A BARIUM ZIRCONATE TITANATE-BASED INORGANIC DIELECTRIC MATERIAL WITH HIGH PERMITTIVITY AS A LEAD-FREE INSULATOR FOR SEMICONDUCTOR APPLICATIONS

ABSTRACT

BaZr _x Ti_1−x O₃-Ba(Fe_0.5Ta_0.5)O₃-FeTaO₄(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 O₃ with x = 0.05–0.30 all had a single-phase perovskite structure. The sample with 20/80 composition (100x /(100–100x)) in BaZr( _x Ti_1−x O₃) exhibited the best dielectric properties with an ideal Curie temperature of 30°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-yBFT) and 0.5 mass% FT, yielded ceramics with ϵ_r of 3080 and tanδ 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.

Keywords:

• Lead-free inorganic dielectric material
• system-on-package
• depressor
• relative permittivity
• dielectric loss
• BZT-BFT-FT

ACKNOWLEDGMENT

This work was partly supported by the Fundamental Technology Research Promotion Project in 1901 from the New Energy and Industrial Technology Development Organization (NEDO) of Japan.