Notably, a recent study on the surface properties of the substrate comparing h-BN growth using diborane (B₂H₆) on a-cut and c-cut Al2O3 revealed the former to be less likely to modify under growth conditions in the absence of an AlN buffer layer. Its noteworthy that when B₂H₆, a carbon free boron precursor, was used, as opposed to trimethylboron (TMB) and triethylboron (TEB), to deposit BN without nitridizing the sapphire, h-BN films are observed. This study aims to investigate possible growth of sp 2 -BN using thermal CVD, comparing the difference of growth on a-cut, r-cut, m-cut and c-cut substrates. This growth is done using two different boron precursors TMB and TEB which have been investigated in previous studies. Crystalline growth in the polytype r-BN was observed in these studies. The most suitable substrates for specific growth applications will be realized as we identify the major characteristic difference between each substrate.