Development of boron liquid–metal–ion source

Abstract

A boron liquid–metal–ion source is described that uses a combination of a glassy carbon or carbide emitter and a Ni–B base alloy as its source material. The B+ ion emission current is 25%–35% of the total emission current, and the energy spread for B+ ions is 12 eV at a total current of 30 μA. A source lifetime of more than 250 h was achieved with a total current of 30–50 μA. This source mounted on a mass-separated focusing column has led to B+ submicron beams with maximum energies of 20 keV for preliminary experiments on maskless implantation.