Geometry-Dependent Quality Factors in ${\hbox{Ba}}_{0.5}{\hbox{Sr}}_{0.5}{\hbox{TiO}}_{3}$ Parallel-Plate Capacitors

Quality factor variation with top electrode area in thin-film barium-strontium-titanate parallel-plate capacitors is discussed. At low frequencies, the geometry dependence is consistent with the presence of a parallel parasitic loss pathway enabled by conduction over the device mesa surface. At high frequencies, the variation in the quality factor with top electrode area is due to a geometry-independent series resistance