Metal contact capacitive switch on low-resistivity silicon wafer

This paper describes a DC contact capacitive shunt switch fabricated on low-resistivity silicon substrate. In this switch, the dielectric layer is shifted onto the ground planes of the coplanar waveguide (CPW). The contact between the metal bridge and the center conductor becomes a DC contact when the metal bridge is driven down. The down-state capacitance degradation problem is solved. The switch is fabricated on a low-resistivity silicon substrate. This is the first time where an RF MEMS switch can be fabricated on a low-resistivity silicon substrate without any wafer transfer technology. Measurement results show that the insertion loss is lower than 0.4 dB up to 26.5 GHz and the isolation is 15 dB at 1 GHz, 26 dB at 10 GHz and 27 dB at 26.5 GHz. The down/up states capacitance ratio is 1000.