Charge neutralizing device
Disclosed is a charge neutralizing device which is capable of being applied to a substrate 13 having a large area and in which electrons having low energy of 5 eV or less, and preferably 2 eV, are supplied so that charge due to ion implantation and damage by the electrons are avoided with respect to a cusp device. The charge neutralizing device includes a microwave generating unit, a plasma generating unit that generates electron plasma using a microwave generated from the microwave generating unit, and a contact unit that brings the electron plasma generated from the plasma generating unit into contact with a beam plasma region including an ion beam.
1. A charge neutralizing device, comprising:
a microwave generating unit;
a plasma generating unit that generates an electron plasma by using a microwave generated from the microwave generating unit; and
a contact unit that brings the electron plasma generated from the plasma generating unit into contact with a beam plasma region including an ion beam through a plasma tube which surrounds the ion beam.
2. The charge neutralizing device according to claim 1 , wherein the plasma tube surrounds the ion beam in a ring shape.
3. The charge neutralizing device according to claim 1 , wherein the contact unit includes a plasma tube which is disposed so as to surround the ion beam or a scan region so that the plasma tube corresponds to a shape of the ion beam or the scan region of the ion beam.
4. The charge neutralizing device according to claim 2 , wherein the plasma generating unit includes a waveguide disposed so as to surround an external surface of the plasma tube, and the microwave is transferred from the microwave generating unit through the waveguide to the plasma tube while gas is supplied into the plasma tube, thereby generating the plasma in the plasma tube.
5. The charge neutralizing device according to claim 1 , wherein the plasma generating unit includes a coaxial cable.
6. The charge neutralizing device according to claim 2 , wherein the waveguide is arranged in parallel with the plasma tube to come into contact with a conductive tube which is a path through which the ion beam passes.
7. The charge neutralizing device according to claim 4 , wherein the gas is an inert gas.
8. The charge neutralizing device according to claim 4 , wherein at least one slit is provided between the plasma tube and the waveguide at a predetermined position.
9. The charge neutralizing device according to claim 8 , wherein a plurality of slits are provided between the plasma tube and the waveguide at predetermined positions.
10. The charge neutralizing device according to claim 2 , wherein an opening is formed in a side of the plasma tube that is close to the ion beam.
11. The charge neutralizing device according to claim 2 , wherein a plurality of openings are formed in the side of the plasma tube that is close to the ion beam.
12. The charge neutralizing device according to claim 2 , wherein the waveguide is disposed so as to surround the ion beam at a side thereof at which a transmission direction of the microwave in the waveguide is perpendicular to a flow direction of the ion beam.
13. The charge neutralizing device according to claim 12 , wherein the waveguide has a structure where the gas is supplied into the plasma tube so that the gas flows from a downstream to an upstream in the transmission direction of the microwave in the waveguide.
14. The charge neutralizing device according to claim 1 , wherein the plasma is generated by the excitement of the microwave so as to supply the electrons to the beam plasma including the ion beam.
15. The charge neutralizing device according to claim 1 , wherein the plasma is generated by the excitement of the microwave so as to supply the electrons to at least one portion among portions in the vicinity of the solid base to which the ion beam is radiated.
16. The charge neutralizing device according to claim 1 , wherein the plasma is maintained at low temperatures by the excitement of the microwave so as to supply the electrons having low energy of 2 eV or less.
17. The charge neutralizing device according to claim 4 , wherein the microwave generating unit is structured so that a stationary wave of the microwave is generated in the waveguide.
18. The charge neutralizing device according to claim 6 , wherein the microwave generating unit is structured so that a progressive wave of the microwave is generated in the waveguide.
19. An ion implanting device comprising the charge neutralizing device according to claim 1 .
20. A beam line device comprising the charge neutralizing device according to claim 1 .
21. A semiconductor device that has an internal voltage of 1 V or less and is formed by performing ion implantation using the charge neutralizing device according to claim 1 .
22. An object having an ion implantation region, that is formed by performing ion implantation using the charge neutralizing device according to claim 1 .