On the Dissociative Chemisorption of Tris(dimethylamino)silane on Hydroxylated SiO 2 (001) Surface

We present a first-principles theoretical study on the dissociative chemisorption of tris(dimethylamino)silane (TDMAS) on a hydroxylated SiO 2 (001) surface. The thermochemical energies and activation barriers associated with the elementary surface reaction processes have been calculated. Our results indicate that sequential dissociation of TDMAS can occur only up to the second step with dimethylaminosilylenyl groups anchored on the surface. Further dissociation of these surface species is virtually energetically forbidden under typical atomic layer deposition processing conditions. This would result in an inherently low density and compositionally impure SiO 2 film with a low deposition rate.