| abstract |
A method is provided for constructing well defined plated miniature metallic structures. A seedlayer may be formed over an insulative layer such as a gap layer of a write head. A protective layer, such as alumina or silicon dioxide, is formed on top of the seedlayer to protect it from a subsequent reactive ion etching (RIE) step. A relatively thick layer of material, such as polymeric photoresist, is formed on top of the protective layer, the thick layer being of a type of material which can be patterned by reactive ion etching. By photolithography, an RIE mask, such as a thin layer of patterned metal, is formed on top of the relatively thick resist layer. The pattern of the mask corresponds to the desired shape of the metallic structure to be formed by plating. After masking the relatively thick layer the relatively thick layer is anisotropically etched by RIE. After the thick layer is RIE'd the protective layer on top of the seedlayer portion to be plated is removed by an etchant such as an aqueous alkaline etchant containing EDTA. It is important that the polymeric photoresist not be attacked by this etchant since it would undercut the high definition required for the metallic structure. After the protective layer portion is removed electrodeposition takes place to plate the desired metallic structure on the seedlayer portion. After plating the remaining relatively thick layer can be removed by reactive ion etching and the remaining protective layer can be removed by the aforementioned etchant containing EDTA to leave the desired freestanding metallic structure with miniature high resolution features. |