A barium zirconate titanate-based inorganic dielectric material with high permittivity as a lead-free insulator for semiconductor applications

BaZr x Ti 1 - x O 3 -Ba(Fe 0.5 Ta 0.5 )O 3 -FeTaO 4 (BZT-BFT-FT) ceramics were fabricated by a columbite route in an attempt to develop a lead-free inorganic dielectric material suitable for use as an insulating material with high relative permittivity and low dielectric loss for next-generation system-on-package (SOP) applications. The fabricated BZT ceramics with compositions of BaZr x Ti 1 - x O 3 with x = 0.05-0.30 all had a single-phase perovskite structure. The sample with 20/80 composition (100 x /(100-100 x ) in BaZr x Ti 1 - x O 3 ) exhibited the best dielectric properties with an ideal Curie temperature of 30 degrees C, high relative permittivity of 4750, and low dielectric loss of 0.6% at 1 MHz. The addition of BFT as a depressor agent and FT as a sintering aid, at optimal concentrations of y = 0.03 ((1- y )BZT- y BFT) and 0.5 mass% FT, yielded ceramics with epsilon r of 3080 and tan delta of 0.05% at 1 MHz. This novel lead-free inorganic dielectric material can therefore be expected to be useful as an inorganic insulating material with high permittivity for SOP applications.