| RF MEMS switches have an advantage over PIN diodes and MESFETs in isolation, insertion loss, linearity, power dissipation and can be used in broader frequency band. RF MEMS switches can be used to make phase shifter, filter, switch array, etc. The main application areas of MEMS switches are radar systems, satellite communication systems and wireless communication systems. The fabrication processes of metal-metal contact RF MEMS switch and the test of its DC property are the main content of this thesis.Metal-metal contact switch includes electrode, waveguide, contact,sacrificial layer and suspended beam.We study the fabrication processes and optimize the process parameters and succeed in making the switch. We test the pull-down voltage of the switch and its height change between down and up state. The fabrication processes of metal-metal contact switch include the following steps. Electrode, waveguide and contact are made through lift-off process. Sacrificial layer is made through rotational spread. The structure of suspended beam is made through PECVD process. The moving parts are released by selectively etching an underlying sacrificial layer through ICP dry etching and oxygen plasma etching.We succeed in depositing and lifting-off gold of 2 micrometer in thickness, plasma enhanced vapor depositing silicon nitride on polymide of 1 micrometer in thickness and releasing the suspended beam. We test the height of silicon nitride suspended beam from different depositing condition in laser-scanning microscope and decide the most proper depositing condition for RF MEMS switch.we research the on and off state of the switch, observe the pull-down property of the assembled sample in microscope and test its pull-down height when applied DC voltage. The pull-down voltage of the switch is from 22 volt to 27volt. The metal contact cannot touch the down electrode when the switch is applied DC voltage due to the residual stress in the thin film, so the signal cannot transmit.
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