Microwave micromachined structures on < 100 > silicon substrate using polyimide-supported pads

The aim of this paper is to present the manufacturing of micromachined micr owave circuits structures on low resistivity silicon substrate using a poly imide insertion layer. The structures are supported on 1.5-mu m thin dielec tric membranes. The parasitic capacitances existing at the metallic contact s/silicon ground interface, are avoided by creating a 20-30-mu m thick poly imide layer between the CrAu metallization and the silicon substrate, in th e pads zones. The preliminary microwave measurements of these structures pr esent similar characteristics with the structures realized on high resistiv ity silicon wafers. (C) 2000 Elsevier Science B.V. All rights reserved.