Thermodynamic modelling of the chemical vapour deposition of boron nitridein the B-N-H-He-O system

Thermodynamic analysis of the chemical vapour deposition (CVD) of the diffe rent modifications of boron nitride (hexagonal h-BN, cubic c-BN and wurzite w-BN) was performed for the B-N-H-He-O system using the method of the mini misation of Gibbs free energy. The calculations were carried out for total pressure P-tot = 1.33 Pa in the temperature region of 300 - 2100 K. The com position of the initial gas mixture of borazine (B3N3H6) and helium (with t he oxygen impurity) was varied in a wide range. The results are presented i n the from of CVD phase diagrams. The influence of the oxygen traces on the temperature boundaries of the c-BN deposition field was shown.