Miniature electron microscopes for lithography

Two inexpensive and extremely accurate methods for fabricating miniature 10 - 50 kV and 0.5 - 10 kV electron beam columns have been developed: `slicing,' and `stacking.' Two or three miniature columns could be used to perform a 20 nm or better alignment of an x-ray mask to a substrate. An array of miniature columns could be used for rapid wafer inspection and high throughput electron beam lithography. The column fabrication methods combine the precision of semiconductor processing and fiber optic technologies to create macroscopic structures consisting of charged particle sources, deflecting and focusing electrodes, and detectors. The overall performance of the miniature column also depends on the emission characteristics of the micromachined electron source which is currently being investigated.