Fabrication of high depth-to-width aspect ratio microstructures

It is reported that a 3-D fabrication process, based on sputtering of a thin-film plating base, on conventional UV lithography, and on electrochemical deposition of gold, makes microstructures of considerable height and resolution possible. The thin-film formation and the lithographic process are outlined, particular attention being paid to layer deposition and structure printing. The present resolution limit is about 4.5 mu m for a 30- mu m-thick resist. Much thicker layers (80 mu m) can be printed with reduced resolution. The results are discussed and process characteristics relevant in various applications are considered.<
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