(2), since the diffusion rate and the partial pressure of a given molecule control the flux of that molecule to the surface. If that molecule is a CVD precursor, the diffusion rate also controls film deposition rate. From these considerations, we hypothesize that this diffusion phenomenon can be used to improve film uniformity and SC of CVD in recessed features, without reducing reaction probabilities by low temperature or surface inhibitors. We speculate that a molecule with higher mass than the film precursors, and that is inert to the deposition chemistry, could be used as a diffusion enhancement agent (Fig. ) for this approach. A requirement is that it does not introduce impurities in the film.