US Patent 7020981 Reaction system for growing a thin film

A reactor defines a reaction chamber for processing a substrate. The reactor comprises a first inlet for providing a first reactant and to the reaction chamber and a second inlet for a second reactant to the reaction chamber. A first exhaust outlet removes gases from the reaction chamber. A second exhaust outlet removes gases from the reaction chamber. A flow control system is configured to alternately constrict flow through the first and second exhaust outlets. The reactor chamber is configured to for a diffusion barrier within the reaction chamber.