Interior antenna for substrate processing chamber

1. An interior antenna for coupling RF energy to a plasma in a process chamber having a wall, the antenna comprising:

(a) a coil having a face exposed to the plasma in the chamber, the coil comprising a substantially circular section and first and second radially inwardly bent sections that abut one another and have a gap therebetween;

(b) a plurality of standoffs to support the coil at a spacing from the wall of the process chamber, at least one standoff located on the first and second radially inwardly bent sections of the coil, the at least one standoff comprising a terminal extending out of the coil and through which electrical power is applied to the coil from an external power source, the terminal comprising (i) a conductor receptacle to receive a power connector through which electrical power is applied to the coil, the conductor receptacle having a first length L 1 ; and (ii) a conducting jacket around the conductor receptacle, the conducting jacket having a second length L 2 that is smaller than the first length L 1 ;

(c) a dielectric isolator; and

(d) a conductor cup about each standoff having the terminal, the conductor cup having extensions that rest on the dielectric isolator.

2. An antenna according to claim 1 wherein L 2 is smaller than L 1 by at least about 0.5 mm.

3. An antenna according to claim 1 wherein L 2 is smaller than L 1 by from about 0.5 mm to about 2.5 mm.

4. An antenna according to claim 1 wherein is L 1 is from about 7 mm to about 12 mm.

5. An antenna according to claim 1 wherein L 2 is from about 6 mm to about 10 mm.

6. An antenna according to claim 1 wherein the conductor cup comprises a sidewall having an inner diameter that is sufficiently large to provide a sidewall gap between the sidewall and the conducting jacket.

7. An antenna according to claim 1 wherein the conductor cup further comprises an inside circumferential edge and a bottom wall at a depth from the inside circumferential edge that is sufficiently large to provide a bottom wall gap between the bottom wall and the terminal.

8. An antenna according to claim 1 wherein L 2 is from about 6 mm to about 10 mm.

9. An antenna according to claim 1 wherein the first and second radially inwardly bent sections lie in substantially the same plane.

10. An interior antenna for coupling RF energy to a plasma in a process chamber having a wall, the antenna comprising:

(a) a coil having a face exposed to the plasma in the chamber, the coil comprising a substantially circular section and first and second radially inwardly bent sections that abut one another and have a gap therebetween;

(b) a plurality of standoffs to support the coil at a spacing from the wall of the process chamber, at least one standoff located on the first and second radially inwardly bent sections of the coil, the at least one standoff comprising a terminal extending out of the coil and through which electrical power is applied to the coil from an external power source, the terminal comprising (i) a conductor receptacle to receive a power connector through which electrical power is applied to the coil, the conductor receptacle having a first length L 1 ; and (ii) a conducting jacket around the conductor receptacle, the conducting jacket having a second length L 2 that is smaller than the first length L 1 by at least about 0.5 mm;

(c) a dielectric isolator; and

(d) a conductor cup about the standoff having the terminal, the conductor cup having extensions that rest on the dielectric isolator.

11. An antenna according to claim 10 wherein L 2 is smaller than L 1 by from about 0.5 mm to about 2.5 mm.

12. An antenna according to claim 10 wherein the conductor cup comprises a sidewall having an inner diameter that is sufficiently large to provide a sidewall gap between the sidewall and the conducting jacket.

13. An antenna according to claim 10 wherein the conductor cup further comprises an inside circumferential edge and a bottom wall at a depth from the inside circumferential edge that is sufficiently large to provide a bottom wall gap between the bottom wall and the terminal.

14. An interior antenna for coupling RF energy to a plasma in a process chamber having a wall, the antenna comprising:

(a) a single turn coil having a face exposed to the plasma in the chamber, the single turn coil comprising a substantially circular section and first and second radially inwardly bent sections that are substantially within a single plane;

(b) a plurality of standoffs to support the coil at a spacing from the wall of the process chamber, at least one standoff located on the first and second radially inwardly bent sections of the coil, the at least one standoff comprising a terminal extending out of the coil and through which electrical power is applied to the coil from an external power source, the terminal comprising (i) a conductor receptacle to receive a power connector through which electrical power is applied to the coil, the conductor receptacle having a first length L 1 ; and (ii) a conducting jacket around the conductor receptacle, the conducting jacket having a second length L 2 that is smaller than the first length L 1 ;

(c) a dielectric isolator; and

(d) a conductor cup about the standoff having the terminal, the conductor cup having extensions that rest on the dielectric isolator.

15. An antenna according to claim 14 wherein L 2 is smaller than L 1 by at least about 0.5 mm.

16. An antenna according to claim 14 wherein the conductor cup comprises a sidewall having an inner diameter that is sufficiently large to provide a sidewall gap between the sidewall and the conducting jacket.

17. An antenna according to claim 14 wherein the conductor cup further comprises an inside circumferential edge and a bottom wall at a depth from the inside circumferential edge that is sufficiently large to provide a bottom wall gap between the bottom wall and the terminal.