GENERATION OF INTENSE PULSED ION BEAM AND ITS APPLICATION TO MATERIALS PROCESSING

摘要

Intense pulsed heavy ion beam is expected to be applied to materials processing including surface modification and the ion implantation. For those applications, it is very important to generate high-purity ion beams with various ion species. A magnetically insulated ion diode with an active ion source of a vacuum arc plasma gun has been developed in order to generate pulsed metallic ion beams. When the ion diode was operated at diode voltage 200 kV, diode currents 15 kA and pulse duration 100 ns, the ion beam with an ion current density of > 200 A/cm~2 was obtained at 50 mm downstream from the anode. From Thomson parabola spectrometer measurement, the ion beam consists of aluminum ions (Al~+, Al~(2+) and Al~(3+)) of energy 140-780 keV and the proton impurities of energy 170-190 keV. To evaluate the irradiation effect of the ion beam, an amorphous silicon thin film of thickness ≈ 1μm was used as the target, which was deposited on the glass substrate. By the X-ray diffraction measurement of the films before and after the irradiation, the film was found to be poly-crystallized after 5-shots of the pulsed aluminum ion beam irradiation.