Wide band frequency and in situ characterisation of high permittivity insulators (High-K) for H.F. integrated passives

High permittivity insulators (High-K) are progressively introduced in high-speed integrated passives and devices in order to optimize circuits performances. However, High-K properties are expected to vary with manufacturing process and also frequency as relaxation and resonance mechanisms occur. It is necessary to analyze and evaluate High-K behaviour from DC to microwave frequency. Real permittivity (K or ε′r) and losses (ε″r) assessment is required over a wide band of frequency to select the most suitable insulator. The proposed method enables the characterization of as deposited thin (down to 60 nm) planar dielectrics integrated below a copper coplanar wave-guide up to 40 GHz. Results of Si3N4, Ta2O5 and STO insulators are presented in this paper.