High capacitance density thin film integrated tantalum pentoxide decoupling capacitors

The process development and analysis of a multilayered thin film integrated capacitor is presented. Thin film integrated capacitors show great promise as IC power supply decoupling capacitors. Their low intrinsic inductance allows them to deliver fast switching high currents to the IC. However, current thin film capacitors are limited in capacitance due to the limitation of substrate area in boards or packages. Generally, there is not enough area available to produce the capacitance needed so that integrated capacitors can completely replace discretes. In this paper a multilayer thin film integrated capacitor design was discussed. The details of the multilayer process was described, as well as process challenges and preliminary results of the research. Currently capacitance densities in the range of 0.4 μP/cm² have been obtained with a two layer process.