Microcolumns
The ongoing miniaturization of structures on microprocessors and other electronic devices demands for new production methods. Electron beam lithography is a technique used already to produce structures in the order of a few nanometers at moderate cost. The desired structures are written directly on a substrate by an electron beam generated in an evacuated column. The beam is guided in the column by electron optical elements and moved over the substrate to be structured in the desired manner by the use of deflectors. Industrial application of this method is limited by the relatively long writing time prohibiting efficient high volume fabrication. To reduce the production time, it is desirable to miniaturize the columns and to operate many such microcolumns in parallel for writing the structures. Such arrays of microcolumns fitted with detectors can also be used for inspection purposes during fabrication processes. The individual components of microcolumns are of sizes where MEMS processes are employed for fabrication. Within this scope, our group in collaboration with other research institutes and industrial partners is working on
To further improve the performance of microcolumns, electron sources with an extremely high brightness, low energy width, small source size and high emission stability are necessary. So far the required specifications could not be reached by conventional electron emitters, like field emitters from tungsten tips. Furthermore, the fabrication process should allow for the efficient fabrication of electron sources for microcolumns. Our group investigates the use of carbon nanotubes (CNTs) as field emitters. The CNTs are fabricated by chemical vapor deposition (CVD) on a pre-structured substrate and tested with respect to their emission properties.
Left: Schematic concept of a microcolumn
Left: SEM image of two octupole deflectors References: |
