Low-temperature high-k dielectrics for embedded microcircuit systems

This work is intended to provide examples of low-temperature dielectrics applicable for embedded microcircuit systems, which can be characterized by different dielectric constants (k) of k ∼ 8.2, k ∼ 48.2 and k ∼ 1337. The first two dielectrics contain crystallizable glasses as a major component, while the dielectric of k ∼ 1337 is based on BaTiO₃ with a small proportion of uncrystallizable bismuth silicate glass. The physical and dielectric properties of the three dielectrics were evaluated, as excellent dielectric performance was demonstrated. Specifically, the shrinkage issue was addressed as an example in the case of hetero-lamination structures containing a higher-k dielectric as an embedded capacitor. It was concluded that the overall dimensional changes depended on the firing behavior, i.e., densification and crystallization, of the individual dielectric tape layer. Lower shrinkage of 2.4 to 5.4 % was observed for the embedded laminate systems, which was unexpected from the shrinkage values (16.4 % for the k ∼ 8.2 dielectric and 14.1 % for the k ∼ 48.2 dielectric) of each constituent dielectric layer.