A sealed-cone-type liquid metal ion source (LMIS) suitable for lithium has
been designed. It consists of a conical metal reservoir. a ceramic lid atop
the reservoir covering the ion material, a tungsten filament, and a tungst
en-needle emitter. The sealed-cone-type LMIS has good efficiency in heating
and any contamination of the ion source due to the deposition of the sourc
e material is minimal. The chemical reaction of Li2CrO4 with Si was used to
produce the Li liquid metal ion because it does so more easily than the he
ating of the Li metal does. The use of the Li primary ion in the secondary
ion mass spectrometry (SIMS) analysis increased the yield of negative ions,
which is similar to the case of the Cs primary ion. The use of light lithi
um ions improves beam focusing, which in turn increases the sensitivity of
element analysis and ion imaging of a microarea.