Gas supply member, plasma treatment method, and method of forming yttria-containing film

1. A gas supply member forming an electrode in a chamber, the gas supply member comprising:

an electrode constituting member provided with a gas supply passage, the gas supply passage including a gas flow channel and an exhaust port, the exhaust port being connected to a first connection part which is one end portion of the gas flow channel and being provided to a downstream side of the electrode constituting member, the electrode constituting member having a first flat surface at the downstream side; and

an yttria-containing film coating a part of the electrode constituting member, wherein

at least a part of a surface constituting the exhaust port of the electrode constituting member is formed with a curved surface,

the surface constituting the exhaust port and the first flat surface at the downstream side of the electrode constituting member are connected to each other by a smooth curved surface continuously,

a diameter of the exhaust port increases as it goes far from the first connection part with the gas flow channel,

a diameter of the gas flow channel is entirely constant from the one end portion connected to the exhaust portion to the other end portion intersecting with a second flat surface at an upstream side of the electrode constituting member, the second flat surface being parallel with the first flat surface, and

the yttria-containing film is formed on the surface constituting the exhaust port and on the first flat surface at the downstream side of the electrode constituting member and is not formed on an upstream side of the first connection part, the yttria-containing film having a curved surface.

2. The gas supply member according to claim 1 ,

wherein the curved surface is formed near a second connection part between the surface constituting the exhaust port and the first flat surface of the downstream side of the electrode constituting member.

3. The gas supply member according to claim 1 ,

wherein a thickness of the yttria-containing film decreases toward the first connection part.

4. The gas supply member according to claim 1 ,

wherein the gas flow channel has a first diameter, and

an opening diameter at the first flat surface of the downstream side of the electrode constituting member is a second diameter which is larger than the first diameter.

5. The gas supply member according to claim 1 ,

wherein, when a gas exhausted from the exhaust port and changed in the plasma state, the first flat surface of the downstream side of the electrode constituting member faces the gas in the plasma state.

6. The gas supply member according to claim 1 ,

wherein an alumina film is formed on the electrode constituting member, and the yttria-containing film is formed on the alumina film.

7. The gas supply member according to claim 1 ,

wherein the yttria-containing film has a melt-solidified part obtained by melting and solidifying the yttria-containing film from the surface in a range of a thickness of the yttria-containing film.

8. The gas supply member according to claim 1 ,

wherein the first flat surface at the downstream side of the electrode constituting member is parallel to a surface of a processing target to be set in the chamber, the surface of processing target being set to face the electrode constituting member in the chamber.

9. The gas supply member according to claim 1 ,

wherein a thickness at an end portion of an upstream side of the yttria-containing film gradually decreases toward the first connection part.

10. The gas supply member according to claim 1 ,

wherein the gas flow channel has a first diameter,

the exhaust port has a smooth curved surface between the first connection part and the first flat surface at the downstream side of the electrode constituting member, and

a thickness of the yttria-containing film on the exhaust port decreases toward the first connection part.

11. The gas supply member according to claim 1 ,

wherein, in a longitudinal section of the gas supply passage, the first connection part is a boundary between a smooth curved portion of the exhaust port and a linear portion of the gas flow channel.

12. The gas supply member according to claim 11 ,

wherein the yttria-containing film does not have a linear surface in the gas supply passage.

13. The gas supply member according to claim 1 ,

wherein the electrode constituting member is made of aluminum.

14. The gas supply member according to claim 1 ,

wherein the curved surface is formed near a second connection part between the surface constituting the exhaust port and the first flat surface at the downstream side of the electrode constituting member.

15. The gas supply member according to claim 13 ,

wherein a thickness of the yttria-containing film decreases toward the first connection part.