PLASMA PROCESSING APPARATUS AND METHOD

Abstract

There is provided a plasma processing apparatus in which a microwave is propagated into a dielectric body disposed at a top surface of a process chamber through a plurality of slots formed in a bottom face of a rectangular waveguide to excite a predetermined gas supplied into the process chamber into plasma by electric field energy of an electromagnetic field formed on a surface of the dielectric body, to thereby generate plasma with which a substrate is processed, wherein a top face member of the rectangular waveguide is formed of a conductive, nonmagnetic material and is disposed so as to be movable up and down relative to the bottom face of the rectangular waveguide. To change a wavelength in the rectangular waveguide, the top face member of the rectangular waveguide is moved up and down relative to the bottom face of the rectangular waveguide according to conditions of the plasma processing performed in the process chamber, such as gas species, pressure, and a power of the microwave of a microwave supplier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view (X-X cross section in FIG. 2) showing a schematic construction of a plasma processing apparatus according to an embodiment of the present invention;

FIG. 2 is a bottom view of a lid;

FIG. 3 is an enlarged vertical cross-sectional view (Y-Y cross section in FIG. 2) showing a part of the lid;

FIG. 4 is an enlarged view of a dielectric body seen from under the lid;

FIG. 5 is a vertical cross-sectional view of the dielectric body taken along the X-X line in FIG. 4;

FIG. 6 is an explanatory view of an embodiment where second gas ejecting ports are disposed lower than first gas ejecting ports;

FIG. 7 is a vertical cross-sectional view showing an embodiment where the inside of a slot is divided in a vertical direction and a plurality of dielectric members of different kinds are disposed therein;

FIG. 8 is a vertical cross-sectional view showing an embodiment where the inside of the slot is divided in a lateral direction and a plurality of dielectric members of different kinds are disposed therein;

FIG. 9 is a graph showing results obtained in an example when a change of film thickness depending on the distance from an end of the rectangular waveguide is studied while the height of a top face of a rectangular waveguide is changed; and

FIGS. 10( a), 10(b) are explanatory views schematically showing the position of an electric field generated in the rectangular waveguide when the height of the top face of the rectangular waveguide is changed.

Claims

1. A plasma processing apparatus in which a microwave is propagated into a dielectric body disposed at a top surface of a process chamber through a plurality of slots formed in a bottom face of a rectangular waveguide to excite a predetermined gas supplied into the process chamber into plasma by electric field energy of an electromagnetic field formed on a surface of the dielectric body, to thereby generate plasma with which a substrate is processed, wherein a top face member of said rectangular waveguide is formed of a conductive, nonmagnetic material and is disposed so as to be movable up and down relative to the bottom face of said rectangular waveguide.

2. The plasma processing apparatus according to claim 1, wherein at least one opening is provided in an upper face of said rectangular waveguide, and said top face member is inserted in said rectangular waveguide so as to be movable up and down by means of a member inserted in said opening.

3. The plasma processing apparatus according to claim 1, comprising a mechanism to move up and down said top face member of said rectangular waveguide relative to the bottom face of the rectangular waveguide.

4. The plasma processing apparatus according to claim 3, wherein said mechanism includes a rod moving up and down said top face member and a guide rod constantly keeping said top face member parallel to said bottom face.

5. The plasma processing apparatus according to claim 4, wherein the guide rod has calibrations representing a height h of said top face member from said bottom face of said rectangular waveguide.

6. The plasma processing apparatus according to claim 1, wherein a plurality of rectangular waveguides are disposed in parallel to each other above said process chamber.

7. The plasma processing apparatus according to claim 1, wherein said plurality of slots are arranged in said bottom face of said rectangular waveguide at equal intervals.

8. The plasma processing apparatus according to claim 1, wherein a plurality of dielectric bodies are attached to said rectangular waveguide, and one or more of said slots are provided in said bottom face for each of said dielectric bodies.

9. The plasma processing apparatus according to claim 8, wherein one or more gas ejecting ports are provided, for supplying the predetermined gas into said process chamber, around each of said plurality of dielectric bodies.

10. The plasma processing apparatus according to claim 9, wherein said gas ejecting port is provided in a support member supporting said dielectric body.

11. The plasma processing apparatus according to claim 8, wherein one or more first gas ejecting ports are provided, for supplying a first predetermined gas into said process chamber, and one ore more second gas ejecting ports are provided, for supplying a second predetermined gas into said process chamber, around each of said plurality of dielectric bodies.

12. The plasma processing apparatus according to claim 11, wherein one of said first gas ejecting port and said second gas ejecting port is disposed lower than the other.

13. The plasma processing apparatus according to claim 1, wherein a power of said microwave is 1 W/cm2 to 4 W/cm2.

14. The plasma processing apparatus according to claim 1, wherein said dielectric body has at least one protrusion and at least one recession at the outer bottom surface thereof.

15. The plasma processing apparatus according to claim 1, wherein a dielectric member is disposed in each of the slots.

16. A plasma processing method in which a microwave is propagated into a dielectric body disposed at a top surface of a process chamber through a plurality of slots formed in a bottom face of a rectangular waveguide to excite a predetermined gas supplied into the process chamber into plasma by electric field energy of an electromagnetic field formed on a surface of the dielectric body, to thereby generate plasma with which a substrate is processed, wherein a wavelength of said microwave in said waveguide is controlled by moving up and down a top face member of said rectangular waveguide relative to the bottom face of said rectangular waveguide.

17. The plasma processing method according to claim 16, wherein said top face member of said rectangular waveguide is moved up and down relative to said bottom face of said rectangular waveguide according to a condition of the plasma processing.