A vapor flow controller apparatus for delivery of chemical reagent vapors from a liquid phase source material is provided which includes a source container containing the liquid phase source material, a pump to transport the liquid phase source material to a vaporizor module, the pump having a flow rate controller, and the vaporizer module having a source material inlet, a carrier gas inlet, and a vaporized gas outlet. The vaporizer module converts the liquid phase source material to a vapor. The vapor flow controller apparatus further includes a source material conduit for passage of the liquid phase source material from the source container to the source material inlet of the vaporizer module. The vapor flow controller apparatus further includes a carrier gas container containing a carrier gas and having a carrier gas outlet conduit controlled by a mass flow controller.
