Gallium ION source and materials therefore
In one embodiment, a method for generating an ion beam having gallium ions includes providing at least a portion of a gallium compound target in a plasma chamber, the gallium compound target comprising gallium and at least one additional element. The method also includes initiating a plasma in the plasma chamber using at least one gaseous species and providing a source of gaseous etchant species to react with the gallium compound target to form a volatile gallium species.
1. A method for generating an ion beam having gallium ions, comprising:
providing at least a portion of a gallium fluoride target in a plasma chamber;
initiating a plasma in the plasma chamber using a non-fluorine-containing gas to generate inert gas ions;
generating, using the inert gas ions, a gaseous etchant to react with the gallium fluoride target to form the gallium ions,
wherein the generating the gaseous etchant species comprises generating a fluorine-containing etchant species by etching fluorine from the gallium fluoride target; and
generating a self-sustaining plasma using the fluorine-containing etchant species, wherein after initiation of the plasma a flow of the non-fluorine-containing gas into the plasma chamber is terminated.
2. The method of claim 1 further comprising providing the gallium fluoride target in an indirectly heated cathode source.
3. The method of claim 1 , wherein the gallium fluoride target has a melting temperature in excess of 800° C.
4. The method of claim 1 , wherein the gaseous etchant species is operable to generate a gas phase species having an ionization energy greater than 8 eV.
5. The method of claim 1 , wherein the fluorine-containing etchant species comprises GaF 2 .
6. An apparatus for generating gallium ions for a gallium ion beam, comprising:
a plasma source to generate a plasma within a plasma chamber, the plasma comprising inert gas ions formed from a non-fluorine-containing gas; and
a gallium fluoride target at least partially disposed in the plasma chamber,
wherein the inert gas ions and the gallium fluoride target interact to generate a gaseous etchant species operable to react with the gallium fluoride target to form the gallium ions,
wherein the gaseous etchant species is operative to generate ionized gaseous fluorine species in the plasma that originate from the gallium fluoride target, and
wherein the ionized gaseous fluorine species are operative to generate a self-sustaining plasma, wherein after initiation of the plasma a flow of the inert gas into the plasma chamber is terminated.
7. The apparatus of claim 6 , wherein the gallium fluoride target has a melting temperature in excess of 800° C.
8. The apparatus of claim 6 , wherein the plasma chamber comprises an indirectly heated cathode.
9. The apparatus of claim 6 , wherein the gaseous etchant species is operable to generate a gas phase species having an ionization energy greater than 8 eV.
10. The apparatus of claim 6 , wherein the fluorine-containing etchant species comprises GaF 2 .