Shower Plate, Method for Manufacturing the Shower Plate, Plasma Processing Apparatus using the Shower Plate, Plasma Processing Method and Electronic Device Manufacturing Method

• US 20100230387A1
• Filed: 06/13/2007
• Published: 09/16/2010
• Est. Priority Date: 06/13/2006
• Status: Active Grant

• Current Assignee: National University Corporation Chiba University, Tokyo Electron Limited
• Original Assignee: National University Corporation Chiba University, Tokyo Electron Limited
• Inventors: Ishibashi, Kiyotaka, Ohmi, Tadahiro, Goto, Tetsuya, Okesaku, Masahiro
• Granted Patent: US 8,372,200 B2
• Time in Patent Office: Days
• US Class Current: 216/69
• CPC Class Codes: B05B 1/18 Roses; Shower heads with means for adding soap or the like E03C1/046; jet regulators E03C1/08
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45568 Porous nozzles
• CPC Class Codes: C23C 16/511 using microwave discharges
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow

Abstract

Occurrence of a back-flow of plasma or ignition of gas for plasma excitation in a longitudinal hole portion can be prevented more completely, and a shower plate in which efficient plasma excitation is possible is provided. In shower plate 105, which is arranged in processing chamber 102 of a plasma processing apparatus and discharges gas for plasma excitation into processing chamber, porous-gas passing body 114 having a pore that communicates in the gas flow direction is fixed onto longitudinal hole 112 used as a discharging path of gas for plasma excitation. The pore diameter of a narrow path in a gas flowing path formed of a pore, which communicates to porous-gas passing body 114, is 10 μm or lower.

Claims

1. A shower plate, which discharges gas for plasma excitation for generating plasma in a plasma processing apparatus, the shower plate being arranged at the plasma processing apparatus, the shower plate comprising:

a porous-gas passing body having a pore, which communicates in a gas flow direction,

wherein the porous-gas passing body is disposed in a longitudinal hole used as a discharging path of the gas for plasma excitation and a pore diameter of a narrow path in a gas flowing path formed by the pore which passes through the porous-gas passing body is not greater than 10 μ

m.

2. The shower plate of claim 1,

wherein the porous-gas passing body is structured by an alumina based material having a dielectric loss being not greater than 1×

10<sup>−

3</sup>, an average diameter of a crystal being not greater than 10 μ

m, a pore rate being a range of 20 to 75%, an average pore diameter being not greater than 10 μ

m, a maximum pore diameter being not greater than 75 μ

m and a bent strength being not less than 30 MPa.

3. The shower plate of claim 1,

wherein a gas discharge hole is provided in the gas discharge side of the longitudinal hole, and the porous-gas passing body is arranged at a gas introduction side of the gas discharge hole.

4. The shower plate of claim 3,

wherein an aperture of the gas discharge hole is not greater than two times of a sheath thickness of plasma formed directly under a shower plate.

5. The shower plate of claim 3,

wherein a gas passage hole having a diameter, which is greater than an aperture of the gas discharge hole, is provided continuously in the gas introduction side of the porous-gas passing body.

6. The shower plate of claim 3,

wherein a ceramic member in which a plurality of gas discharge holes has been arranged is provided in a longitudinal hole opened in a shower plate.

8. The shower plate of claim 1,

wherein a gas discharge hole is provided on a gas discharge side of a longitudinal hole opened in the shower plate, and chamfering processing is applied to a corner of a gas introduction side of the longitudinal hole.

15. The shower plate of claim 1,

wherein the porous-gas passing body is attached at least to a leading edge portion of the longitudinal hole by fitting in or by combining with sintering.

16. The shower plate of claim 15,

wherein an upper surface and an undersurface of the porous-gas passing body are both curving toward inside of the plasma processing apparatus in a shape of a convex curve or in a shape of a concave curve.

17. The shower plate of claim 15,

wherein a perimeter except the upper surface and the undersurface of the porous-gas passing body is formed by a fine ceramic layer.

18. The shower plate of claim 15,

wherein a porous-gas passing body being different from the porous-gas passing body, which has a larger pore rate than that of a ceramic member or the porous-gas passing body, in which a gas flow hole is provided, is attached in a longitudinal hole in a gas introduction side of the porous-gas passing body.

