Initial reaction of silicon precursors with a varying number of dimethylamino ligands on a hydroxyl-terminated silicon (0 0 1) surface

The initial reaction of silicon precursors with a varying number of dimethylamino (single bondN(CH3)2) ligands on a hydroxyl-terminated silicon (0 0 1) surface was investigated using density functional theory. Five silicon precursors were chosen to evaluate their adsorption energy and reaction energy barrier as a function of the number of the single bondN(CH3)2 ligands: silane (SiH4), dimethylaminosilane (SiH3[N(CH3)2]), bis-dimethylaminosilane (SiH2[N(CH3)2]2), tris-dimethylaminosilane (SiH[N(CH3)2]3), and tetrakis-dimethylaminosilane (Si[N(CH3)2]4). The adsorption energy increased with the number of the single bondN(CH3)2 ligands, while the reaction energy barrier showed a parabolic behavior. We found that SiH3[N(CH3)2], SiH2[N(CH3)2]2, and SiH[N(CH3)2]3 could be recommended as the suitable Si precursors due to their high adsorption energies and low reaction energy barriers.