Plasma device and plasma generating method

• US 20040095074A1
• Filed: 12/22/2003
• Published: 05/20/2004
• Est. Priority Date: 01/18/2001
• Status: Active Grant

• Current Assignee: Makoto Ando, Masaharu Takahashi, Tokyo Electron Limited
• Original Assignee: Makoto Ando, Masaharu Takahashi, Tokyo Electron Limited
• Inventors: Ando, Makoto, Takahashi, Masaharu, Ishii, Nobuo
• Granted Patent: US 7,243,610 B2
• Time in Patent Office: Days
• US Class Current: 315/111.21
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/3244 Gas supply means

Abstract

A plasma device includes a slot antenna (30) for supplying a high frequency electromagnetic field (F) supplied through a feeding part into a processing vessel (11). The feeding part has a cavity (35) for forming a resonator and converting the fed high frequency electromagnetic field (F) into a rotating electromagnetic field and supplying the rotating electromagnetic field to the slot antenna (30).

Claims

1. A plasma device comprising a slot antenna for supplying a high frequency electromagnetic field supplied through a feeding part into a processing vessel, characterized in that

said feeding part has a cavity for forming a resonator and converting the fed high frequency electromagnetic field into a rotating electromagnetic field and supplying the rotating electromagnetic field to said slot antenna.

2. A plasma device according to claim 1, characterized in that

the plasma device comprises a ring member formed around an opening of the cavity in said slot antenna and having an inner diameter which is the same as that of the cavity.

3. A plasma device according to claim 1, characterized in that the cavity is formed of

a circular conductor member connected to an outer conductor of a coaxial waveguide for feeding a high frequency electromagnetic field, and

a cylindrical conductor member having one end connected to said circular conductor member and the other end that opens in said slot antenna, and

the plasma device comprises

a feeding pin provided at a position separate from a center of said circular conductor member in a radial direction thereof and having one end connected to an inner conductor of said coaxial waveguide, and

a perturbation pin provided at a position that forms a predetermined angle with said feeding pin through a center of said circular conductor and having one end connected to said circular conductor member.

4. A plasma device according to claim 3, characterized in that

the other end of said feeding pin is open.

5. A plasma device according to claim 3, characterized in that

the other end of said feeding pin is connected to an antenna surface having slots which forms said slot antenna.

6. A plasma device according to claim 5, characterized in that

the other end of said feeding pin is provided with a conductive member which forms a frustoconical shape spreading toward the antenna surface.

7. A plasma device according to claim 5, characterized in that

the other end of said perturbation pin is connected to the antenna surface.

8. A plasma device according to claim 5, characterized in that

the other end of said perturbation pin is connected to said cylindrical conductor member.

9. A plasma device according to claim 3, characterized in that

the other end of said feeding pin is connected to said cylindrical conductor member.

10. A plasma device according to claim 9, characterized in that

the other end of said perturbation pin is connected to an antenna surface having slots which forms said slot antenna, or said cylindrical conductor member.

11. A plasma device according to claim 1, characterized in that the cavity is formed of

a circular conductor member connected to an outer conductor of a coaxial waveguide for feeding a high frequency electromagnetic field,

a cylindrical conductor member having one end connected to said circular conductor member and the other end that opens in said slot antenna, and

a conductive member opposedly arranged inside a side wall of said cylindrical conductor member, and

the plasma device comprises

a feeding pin provided at a position separate from a center of said circular conductor member in a radial direction thereof and having one end connected to an inner conductor of a coaxial waveguide.

12. A plasma device according to claim 11, characterized in that

a length of said conductive member in an axial direction of said cylindrical conductor member is substantially ¼

a wavelength of the high frequency electromagnetic field.

13. A plasma device according to claim 11, characterized in that

an end of said conductive member which is close to said slot antenna is molded to form a slope.

14. A plasma device according to claim 13, characterized in that

a length of a main body of said conductive member excluding one end thereof in an axial direction of said cylindrical conductor member is substantially ¼

a wavelength of the high frequency electromagnetic field.

15. A plasma device according to claim 11, characterized in that

the other end of said feeding pin is connected to an antenna surface having slots for forming said slot antenna.

16. A plasma device according to claim 11, characterized in that

the other end of said feeding pin is connected to said conductor member at a position separate from said circular conductor member in an axial direction of said cylindrical conductor member by substantially ¼

a wavelength of the high frequency electromagnetic field.

