Modeling, design and analysis of the two movable plate nitride loaded MEMS variable capacitor

The modeling, design and analysis of the MEMS variable capacitor having two movable plates loaded with a Nitride layer is proposed. A trench in the silicon substrate underneath the capacitor is used to decrease the parasitic capacitance. The use of an insulation dielectric layer on the bottom plate of the MEMS capacitor prevents a short circuit and allows the top plate of nickel to relax on the nitride layer. The addition of the nitride layer results in increasing the capacitor's tuning range and eliminating the sticktion. Experimental, theoretical and analytical results are presented. The measured tuning range is found to be 280% at 1 GHz.