Plasma processing apparatus and plasma processing method

Abstract

At a frame 26 in a microwave plasma processing apparatus 100, numerous horizontal spray gas nozzles 27 formed therein injection holes A and numerous vertical gas nozzles 28 formed therein injection holes B are fixed. A first gas supply means 50 injects argon gas through the injection holes A into an area near each dielectric parts 31a. A second gas supply means 55 injects silane gas and hydrogen gas through the injection holes B into a position at which the gases do not become over-dissociated. The gases injected as described above are raised to plasma with a microwave transmitted through each dielectric parts 31a. Since the vertical gas nozzles 28 are mounted at positions at which they do not block the flow of plasma traveling toward a substrate G, ions and electrons do not collide with the vertical gas nozzles 28 readily.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a sectional view of the microwave plasma processing apparatus achieved in an embodiment of the present invention;

FIG. 2 is a view of ceiling of the processing container achieved in the embodiment;

FIG. 3 is an enlargement of an area around the gas nozzles in FIG. 1;

FIG. 4 shows an example of the structures of the horizontal spray gas nozzles and the vertical gas nozzles (namely, the icicle-shaped gas nozzles);

FIG. 5 shows the relationship between the microwave power and the SiH2 radical generation rate;

FIG. 6 shows another structural example that may be adopted in the icicle-shaped gas nozzles;

FIG. 7 shows yet another structural example that may be adopted in the icicle-shaped gas nozzles; and

FIG. 8 shows yet another structural example that may be adopted in the icicle-shaped gas nozzles.

Claims

1. A plasma processing apparatus, comprising: a dielectric member that allows a microwave propagated through a waveguide and passed through a slot to be transmitted;a plurality of first gas injection members a first injection holes and disposed at predetermined positions at a frame supporting the dielectric members;a plurality of second gas injection members having a second injection holes located lower than the first injection holes and disposed at predetermined positions at the frame so as not to block a flow of plasma onto a workpiece;a first gas supply means that injects a first processing gas to a desired position through the first injection holes at the first gas injection members;a second gas supply means that injects a second processing gas through the second injection holes at the second gas injection members to a position lower than the position at which the first processing gas is injected; anda processing chamber where the workpiece is processed with plasma generated by raising the first processing gas and the second processing gas to plasma with microwaves.

2. The plasma processing apparatus according to claim 1, wherein: the first gas injection members are mounted outside the frame or are installed inside the frame.

3. The plasma processing apparatus according to claim 1, wherein: the second gas injection members are constituted of metal.

4. The plasma processing apparatus according to claim 1, wherein: the second gas injection members each assume the shape of a rod or a plate.

5. The plasma processing apparatus according to claim 1, wherein: the second gas injection members are fixed onto the frame so as to hang down like verticals from the frame parallel to one another.

6. The plasma processing apparatus according to claim 1, wherein: the second gas injection members are disposed at positions at which the second gas injection members do not form a barrier that would block plasma being diffused over the workpiece.

7. The plasma processing apparatus according to claim 1, wherein: the second gas injection members each project out from the frame by 30 mm or less, measured along the longer side thereof.

8. The plasma processing apparatus according to claim 1, wherein: the second injection holes are set at positions at which the second processing gas is injected at a position such that the second processing gas does not become over-dissociated.

9. The plasma processing apparatus according to claim 1, wherein: the first injection holes open near the dielectric member along a direction parallel to the workpiece.

10. The plasma processing apparatus according to claim 1, wherein: the first injection holes open near the dielectric member along a direction perpendicular to the workpiece.

11. The plasma processing apparatus according to claim 1, wherein: the second injection holes open along a direction perpendicular to the workpiece.

12. The plasma processing apparatus according to claim 1, wherein: the second gas injection members each include a porous part; andthe second gas supply means injects the second processing gas into the processing chamber through the second injection holes constituted with a plurality of openings present at the porous part by passing the second processing gas through the porous part formed at each second gas injection member.

13. The plasma processing apparatus according to claim 12, wherein: the porous part constitutes a spherical front end of each second gas injection member.

14. The plasma processing apparatus according to claim 1, wherein: the second gas injection members each have a spherical front end;the second injection holes are formed in a radial pattern at the spherical front end; andthe second gas supply means injects the second processing gas radially into the processing chamber through the second injection holes.

15. The plasma processing apparatus according to claim 1, wherein: at least either the first processing gas or the second processing gas is a mixed gas obtained by mixing a plurality of processing gas constituents; andunless the mixed gas induces an excessive reaction, the first processing gas achieves greater bond energy than the second processing gas.

16. The plasma processing apparatus according to claim 1, wherein: the dielectric member is constituted with a plurality of dielectric parts; andthe dielectric parts each include at least either an concave portion or a convex portion formed at a surface thereof facing opposite the workpiece.

17. A plasma processing method comprising steps for: transmitting through a dielectric member a microwave propagated through a waveguide and passed through a slot;injecting a first processing gas to a desired position within a processing chamber through first injection holes at a plurality of first gas injection members mounted at predetermined positions at a frame supporting the dielectric member;injecting a second processing gas through second injection holes at a plurality of second gas injection members disposed at predetermined positions at the frame so as not to block the flow of plasma toward a workpiece, with the second injection holes set lower than the first injection holes, to a position lower than the position at which the first processing gas is injected; andraising to plasma the first processing gas injected and the second processing gas injected with microwaves and processing the workpiece with the plasma.

18. The plasma processing method according to claim 17, wherein: heat applied to the second gas injection members constituted of metal is dissipated into a cooling water supplied to a cooling water pipe.