Fabrication of SAW three phase unidirectional transducers using dielectric crossovers

Two common dielectrics used for isolation in semiconductor device fabrication, spin on glass (SOG) and polyimide, are evaluated for the fabrication of dielectric supported crossover interconnections for surface acoustic wave (SAW) devices employing three-phase unidirectional transducers (TPUDTs). An all-aluminium reliable fabrication process was developed using polyimide.