Patent ID: 8906791

Claim:
A method comprising: providing a wafer substrate to a chamber of an apparatus, the apparatus including a showerhead to deliver a gas to the chamber, a volume, and an isolation valve between the volume and the showerhead, wherein the showerhead includes a gas inlet coupled to the isolation valve at an inlet end of the showerhead and a faceplate at an outlet end of the showerhead; delivering the gas to the volume when the isolation valve is closed to pressurize the volume with the gas, wherein a ratio of a pressure in the volume to a pressure in the chamber is equal to or greater than about 2:1 before opening the isolation valve; opening the isolation valve to allow the gas to flow to the showerhead simultaneous with the gas being continuously delivered to the volume, wherein a substantially spatially uniform flow of the gas across the faceplate of the showerhead is achieved in less than about 0.5 seconds after opening the isolation valve; and forming a material on the wafer substrate, wherein the gas is used for forming the material.