17. A plasma device according to claim 1, characterized in that the cavity is formed of

an elliptic conductor member connected to an outer conductor of a coaxial waveguide for feeding a high frequency electromagnetic field, and

a cylindrical conductor member with an elliptic section and having one end connected to said elliptic conductor member and the other end that opens in said slot antenna, and

the plasma device comprises

a feeding pin provided at a position separate from a center of said elliptic conductor member in a radial direction thereof to form a predetermined angle with each of major and minor diameters of said elliptic conductor member and connected to an inner conductor of said coaxial waveguide.

18. A plasma device according to claim 1, characterized in that the cavity is formed of

a circular conductor member connected to outer conductors of first and second coaxial waveguides for feeding high frequency electromagnetic fields, and

a cylindrical conductor member having one end connected to said circular conductor member and the other end that opens in said slot antenna, and

the plasma device comprises

a first feeding pin provided at a position separate from a center of said circular conductor member in a radial direction thereof and connected to an inner conductor of said first coaxial waveguide, and

a second feeding pin provided at a position to form a predetermined angle with said first feeding pin through a center of said circular conductor and connected to an inner conductor of said second axial waveguide.

19. A plasma device according to claim 1, characterized in that the cavity is formed of

a circular conductor member connected to an outer conductor of at least one coaxial waveguide for feeding a high frequency electromagnetic field, and

a cylindrical conductor member having one end connected to said circular conductor member and the other end that opens in said slot antenna, and

the plasma device comprises

a patch antenna for radiating the high frequency electromagnetic field fed from said at least one coaxial waveguide into the cavity as the rotating electromagnetic field,

said patch antenna including

said circular conductor member and

a conductor plate opposedly arranged at a predetermined gap from said circular conductor member and connected to an inner conductor of said at least one coaxial waveguide.

20. A plasma according to claim 1, characterized in that the cavity is formed of

one side surface or terminal end face of a rectangular waveguide for feeding a high frequency electromagnetic field, and

a cylindrical conductor member having one end connected to one side surface or terminal end face of said rectangular waveguide and the other end that opens in said slot antenna, and

the plurality of slots for radiating the high frequency electromagnetic field into the cavity as the rotating electromagnetic field are formed in one side surface or terminal end face of said rectangular waveguide.

21. A plasma device according to claim 20, characterized in that

the plurality of slots comprise two slots intersecting at mid points thereof.

22. A plasma device according to claim 20, characterized in that

the plurality of slots comprise two slots arranged separate from each other and extending in directions substantially nearly perpendicular to each other.

23. A plasma generating method of supplying a high frequency electromagnetic field to a slot antenna, and supplying the high frequency electromagnetic field from the slot antenna into a processing vessel, thereby generating a plasma, characterized in that

a high frequency electromagnetic field is fed to a cavity for forming a resonator, the high frequency electromagnetic field is converted into a rotating electromagnetic field, and simultaneously the high frequency electromagnetic field that has been converted into the rotating electromagnetic field is supplied to the slot antenna while resonating in the cavity.

24. A plasma generating method according to claim 23, characterized in that

the cavity is formed of a circular conductor member connected to an outer conductor of a coaxial waveguide, and a cylindrical conductor member having one end connected to the circular conductor member and the other end that opens in a slot antenna,

a feeding pin connected to an inner conductor of the coaxial waveguide is provided in the cavity at a position separate from a center of the circular conductor member in a radial direction thereof,

a perturbation pin connected to the circular conductor member is provided at a position that forms a predetermined angle with the feeding pin through a center of the circular conductor,

a high frequency electromagnetic field is fed to the cavity through the coaxial waveguide,

the high frequency electromagnetic field is converted into a rotating electromagnetic field by means of the feeding pin and the perturbation pin, and simultaneously the high frequency electromagnetic field that has been converted into the rotating electromagnetic field is supplied to the slot antenna while resonating in the cavity, and

the high frequency electromagnetic field is supplied from the slot antenna into a processing vessel, thereby generating a plasma.

