Reactivity of adducts relevant to the deposition of hexagonal BN from first-principles calculations

• DOI: 10.1016/j.cplett.2013.07.077
• Publication Date: 2013-08-05T23:01:36Z
• Authors: R.R.Q. Freitas; G.K. Gueorguiev; F. de Brito Mota; C.M.C. de Castilho; S. Stafström; A. Kakanakova-Geo...
• Keywords: Reactivity; Deposition

First-principles calculations, which also implement the nudged elastic band (NEB) code, are performed to investigate (i) the stability of the (C2H5)3B:NH3 adduct formed by the initial precursor molecules triethylborane (C2H5)3B and ammonia NH3 in the metal–chemical-vapor-deposition (MOCVD) of hexagonal BN, and (ii) the energy barrier to the first ethane elimination through consistent unimolecular, ammonia-assisted, and adduct-assisted reaction pathways. Comparison is done with the reference case of the (CH3)3Al:NH3 adduct, notoriously known for its high degree of stability and reactivity, which determines an overall severe parasitic gas-phase chemical reaction mechanism in the deposition of AlN.