3D Double-Metal Capacitor Structure for High Capacitance Density

The patent transitions from conventional planar capacitor structures to three-dimensional capacitor structures by extending metal electrodes into via openings that penetrate through dielectric layers. This vertical extension into the third dimension significantly increases the effective surface area of the electrodes without increasing the planar footprint, thereby achieving higher capacitance while maintaining a compact form factor suitable for integrated circuits.

The patent implements a nested structure where first and second metal electrodes are positioned within via openings that extend through multiple dielectric layers. The electrodes are nested within the vertical stack of dielectric layers, with each electrode surrounded by dielectric material. This nested arrangement maximizes the use of vertical space and achieves high capacitance density within a compact three-dimensional structure.

The patent resolves this contradiction by moving the capacitance-generating structure from the planar dimension to the vertical dimension. By forming via openings that extend downward through dielectric layers and positioning electrodes within these vertical channels, the effective electrode surface area is dramatically increased without increasing the planar area occupied on the chip. This allows high-capacitance values to be achieved within a minimal chip footprint.

The patent utilizes a porous-like three-dimensional structure where via openings penetrate through dielectric layers, creating vertical channels that house the capacitor electrodes. This approach effectively increases the surface area available for capacitance formation by utilizing the vertical pore-like spaces within the dielectric stack, thereby achieving high capacitance without increasing the planar area occupied on the chip.

The patent segments the capacitor structure into multiple discrete components: first and second dielectric layers, first and second metal electrodes, and via openings. Rather than relying on a single thick dielectric layer, the total dielectric thickness is divided into multiple thinner layers that can be deposited and controlled with standard manufacturing precision. This segmentation allows each layer to be formed within achievable process tolerances while achieving the cumulative capacitance effect of the total dielectric thickness.

The patent changes the structural parameters of the capacitor by introducing vertical via openings and multi-layer electrode structures. Instead of simply increasing the thickness of a single dielectric layer (which would demand higher deposition precision), the patent modifies the geometry to include vertical extensions and multiple layers, thereby achieving higher capacitance through increased surface area and optimized electric field distribution rather than relying solely on increased dielectric thickness.