Electrothermally actuated RF MEMS capacitive switch with atomic layer deposited (ALD) dielectrics

In this paper, we developed an electrothermally driven RF MEMS capacitive switch, where the HfO₂ film, deposited by atomic layer deposition (ALD) process, was used as insulation dielectric of the capacitor formed by the signal line and switching plate. Thanks high permittivity and excellent electrical and thermal isolation properties of the HfO₂ film, as well as high driving force of the electrothermal actuator, the single side isolation of the proposed switch with HfO₂ film was up to 17dB at 20GHz. The results demonstrate that the HfO₂ film is a good candidate material acting as sidewall dielectric to realize the lateral capacitive switch.