MICROMACHINING WITH FOCUSED ION-BEAMS

Focused ion beam (FIB) systems are being increasingly used for many highly demanding fabrication applications in nanotechnology, yet so far little attention has been given to the associated problems of in situ metrology. Here, a FIB system is described which consists of an ion optical column, computer-controlled specimen stage, particle detector and image-processing hardware. The FIB column provides a minimum probe size of 250 nm at a variable working distance of 30-40 mm. The maximum field of view is 4 x 4 mm at a working distance of 40 mm. Beam current density is 100 mA cm-2. The instrument can be operated in micromachining mode for ultra-high precision material removal or in imaging mode for scanning ion microscopy. The use of FIB milling in microcircuit modification and repair, microsensor fabrication and other nanotechnology applications is described. Preliminary data are presented on the deposition of metal patterns with high spatial resolution.