Nitrides are normally deposited using an activated NH3 source, such as a plasma source, usually at high substrate temperatures in excess of 500° C. Previous work has shown that ALD occurs at 600° C.-900° C. with a growth rate of 0.7 Å/cycle on sapphire and Si [1]. Above this window, the process was not self limiting. The precursors were triethylborane and ammonia with H2 carrier gas. George and coworkers showed that ALD with a growth rate of ˜1 Å/cycle of BN with BCl3 and NH3 on ZrO2 nanoparticles was possible at 500K, but it was likely with very large exposures. The process was low temperature, but the substrate was ZrO2 [2]. There has also been reports of laser-assisted ALD of BN using BBr3 and NH3 [3], as well as amorphous growth at 400° C. and turbostratic growth at 750° C. [4]. There are a couple patents from Samsung [5, 6] that discuss forming SiBN thin films with three precursors as well as forming nano-laminate structures of Si3N4 and BN, but these mainly discuss the formation of the films and nano-laminate structures using activated NH3 species or only on semiconducting substrates. There has also been recent work that shows low temperature ALD of hexagonal BN, but using an activated N2/H2 plasma [7].
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