Methods for preparing a substrate for a subsequent film formation process are described. Methods for preparing a substrate for a subsequent film formation process, without immersion in an aqueous solution, are also described. A process is described that includes disposing a substrate into a process chamber, the substrate having a thermal oxide surface with substantially no reactive surface terminations. The thermal oxide surface is exposed to a partial pressure of water above the saturated vapor pressure at a temperature of the substrate to convert the dense thermal oxide with substantially no reactive surface terminations to a surface with hydroxyl surface terminations. This can occur in the presence of a Lewis base such as ammonia.