The present invention generally provides apparatus and method for processing a substrate. Particularly, the present invention provides apparatus and methods to obtain a desired distribution of a process gas. One embodiment of the present invention provides an apparatus for processing a substrate comprising an injection nozzle having a first fluid path including a first inlet configured to receive a fluid input, and a plurality of first injection ports connected with the first inlet, wherein the plurality of first injection ports are configured to direct a fluid from the first inlet towards a first region of a process volume, and a second fluid path including a second inlet configured to receive a fluid input, and a plurality of second injection ports connected with the second inlet, wherein the second injection ports are configured to direct a fluid from the second inlet towards a second region of the process volume.