Minuscular sculpturing

Abstract: Most of the processes employed in microstructure technology have been adopted from the fabrication scheme of integrated circuits (IC). Although being extremely reliable and cost efficient, they suffer from poor material and geometrical flexibility. In addition their spreading is hampered by the need for expensive equipment and certain environmental conditions. In the rapidly expanding field of microelectromechanical systems there is a need for truly three dimensional structures, not feasible by planar IC processes, as well as a wish to use and integrate materials with properties other than those of semiconductors and thin metal films. This treatise deals with recent and completely new process technologies with a potential of bridging the gap between needs and tools in this field, and relates them to conventional microprocessing.Methods to superimpose, or even induce, a virtual wet etch anisotropy in almost any insulating material by swift heavy ions have been developed. By this, microstructures of arbitrary lateral geometry and inclination have been realised in amorphous materials, like polymers and glasses, as well as in highly ordered materials like quartz.Two techniques to minutely structure conductive materials have been studied. The subtractive electro-discharge machining was successfully combined with wet etching to improve the surface finish and remove the relatively thick heat affected surface layer of micromechanical elements. With the additive localised electrodeposition relying on the free and direct writing of metal structures in an electrolyte with the help of a microelectrode, resolution and surface finish were improved by adding a complexing agent and supporting electrolyte.Finally, a method to build structures drop-by-drop from dispersed solutions with particles ejected by a micromachined jet nozzle was developed, and applied to a ceramic slurry of lead zirconate titanate - a piezoelectric ceramic.

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