Development of boron and phosphorus liquid metal ion sources for the focused ion beam system

The approach taken here was to develop and build dual carbon filament liquid metal ion sources along with the test bed system. Pd73B27 and Pt58B42 binary alloys were selected as p-type dopant sources, and Cu3P binary alloy was used as n-type dopant source. Three emitters with different tip radii were used in the present investigation. The results indicate that Pd73B27 alloy is a good candidate for a boron liquid metal ion source. This conclusion was derived in this investigation from a lifetime test result with 2.5 μm emitter of more than 120 hours. Pt58B42 alloy is not a suitable alloy source for a boron liquid metal ion source despite the higher mole fraction of boron to be used as a source of ionizing species. Cu3P alloy is a good candidate for a phosphorus liquid metal ion source. Any apparent chemical interactions were found by metallographic technique, although AES result shows emitter element in the spectrum of collected beam current. A combination of rhenium and graphite ribbon as liquid metal ion source emitter and heater used in this investigation is the only possible approach to produce a long lifetime boron and phosphorus liquid metal ion source