Optimization and characterization of RF MEMS inductors fabricated in PolyMUMPS technology

This work presents an analysis of a RF MEMS inductor of 3 square spirals fabricated with PolyMUMPS technology, the final device is shown. The structure was released using wet-etching post-process in 10% TMAH at 40°C in order to optimize performance as a result of the reduced parasitic losses. The software Sonnet® was used as simulation tool and its results showed that the Q factor of the inductor on the substrate is 28.09 at 5.6 GHz. The next step is to take into account some other simulations at different etching distances to identify the ideal etching that increases the Q factor, obtaining that the optimal etch distance is 200 ¿m under the metal. The experiments demonstrate that etch rate for silicon is about 0.05 ¿m/min and for polysilicon is less than 1% compared with silicon.