The CVD of Boron Nitride

Boron nitride is usually deposited by the reaction of boron trichloride or boron trifluoride with ammonia  

At a deposition temperature of 1300 C, a low-density boron nitride is obtained (1.5 g/cm ) (theoretical density is 2.28 g/cm ). Density increases with increasing temperature and reaches 2.0 g/cm at 1600°C. Vapor phase precipitation can be a problem in the high-temperature range. 

Reaction 2 is used in an electron cyclotron (ECR) plasma to produce c-BN at 675°C on an experimental basis.Cubic boron nitride has a structure similar to diamond with extreme hardness and chemical resistance and is normally obtained by high-pressure processing. 

Low-temperature deposition is possible from diborane as a boron source  

Another useful deposition reaction is the decomposition of borazine. This is a condensation reaction which produces an amorphous BN with residual hydrogen incorporation  

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M.D. Allendorf and T.H. Osterheld, Chemical Reactions in the CVD of Boron Nitride from BCI3 and NH, Proceedings of I3th International Conference Chemical Vapor Deposotion, Vol.96, No.5, 1996, p.l6. 

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