Stacked Decoupling Capacitors in Substrate for Low Inductance

The patent extends the decoupling capacitor structure into the vertical dimension by creating stacked capacitors that occupy multiple layers of the substrate. The first capacitor is formed in a first region and the second capacitor is formed in a second region above the first region, allowing both capacitors to be electrically connected in parallel while occupying minimal planar area. This three-dimensional arrangement provides sufficient decoupling capacitance without consuming excessive substrate area.

The patent implements nested capacitor structures where the second capacitor is positioned above and overlaps with the first capacitor in the vertical dimension. The electrodes and dielectric layers are arranged such that the second capacitor is effectively nested within the vertical space occupied by the first capacitor, maximizing space utilization and providing high capacitance density.

The patent resolves this contradiction by moving the decoupling capacitor implementation from a two-dimensional planar arrangement to a three-dimensional stacked arrangement. Multiple capacitor layers are formed vertically, allowing high capacitance values to be achieved without increasing planar footprint. This enables continued transistor miniaturization while maintaining adequate decoupling capacitance.

The patent combines multiple capacitor structures into a unified stacked decoupling system where the first and second capacitors are electrically connected in parallel. This merged structure provides the total decoupling capacitance required while occupying minimal substrate area, allowing maximum space for high-density transistor implementation.

The patent places decoupling capacitors in close proximity to the IC power supply pins, effectively pre-positioning charge reservoirs where they are most needed. These capacitors provide immediate charge during transient conditions, compensating for the longer response time of the remote voltage regulator and maintaining power supply stability despite the increased distance.

The stacked decoupling capacitors act as intermediary elements between the remote voltage regulator and the IC. They provide a local charge reservoir that mediates the power supply connection, allowing the voltage regulator to be placed flexibly in the layout while the capacitors ensure stable power delivery to the IC by providing instantaneous charge during transients.