Patent ID: 8869742

Claim:
A semiconductor wafer processing apparatus, comprising: a chuck including an electrode exposed to a plasma generation volume, the electrode defined to transmit radiofrequency (RF) power to the plasma generation volume, the electrode having an upper surface defined to hold a substrate in exposure to the plasma generation volume, the chuck having a top surface that circumscribes a perimeter of a top surface of the electrode; and a gas distribution unit disposed above the plasma generation volume and in a substantially parallel orientation with respect to the electrode, the gas distribution unit defined to include an arrangement of gas supply ports defined to direct an input flow of a plasma process gas into the plasma generation volume in a direction substantially perpendicular to the upper surface of the electrode, the gas distribution unit further defined to include an arrangement of through-holes that each extend through the gas distribution unit to fluidly connect the plasma generation volume to an exhaust region, wherein each of the through-holes is defined to direct an exhaust flow of the plasma process gas from the plasma generation volume in a direction substantially perpendicular to the upper surface of the electrode, and wherein the gas distribution unit is defined as a plate formed to separate the plasma generation volume from the exhaust region, and wherein each gas supply port in the arrangement of gas supply ports is defined at a lower surface of the plate to provide for distribution of plasma process gas to the plasma generation volume; an outer peripheral structure having a top surface and a bottom surface and formed to extend in a solid form between its top and bottom surfaces, the bottom surface of the outer peripheral structure disposed on the top surface of the chuck, the gas distribution unit disposed on the top surface of the outer peripheral structure, the outer peripheral structure defined to surround and enclose a perimeter of the plasma generation volume such that an uninterrupted fluid seal is present between the bottom surface of the outer peripheral structure and the top surface of the chuck around the perimeter of the plasma generation volume, and such that an uninterrupted fluid seal is present between the top surface of the outer peripheral structure and the gas distribution unit around the perimeter of the plasma generation volume.