Production of multicharged iron ions from solid and application to material processing

Abstract

Multiply charged ions of iron are produced from solid material in a 2.45 GHz electron cyclotron resonance (ECR) ion source. An ECR plasma is confined in the mirror field superimposed by the octupole magnetic field. Microwave of 2.45 GHz frequency is normally launched by using a rod antenna. The ECR zone is formed around the bottom of the magnetic mirror trap. The multicharged iron ions are produced by directly sputtering and evaporating the pure material in the ECR plasma. Argon gas is usually chosen for supporting gas, and the working pressure is about 10 -4~1 0 -3 Pa. The multicharged ions are extracted from the opposite side of mirror end against the target or the evaporator of the iron, and then multicharged ion beam is formed. Extraction voltage is normally 10 kV, the sector magnet separates mass/charge, and ion beams are collected by the Faraday cup. Multicharged iron ions up to Fe 8+ can be successfully extracted. The maximum ratio of total multicharged iron ions current to Ar ions current attains to about 15~17% in both methods. After improvement of ion extraction and beam transport, we try to form iron disilicides and to enhance photo-catalytic performance of titanium-dioxide thin films by applying the multicharged ion beams.