25. A plasma generating method according to claim 23, characterized in that

the cavity is formed of a circular conductor member connected to an outer conductor of a coaxial waveguide, a cylindrical conductor member having one end connected to the circular conductor member and the other end that opens in the slot antenna, and a conductive member opposedly arranged inside a side wall of the cylindrical conductor member, such that a section of the cavity perpendicular to an axis of the cylindrical conductor member has a pair of opposing notched portions,

a feeding pin connected to an inner conductor of the coaxial waveguide is provided in the cavity at a position separate from a center of the circular conductor member in a radial direction thereof and separate from a center line of the notched portions of the section of the cavity,

a high frequency electromagnetic field is fed to the cavity through the coaxial waveguide,

the high frequency electromagnetic field is converted into a rotating electromagnetic field by means of the feeding pin and the cavity having the notched portions, and simultaneously the high frequency electromagnetic field that has been converted into the rotating electromagnetic field is supplied to the slot antenna while resonating in the cavity, and

the high frequency electromagnetic field is supplied from the slot antenna into a processing vessel, thereby generating a plasma.

26. A plasma generating method according to claim 23, characterized in that

the cavity is formed of an elliptic conductor member connected to an outer conductor of a coaxial waveguide, and a cylindrical conductor member with an elliptic section and having one end connected to the elliptic conductor member and the other end that opens in a slot antenna,

a feeding pin connected to an inner conductor of the coaxial waveguide is provided in the cavity at a position separate from a center of the elliptic conductor member to form a predetermined angle with each of major and minor axes of the elliptic conductor member,

a high frequency electromagnetic field is fed to the cavity through the coaxial waveguide,

the high frequency electromagnetic field is converted into a rotating electromagnetic field by means of the feeding pin and the cavity having the elliptic section, and simultaneously the high frequency electromagnetic field that has been converted into the rotating electromagnetic field is supplied to the slot antenna while resonating in the cavity, and

the high frequency electromagnetic field is supplied from the slot antenna into a processing vessel, thereby generating a plasma.

27. A plasma generating method according to claim 23, characterized in that

the cavity is formed of a circular conductor member connected to outer conductors of first and second coaxial waveguides, and a cylindrical conductor member having one end connected to the circular conductor member and the other end that opens in a slot antenna,

a first feeding pin connected to an inner conductor of the first coaxial waveguide is provided in the cavity at a position separate from a center of the circular conductor member in a radial direction thereof, and a second feeding pin connected to an inner conductor of the second coaxial waveguide is provided in the cavity at a position that forms a predetermined angle with the first feeding pin through a center of the circular conductor,

high frequency electromagnetic fields having phases different from each other by 90°

are fed to the cavity through the first and second coaxial waveguides,

the high frequency electromagnetic fields fed from the coaxial waveguides are converted into a rotating electromagnetic field, and simultaneously the high frequency electromagnetic fields that have been converted into the rotating electromagnetic field are supplied to the slot antenna while resonating in the cavity, and

the high frequency electromagnetic fields are supplied from the slot antenna into a processing vessel, thereby generating a plasma.

28. A plasma generating method according to claim 23, characterized in that

the cavity is formed of a circular conductor member connected to an outer conductor of at least one coaxial waveguide, and a cylindrical conductor member having one end connected to the circular conductor member and the other end that opens in a slot antenna,

a conductor plate connected to an inner conductor of at least one coaxial waveguide is opposedly arranged in the cavity at a predetermined gap from the circular conductor member, thus forming a patch antenna including the conductor plate and the circular conductor member,

a high frequency electromagnetic field is fed to the patch antenna through at least one coaxial waveguide, thus generating a rotating electromagnetic field in the cavity,

the high frequency electromagnetic field that has been converted into the rotating electromagnetic field is supplied to the slot antenna while resonating in the cavity, and

the high frequency electromagnetic field is supplied from the slot antenna into a processing vessel, thereby generating a plasma.

29. A plasma generating method according to claim 23, characterized in that

the cavity is formed of one side surface or terminal end face of a rectangular waveguide for feeding a high frequency electromagnetic field, and a cylindrical conductor member having one end connected to one side surface or terminal end face of the rectangular waveguide and the other end that opens in the slot antenna,

the high frequency electromagnetic field fed from the rectangular waveguide is radiated into the cavity through the plurality of slots formed in one side surface or terminal end face, thus generating a rotating electromagnetic field,

the high frequency electromagnetic field that has been converted into the rotating electromagnetic field is supplied to the slot antenna while resonating in the cavity, and

the high frequency electromagnetic field is supplied from the slot antenna into a processing vessel, thereby generating a plasma.