The incorporation of nitrogen during single crystal growth of silicon carbide via the vapour phase has been studied in the concentration range of 3(.)10(17) cm(-3) less than or equal to c(N) less than or equal to 3(.)10(19) cm(-3). The nitrogen concentration was measured by secondary ion mass spectrometry (SIMS) and the net doping concentration by capacitance-voltage measurements (CV). In general with increasing the ratio N-2/(N-2+Ar) the nitrogen concentration in the crystals also increases resulting in a function of the square root of nitrogen partial pressure. Furthermore the influence of the seed orientation on the nitrogen level was investigated.