Thin Film Integral Capacitor Fabricated on a Polymer Dielectric for High Density Interconnect (HDI) Applications

Abstract

ABSTRACTThe expanding needs of mixed signal applications of thin film MCM technologies which combine analog, digital, power and opto-electric devices require a wide range of integral, thin film, passive components within the MCM structure. There is a need to incorporate these passive elements into the interconnect structure to reduce component count, decrease substrate area and to improve electrical performance. In this study, we investigated advanced material and processing technologies for the in situ formation of capacitor components during the fabrication of multilayer polymer/copper interconnect structures.Amorphous BaTiO3 film having a dielectric constant of 10 to 40 depending on stoichiometry was deposited on a surface roughness controlled metallized polyimide surface at room temperature using the reactive partial ionized beam (RPIB) technique. Simple metal/insulator/metal(MIM) capacitors were fabricated and characterized. Hundreds of pF capacitance with <10−6 Amp leakage current were obtained depending on the top metal electrode size, dielectric thickness, and stoichiometry of dielectric film. Annealing treatment on dielectric film significantly enhanced the leakage current property. After thermal cycling treatment, it was proved that thin film integral capacitor was reliable enough to be used as a practical MCM application. Process defects control was necessary to improve capacitor yield.