Plasma generation system having a refractor

1. A plasma generation system, comprising:

a microwave generator for generating microwaves;

a refractor for altering a direction of propagation of the microwaves; and

an electromagnetic unit for applying a magnetic field to plasma formed by the microwaves to generate electron cyclotron resonance (ECR).

2. The system as claimed in claim 1 , wherein the refractor is a dielectric lens.

3. The system as claimed in claim 2 , wherein the dielectric lens is formed of alumina.

4. The system as claimed in claim 1 , wherein the microwave generator comprises:

a radio frequency power source for generating the microwaves;

a waveguide, which is connected to the radio frequency power source, for guiding the propagation of the microwaves; and

a polarizer, which is placed at an outlet of the waveguide, for polarizing the microwaves in a single direction.

5. The system as claimed in claim 1 , further comprising:

a vacuum chamber connected to a lower portion of the refractor, the vacuum chamber including a substrate holder for holding a substrate to be etched.

6. The system as claimed in claim 1 , wherein the refractor has a different thickness between a central portion and a peripheral portion.

7. The system as claimed in claim 6 , wherein the refractor is thicker in the central portion than in the peripheral portion.

8. The system as claimed in claim 1 , wherein the refractor has a central portion and a peripheral portion, a distance between the microwave generator and the central portion being different than a distance between the microwave generator and the peripheral portion.

9. The system as claimed in claim 8 , wherein the central portion is closer to the microwave generator than the peripheral portion.

10. A plasma generation system for use with a substrate, comprising:

a microwave generator for generating microwaves;

an antenna for forming an electric field component of the microwaves having a non-planar wavefront;

a refractor for receiving the microwaves having the non-planar wavefront and for transmitting the microwaves as plane waves having a wavefront parallel to the substrate by refracting the microwaves; and

an electromagnetic unit for applying a magnetic field to plasma formed by the microwaves and for generating electron cyclotron resonance (ECR).

11. The system as claimed in claim 10 , wherein the refractor is a dielectric lens.

12. The system as claimed in claim 11 , wherein the dielectric lens is formed of alumina.

13. The system as claimed in claim 10 , wherein the antenna is a horn antenna having a width that gradually increases in a direction of propagation of the microwaves.

14. The system as claimed in claim 10 , wherein the microwave generator comprises:

a radio frequency power source for generating the microwaves;

a waveguide, which is connected to the radio frequency power source, for guiding the propagation of the microwaves; and

a polarizer, which is placed at an outlet of the waveguide, for polarizing the microwaves in a single direction.

15. The system as claimed in claim 10 , further comprising:

a vacuum chamber connected to a lower portion of the refractor, the vacuum chamber including a substrate holder for holding a substrate to be etched.

16. The system as claimed in claim 10 , wherein the refractor has a different thickness between a central portion and a peripheral portion.

17. The system as claimed in claim 16 , wherein the refractor is thicker in the central portion than in the peripheral portion.

18. The system as claimed in claim 10 , wherein the refractor has a central portion and a peripheral portion, a distance between the microwave generator and the central portions being different than a distance between the microwave generator and the peripheral portion.

19. The system as claimed in claim 18 , wherein the central portion is close to the microwave generator than the peripheral portion.

20. The system as claimed in claim 13 , wherein inner walls of the horn antenna are corrugated.