Chromatic aberration Ili-nits the current density which can be produced bv focused ion beam systems utilizing electrost@itic lenses. Studv of systems coi-nprising a liquid metal l'icid ionization source and an @ichronlatic quadrupole lens doublet offers the prospect of overcoming this limitation. Research objectives in Phase I include implementation ol' methods to compensate defects other than chromatic @iberrittioii, @ind the experimental deinonstr@ition or Lin achroiliatically l'ocused beaten with a diameter measured in najioiiieters. Research objectives of' Phase 11 include design @iiid construction of' achromatic lenses optimized for semiconductor applications, and their use in an experimental system with a probe size of' about 10 manometers and with high current densitv. Decreased feature size is an important goil in the I'abrica tion ol' integrated circuits. In @iddit'ion, ioii beam current densities higher than presently obtainable are required l'or niask-free, direct-write doping and especiiliv t'or lithography of very small circuit features. Accordinglv, the potential application of the research is to fabricatioii of' highly complex integrated circuits.The potential commercial application as described by the awardee: Small, high-current ion beams are expected to become of widespread future use in integrated circuit i-nanufacture. In Phase III the results of the proposed research may be transferred to the existing U.S. manufacturers of ion beam equipment, located nearby in suburban Boston.
