In this work we develop surface-micromachined RF MEMS switches in III–V technology making use of materials which can be alternative to the ones commonly used. In this way, some technological constraints concerning RF MEMS reliability can be overcome. Specifically, we evaluate the potential of tantalum nitride (TaN) and tantalum pentoxide (Ta 2 O 5 ) to be used for the switches actuation pads and dielectric layers, respectively. To this scope, a compositional, structural and electrical characterization of TaN and Ta 2 O 5 films as a function of the deposition parameters (temperature, sputtering mixture composition, and film thickness) is performed. Both shunt and series switches are prepared and show good switching capabilities by a preliminary analysis. The complete device characterization is in progress and will be presented.