Integration of parallel-plate ferroelectric varactors with BCB-on-silicon microstrip circuits

A four mask process is developed to integrate parallel-plate ferroelectric varactors with BCB film microstrip circuits. A tri-layer stack, consisting of bottom electrode (M1), ferroelectric film and top electrode (M2), deposited on silicon substrate is used as a ground plane for microstrip circuits. A BCB film, spin coated on the tri-layer ground plane for microstrip circuits patterned in the third metal layer (M3). Simple circuits are fabricated to demonstrate the potential of the proposed integration.