3-D lithography and metal surface micromachining for RF and microwave MEMS

A new metal surface micromachining technology utilizing 3-D lithography, electroplating, and mechanical polishing has been developed to fabricate arbitrary 3-D metal microstructures as post-IC processes at low temperature below 120/spl deg/C. Using this technology, various highly-suspended 3-D microstructures have been successfully demonstrated for RF and microwave MEMS applications. We have fabricated spiral inductors suspended 100 /spl mu/m over the substrate, coplanar waveguides suspended 50 /spl mu/m over the substrate, and complicated micro-coaxial lines which have 50 /spl mu/m-suspended center signal lines surrounded by ground shields of 100 /spl mu/m in height.