A laterally driven capacitive RF MEMS switch using parylene as dielectric layer

In this paper, we propose a novel laterally driven RF MEMS capacitive switch using parylene as insulation dielectric, taking advantages of low temperature deposition and conformal coating of parylene. The switch consists of three parts, including CPW line, switching plates and actuated structures which are composed of single crystalline silicon (SCS) bonded on the glass substrate. Two actuated structures and switching plates are located at both lateral sides of the RF signal line, which is coated with parylene. The preliminary measured results show that the parylene can completely overlay the sidewall of the signal line and switching plates. The switching time from the open to the close state is 105μs, while 15.6μs from the close to the open state. For the switch with 80nm-thick parylene, the measured isolation is 16.2dB at 20GHz when both sides are under close state. These results verify that the parylene is a possible candidate to act as sidewall dielectric to realize the lateral capacitive switch.