Synthesis and structure of chemically vapour-deposited boron nitride
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- Matsuda, T., Uno, N., Nakae, H. et al. J Mater Sci (1986) 21: 649. doi:10.1007/BF01145537
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Chemically vapour-deposited boron nitride (CVD-BN) plates have been synthesized on a graphite substrate by the reaction of the BCl3-NH3-H2 gas system in a deposition temperature (Tdep) range from 1200 to 2000° C, with a total gas pressure (Ptot) which was varied from 5 to 60 torr. The effects ofPtot andTdep on the crystal structure and the microstructure of the CVD-BN plate were investigated. Turbostratic BN(t-BN) was deposited above 10 torr, at anyTdep in the range investigated. The interlayer spacing (c0/2), the crystallite size (Lc) and the preferred orientation (PO) were strongly affected byTdep. The t-BN obtained at lowTdep had largec0/2 and smallLc andPO. AsTdep increased,c0/2 tended to decrease whereasLc increased and thec-plane of the crystallites became oriented parallel to the deposition surface. At aPtot of 5 torr, a mixture of t-BN and h-BN (hexagonal BN) was deposited at anyTdep above 1700° C, and two kinds of t-BN different inc0/2 co-deposited at aTdep below 1600° C. Moreover, it was indicated that r-BN (rhombohedral BN) was included in the deposits obtained at aPtot of 5 torr and aTdep of 1500 to 1600° C.