Embodiments described herein relate to semiconductor and metal substrate surface preparation and controlled growth methods. An example application is formation of an atomic layer deposition (ALD) control layer as a diffusion barrier or gate dielectric layer and subsequent ALD processing. Embodiments described herein are believed to be advantageously utilized concerning gate oxide deposition, diffusion barrier deposition, surface functionalization, surface passivation, and oxide nucleation, among other processes. More specifically, embodiments described herein provide for silicon nitride ALD processes which functionalize, passivate, and nucleate a SiNx monolayer at temperatures below about 300° C.