Generation of the large current cluster ion beam

Abstract

High ion dose is needed to realize the nano-level smoothing and etching of hard materials with increasing the productivity of processing using cluster ion beam. In order to achieve large current cluster ion beam, the cluster generation, ionization and ion transportation were studied. The intensity of neutral cluster beam increased with source gas pressure. The efficient ionization and extraction were realized by structural improvement of the ionizer. As a result, when the gas pressure was 15,000 Torr and the electron emission current is 300 mA, the beam current reached 500 μA. The size distributions of large current Ar cluster ion beam were measured using time-of-flight method. The distributions prove that the neutral beams include clusters with the size up to 160,000 atoms and that the distributions can be controlled by the source gas pressure and ionization condition.