Patent Number: 
Section: claims

1. A beam line system of an ion implanter, the beam line system comprising:a hollow tube having an inlet and an outlet, wherein the hollow tube is a collimator tube, an ion beam emitted by the ion implanter is introduced into the hollow tube through the inlet and exited from the hollow tube through the outlet; anda plurality of protruding structures formed on an inner wall of the hollow tube, wherein each of the protruding structures has a reflective surface for reflecting a portion of the ion beam. 2. The beam line system according to claim 1, wherein the hollow tube is made of graphite. 3. The beam line system according to claim 1, wherein the protruding structures are contiguous wedge-shaped structures on the inner wall of the hollow tube. 4. The beam line system according to claim 1, wherein the reflective surface of the protruding structure is substantially vertical to a traveling direction of the ion beam. 5. The beam line system according to claim 1, wherein a ratio of a height of the reflective surface of the protruding structure to a length of the protruding structure along a traveling direction of the ion beam is about 1:5. 6. The beam line system according to claim 1, wherein the portion of the ion beam which is not reflected by the protruding structures is exited from the outlet of the hollow tube. 7. The beam line system according to claim 6, wherein an end analyzer is positioned at a terminal of the beam line system to detect the portion of the ion beam which is exited from the outlet of the hollow tube. 8. The beam line system according to claim 7, wherein the end analyzer is a Faraday cup detector. 9. An ion implantation process, which is implemented by the beam line system according to claim 1. 10. An ion implanter, comprising:an ion source for producing ions;an analyzing magnet for producing an ion beam by selecting desired types of ions; anda beam line system for transmitting the ion beam, wherein the beam line system comprises a hollow tube with an inlet and an outlet and a plurality of protruding structures formed on an inner wall of the hollow tube, wherein the hollow tube is a collimator tube, the ion beam is introduced into the hollow tube through the inlet and exited from the hollow tube through the outlet, wherein each of the protruding structures has a reflective surface for reflecting a portion of the ion beam. 11. The ion implanter according to claim 10, further comprising:an accelerating system for accelerating the ion beam;a focusing system for focusing the accelerated ion beam; anda target chamber for receiving the ion beam from the focusing system. 12. The ion implanter according to claim 10, wherein the hollow tube is made of graphite. 13. The ion implanter according to claim 10, wherein the protruding structures are contiguous wedge-shaped structures on the inner wall of the hollow tube. 14. The ion implanter according to claim 10, wherein the reflective surface of the protruding structure is substantially vertical to a traveling direction of the ion beam. 15. The ion implanter according to claim 10, wherein a ratio of a height of the reflective surface of the protruding structure to a length of the protruding structure along a traveling direction of the ion beam is about 1:5. 16. The ion implanter according to claim 10, wherein the portion of the ion beam which is not reflected by the protruding structures is exited from the outlet of the hollow tube. 17. The ion implanter according to claim 16, wherein an end analyzer is positioned at a terminal of the beam line system to detect the portion of the ion beam which is exited from the outlet of the hollow tube. 18. The ion implanter according to claim 17, wherein the end analyzer is a Faraday cup detector.