the growth ambient a reactive atmosphere comprising gaseous species capable of chemical binding of background impurities of nitrogen and boron present in the growth ambient and removing said impurities from said growth ambient by means of chemical binding (c) sublimating the SiC source material and transporting the sublimated SiC source material to the SiC seed crystal and precipitating the sublimated SiC source material on the SiC seed crystal causing growth of a SiC Single crystal on the SiC seed crystal in the presence of the reactive atmosphere, while simultaneously removing background impurities of nitrogen and boron from the growth ambient by means of the chemical binding (d) following step (c), changing the atmosphere in the growth ambient to a non-reactive atmosphere and (e) following step (d), introducing vanadium and boron dopants into the growth ambient during sublimation growth of the SiC single crystal on the SiC single crystal seed in the growth ambient thereby sublimation growing a fully compensated semi-insulating PI-type SiC single crystal on the SiC seed crystal, wherein the grown PI-type SiC single crystal has a room-temperature resistivity of at least 10 10 Ohm-cm, and an activation energy of resistivity in the range between approximately 0.9 and 1.5 eV in the temperature range between room temperature and 400° C, measured as defined in the description. (a) providing a SiC single crystal seed and a polycrystalline SiC source material in spaced relation inside of a growth crucible that is disposed in a furnace chamber, wherein the crucible disposed in the furnace chamber defines a growth ambient; (b) providing in the growth ambient a reactive atmosphere comprising gaseous species capable of chemical binding of background impurities of nitrogen and boron present in the growth ambient and removing said impurities from said growth ambient by means of chemical binding (c) sublimating the SiC source material and transporting the sublimated SiC source material to the SiC seed crystal and precipitating the sublimated SiC source material on the SiC seed crystal causing growth of a SiC Single crystal on the SiC seed crystal in the presence of the reactive atmosphere, while simultaneously removing background impurities of nitrogen and boron from the growth ambient by means of the chemical binding (d) following step (c), changing the atmosphere in the growth ambient to a non-reactive atmosphere and (e) following step (d), introducing vanadium and boron dopants into the growth ambient during sublimation growth of the SiC single crystal on the SiC single crystal seed in the growth ambient thereby sublimation growing a fully compensated semi-insulating PI-type SiC single crystal on the SiC seed crystal, wherein the grown PI-type SiC single crystal has a room-temperature resistivity of at least 10 10 Ohm-cm, and an activation energy of resistivity in the range between approximately 0.9 and 1.5 eV in the temperature range between room temperature and 400° C, measured as defined in the description.