19. A manufacturing method of a shower plate, which manufactures the shower plate of claim 1, the manufacturing method comprising:

attaching a porous-gas passing body having an outer diameter, which is shorter by 0˜

−

0.002 mm than an inside dimension of the longitudinal hole by performing fitting.

20. A manufacturing method of a shower plate, which manufactures the shower plate of claim 1, comprising steps of:

attaching a powder molding body, a degreasing body of the powder molding body, or a temporary sintered body of the powder molding body, which is processed into a predetermined shape by molding powder ingredients of a porous-gas passing body, to a longitudinal hole of a green body, which is formed by molding powder ingredients of the shower plate and by processing the longitudinal hole; and

sintering the powder molding body, the degreasing body of the powder molding body, or the temporary sintered body with the green body simultaneously.

21. A manufacturing method of a shower plate, which manufactures the shower plate of claim 1, comprising steps of

attaching a powder molding body, a degreasing body of the powder molding body, or a temporary sintered body of the powder molding body, which is processed into a predetermined shape by molding a powder ingredients of a porous-gas passing body, to a longitudinal hole of degreasing body of a green body, which is formed by molding a powder ingredients of the shower plate and by processing the longitudinal hole;

and

sintering the powder molding body, the degreasing body of the powder molding body, or the temporary sintered body with the degreasing body of the green body simultaneously.

22. A manufacturing method of a shower plate, which manufactures the shower plate of claim 1, comprising steps of

attaching a powder molding body, a degreasing body of the powder molding body, or a temporary sintered body of the powder molding body, which is processed into a predetermined shape by molding a powder ingredients of a porous-gas passing body, to a longitudinal hole of a temporary sintered body of a green body, which is formed by molding a powder ingredients of the shower plate and processing the longitudinal hole;

and

sintering the powder molding body, the degreasing body of the powder molding body, or the temporary sintered body with the temporary sintered body of the green body.

24. A plasma processing apparatus into which the shower plate of claim 1 is disposed.

25. A plasma processing method comprising the steps of:

supplying gas for plasma excitation into a plasma processing apparatus using the shower plate of claim 1;

generating plasma by exciting supplied gas for plasma excitation with microwave; and

performing oxidization, nitriding, oxy nitriding, CVD, etching or a plasma exposure against a substrate using this plasma.

26. A manufacturing method of an electronic device including a process of processing a substrate with the plasma processing method of claim 25.

7. A shower plate, which includes a plurality of gas discharge holes, which discharges gas for plasma excitation, the shower plate being arranged at a plasma processing apparatus and arranged to generate plasma in the plasma processing apparatus,

wherein a length of a gas discharge hole of the plurality of gas discharge holes is longer than a mean free path of an electron in the plasma processing apparatus.

9. A shower plate, which is used for plasma processing apparatus, the shower plate comprising:

a plurality of longitudinal holes provided through the shower plate,

wherein a gas discharge side of each longitudinal hole is blocked by a member provided with a plurality of gas discharge holes and a length of each gas discharge hole is longer than a mean free path of an electron in the plasma processing apparatus.

10. The shower plate of claim 9,

wherein the gas discharge side of the longitudinal hole is narrower than a gas introduction side of the longitudinal hole and the member is provided in the narrow portion, while the member extends to the gas introduction side.

11. The shower plate of claim 9,

wherein the member is formed by ceramics structured by an extrusion mold.

12. The shower plate of claim 9,

wherein a porous-gas passing body having a pore communicating in a gas flow direction is provided so as to touch the plurality of gas discharge holes in a gas introduction side of the longitudinal hole.

13. The shower plate of claim 9,

wherein an aperture of the gas discharge hole is not greater than two times of a thickness of plasma formed directly under the shower plate.

14. The shower plate of claim 12,

wherein an aperture of a pore of the porous-gas passing body is not greater than a sheath thickness of plasma formed directly under a shower plate.

23. A manufacturing method of a shower plate comprising the steps of:

inserting a green body, a degreasing body, a temporary sintered body or a sintered body of a ceramic member, which has a plurality of gas discharge holes or gas flow holes, into a longitudinal hole of a green body, the degreasing body or a temporary sintered body of a shower plate, which has been formed by powder ingredients; and

then,

sintering them simultaneously.