Study of the concentration distribution of SiC vapour in the crystal growth zone

In the present work the gas dynamics in the growth zone of SiC crystals is investigated. It is shown that the propagation of SiC vapour from the growth cavity walls towards the lids is effected by diffusion. On this basis the calculation of the concentration distribution of SiC vapour, the equilibrium vapour concentration ns and the supersaturation a=[(n−ns)/ ns] × 100% in the crystal growth zone at different radial and axial temperature gradients is carried out by solving the Laplace equation in cylindrical coordinates for a stationary case corresponding to the conditions of crystal growth. The results obtained are compared with the available experimental data which gives a possibility for explaining some of the observed peculiarities during SiC crystal growth from the vapour phase by the sublimation method.