Methods of making gas distribution members for plasma processing apparatuses
Methods for making gas distribution members for plasma processing apparatuses are provided. The gas distribution members can be electrodes, gas distribution plates, or other members. The methods include fabricating gas injection holes in a gas distribution member by a suitable technique, e.g., a mechanical fabrication technique, measuring gas flow through the gas distribution member, and then adjusting the permeability of the gas distribution member by the same fabrication technique, or by a different technique, e.g., laser drilling. The permeability of the gas distribution member can be adjusted at one or more zones of the member.
1. A method of making a gas distribution member for a plasma processing apparatus, comprising:
fabricating gas injection holes which extend between opposed inlet and outlet surfaces of the gas distribution member;
measuring a total gas flow that exits from the gas injection holes at the outlet surface for each of a plurality of zones of the gas distribution member; and
based on the total gas flows measured for each of the zones, adjusting gas permeability of the gas distribution member at one or more of the zones to achieve a desired gas flow distribution pattern at the outlet surface.
2. The method of claim 1 , wherein the gas distribution member is a showerhead electrode of silicon or silicon carbide.
3. The method of claim 1 , wherein the gas distribution member is a gas distribution plate.
4. The method of claim 1 , wherein, after the adjusting, each of the zones have substantially the same gas permeability such that the gas distribution member can provide a substantially uniform gas flow distribution pattern at the outlet surface.
5. The method of claim 1 , wherein, after the adjusting, at least two of the zones have different gas permeabilities from each other.
6. The method of claim 1 , wherein the gas injection holes are fabricated by a mechanical fabrication technique.
7. The method of claim 1 , wherein at least two of the gas injection holes have different cross-sectional shapes from each other.
8. The method of claim 1 , wherein the adjusting of the gas permeability of the gas distribution member comprises:
determining the difference between the highest total gas flow through a first one of the zones and the total gas flow through at least a second one of the zones; and
in the second zone, (i) modifying at least one gas injection hole to thereby increase gas flow through the modified gas injection hole and/or (ii) fabricating at least one additional gas injection hole, to thereby adjust the gas permeability of the second zone relative to that of the first zone.
9. The method of claim 8 , wherein the fabrication technique used for (i) and/or (ii) is determined based on the total number of holes in the second zone.
10. The method of claim 1 , wherein the adjusting of the gas permeability of the gas distribution member comprises:
determining the difference between a desired total gas flow and the measured total gas flows through each of the zones; and
at each of the one or more zones, (i) modifying at least one gas injection hole to thereby increase gas flow through the modified gas injection hole and/or (ii) fabricating at least one additional gas injection hole, to thereby adjust the gas permeability of the one or more zones based on the desired total gas flow.
11. The method of claim 10 , wherein the fabrication technique used for (i) and/or (ii) is determined based on the total number of holes in the one or more zones.
12. A method of adjusting gas permeability of a gas distribution member for a plasma processing apparatus, comprising:
flowing gas through gas injection holes of a gas distribution member such that the gas exits at an outlet surface of the gas distribution member;
measuring a total gas flow that exits from the gas injection holes for each of a plurality of zones of the gas distribution member; and
based on the total gas flows measured for each of the zones, adjusting the gas permeability of the gas distribution member at one or more of the zones to achieve a desired gas flow distribution pattern at the outlet surface.
13. The method of claim 12 , wherein the gas distribution member is a showerhead electrode of silicon or silicon carbide.
14. The method of claim 12 , wherein the adjusting of the gas permeability of the gas distribution member comprises:
determining the difference between the highest total gas flow through a first one of the zones and the total gas flow through at least a second one of the zones; and
in the second zone, (i) modifying at least one gas injection hole to thereby increase gas flow through the modified gas injection hole and/or (ii) fabricating at least one additional gas injection hole, to thereby adjust the gas permeability of the second zone relative to the gas permeability of the first zone.
15. The method of claim 14 , wherein the fabrication technique used for (i) and/or (ii) is determined based on the total number of holes in the second zone.
16. The method of claim 12 , wherein the adjusting of the gas permeability of the gas distribution member comprises:
determining the difference between a desired total gas flow and the measured total gas flows through each of the zones; and
at each of the one or more zones, (i) modifying at least one gas injection hole to thereby increase gas flow through the modified gas injection hole and/or (ii) fabricating at least one additional gas injection hole, to thereby adjust the gas permeability of the one or more zones.
17. The method of claim 16 , wherein the fabrication technique used for (i) and/or (ii) is determined based on the total number of holes in the one or more zones.