Patent ID: 9540732
Date: 2017-01-10
CPC Classifications: C23C,H01J,H01L

Claim:
1. A gas distribution apparatus used for a plasma processing equipment, comprising a horizontally arranged support plate which is fixedly connected to a top electrode of the plasma processing equipment, a first air inlet passage is provided at a central position of the support plate; a showerhead electrode, which is parallel to the support plate, is fixedly connected below the support plate, a first gas distribution plate is horizontally arranged in a chamber between the support plate and the showerhead electrode, and the first gas distribution plate has a plurality of axial viahole; a central position of the first gas distribution plate is corresponding to the central position of the support plate; wherein at least one circumferential gas-flow groove surrounding the central position of the first gas distribution plate and a plurality of radial gas-flow grooves communicating with the at least one circumferential gas-flow groove are arranged on an upper surface of the gas distribution plate; the plurality of axial viahole are arranged in the at least one circumferential gas-flow groove and the plurality of radial gas-flow grooves; wherein the support plate further comprises a second air inlet passage which is deviated from the central position of the support plate, a distance between the second air inlet passage and the first air inlet passage is larger than a radius of the first gas distribution plate; a second gas distribution plate is further included in the chamber between the support plate and the showerhead electrode, and the second gas distribution plate closely surrounds the first gas distribution plate, and a chamber on top of the first gas distribution plate is separated from that on top of the second gas distribution plate by a sealing ring, the second gas distribution plate includes a plurality of circumferential gas-flow grooves and a plurality of radial gas-flow grooves communicating with the plurality of circumferential gas-flow groove; a plurality of axial viahole are arrange in the plurality of circumferential gas-flow groove and the plurality of radial gas-flow grooves; the second air inlet passage corresponds to one circumferential gas-flow groove of the second gas distribution plate; a density of the axial viahole located in one and the same circumferential gas-flow groove in the second gas distribution plate successively increases outwards along the radial direction of the second gas distribution plate; and the plurality of circumferential gas-flow grooves, a width of the plurality of circumferential gas-flow grooves successively increasing outwards along the radial direction of the second gas distribution plate.