Liquid metal ion sources for FIB microfabrication systems - recent advances

The liquid metal ion source (LMIS) has been largely reponsible for a significant growth in the level of activity in focused ion beam technology for microfabrication and materials analysis. Several embodiments of the basic blunt needle source are used, ranging from simple 'hairpin' devices to complex sources compatible with highly reactive liquid caesium. Most recently, alloy sources are being developed to produce beams of semiconductor dopant elements for direct selective area doping. Some recent experimental results are reviewed, including preliminary experiments using an alloy source of boron ions. The present state of theoretical understanding of the mechanisms of ion emission from the LMIS is also discussed. (orig.)