Methods and apparatus for processing an electronic component precursor comprising the steps of contacting a carrier gas with a process chemical stream to entrain the process chemical in the carrier gas thereby forming a fluid stream and injecting at least a portion of additional process chemical into the fluid stream to form a localized region of increased concentration of process fluid is provided. The methods and apparatus also provide injecting a portion of additional carrier gas into the fluid stream to form a diluted region of decreased concentration of process fluid is also provided. The methods and apparatus further provide controlling the concentration of process chemical in the localized region as well as in the fluid stream. Apparatus comprising a first manifold operatively associated with a carrier gas source for receiving a fluid stream formed by the carrier gas and a second manifold in fluid communication with the first manifold for receiving a process chemical and for injecting the process chemical into the fluid stream thereby forming a localized region of increased concentration of process chemical is provided.