Focused ion beam system for automated MEMS prototyping and processing

We have developed a focused ion beam (FIB) system for automated MEMS processing. This product, the Micrion MicroMill, has been successfully used in production and prototype milling of over three million thin film heads (TFH) used in hard disk drives. The FIB column consists of a liquid gallium (Ga+) ion source, running at 50 kV, producing beam currents up to 50nA. The milling rates achieved in the TFH application have been 0.5 - 4 um(3)/sec with spot sizes ranging from 150 - 800 nm. This tool is designed to easily integrate into current FAB facilities and supports a wide range of navigational requirements. Different milling scenarios can be easily created or modified using the integrated CAD-like design tools, allowing for quick production line design modifications or rapid prototyping of new designs. The milling strategy can ''adapt'' to dimensional changes caused by upstream process variations. On a real-time basis, the FIB system's pattern recognition / inspection software measures the individual part and precisely places the desired milling pattern. The flexible vector scan beam control can position the FIB, within sub-tenth micron dimensional control, to generate an endless variety of geometric milling patterns. This presentation will discuss the work currently done on inductive and magnetoresistive TFH devices as well as other potential MEMS processing applications.