primary gas ring 521 which may or may not direct the gases toward the substrate surface injectors may be connected to the primary gas ring 521 to direct at least some of the gases or gas mixtures into the chamber and toward substrate note that injectors gas rings or other mechanisms for directing process gas toward the wafer are not critical to this invention the sonic front caused by a process gas entering the chamber will itself cause the gas to rapidly disperse in all directions u2014 including toward the substrate process gases exit chamber 503 via an outlet 522 a vacuum pump e g a turbomolecular pump typically draws process gases out and maintains a suitably low pressure within the reactor for the hydrogen treatment step of the invention the hydrogen plasma may be generated by a remote plasma generator the reactive species generated from the plasma may be conveyed to chamber 503 through a feed tube the materials used to contain the plasma and feed tube must be resistant to attacks by the plasma and the feed tube should be kept as short as practical generating the plasma in a remote chamber does not subject the deposition chamber components to the temperature radiation or bombardment of a plasma formed in situ and has operating advantages which are apparent to those skilled in the art in a preferred embodiment hydrogen gas is introduced to the reactor to create the plasma containing hydrogen gas comprising substantially molecular hydrogen.