High pressure spatial chemical vapor deposition system and related process

A method for forming a film on a substrate, the method comprising:

• translating the substrate in a circular path through a plurality of process chambers of a material deposition apparatus, each process chamber containing a different source gas comprising a volatile reactive species;
• consecutively exposing the substrate to the process chambers in a sequential manner as the substrate translates in the circular path;
• forming a first film layer on the substrate at a first system pressure during a first period of time;
• forming a second film layer on the first film layer at a second system pressure during a second period of time, the second pressure being different than the first pressure;
• forming a boundary layer adjacent to the substrate beneath the process chambers;
• and
• mixing the source gases from each process chamber in the boundary layer;
• wherein the source gases are partially reacted when exposed to the substrate with each pass allowing the source gases including some unreacted gas to carry over in the boundary layer to the next succeeding chamber for reaction;
• wherein the film gradually grows in thickness on the substrate with each successive pass and exposure of the substrate to the volatile reactive species in the source gases of the process chambers;
• and
• wherein a thickness of the boundary layer is controlled by a plurality of separating barriers which isolates each of the process chambers from every other process chamber, the separating barriers each comprising a bottom edge which is spaced apart from a top surface of a heated susceptor supporting the substrate by a vertical separation distance, the separation distance setting a thickness of the boundary layer.