Generation of an intense pulsed aluminum ion beam by a magnetically insulated diode with vacuum arc ion source

Abstract

A magnetically insulated ion diode with an active ion source of a gas puff plasma gun has been developed in order to generate a high-intensity pulsed heavy ion beam for the implantation process of semiconductors and the surface modification of materials. When the ion diode was operated at diode voltage ≈190 kV, diode current ≈15 kA and pulse duration ≈100 ns, the ion beam with an ion current density of 54 A/cm2 was obtained at 50 mm downstream from the anode. It was found from the evaluation of ion species and energy of the ion beam by a Thomson parabola spectrometer (TPS) that N+ and N2+ beams of 100–300 keV energy were accelerated with proton impurities of 90–190 keV energy. The purity of the nitrogen ion beam was estimated to be 94 %. In addition, to produce the pulsed metallic ion beam we developed the B y type ion diode using a vacuum arc plasma gun instead of the gas puff plasma gun. The aluminum ion beam with an ion current density of 53 A/cm2 was obtained at 50 mm downstream from the anode. We found from TPS measurement that the ion beam consisted of the Al2+ and Al3+ beams with the energy of 100–300 keV and the proton impurities with the energy of 110–170 keV. The purity of the aluminum ion beam was estimated to be 92.4 %.