Isolation Capacitor Edge Ring Using High-k Dielectric

The patent applies local quality by placing a ring structure made of high dielectric constant material (such as silicon nitride) specifically at the locations of peak electric fields around the edges of the capacitor plates. This localized modification allows the high-k material to mitigate the harmful peak fields where they occur most intensely, while the rest of the insulating layer can maintain its original SiO2 composition and properties.

The patent employs composite materials by combining silicon dioxide (low-k material) with a high dielectric constant material (such as silicon nitride) in a structured configuration. The composite structure consists of the SiO2 insulating layer with a ring structure of high-k material positioned at strategic locations, creating a composite dielectric system that leverages the breakdown strength of SiO2 while using the high-k material to control peak field regions.

Instead of uniformly increasing the dielectric layer thickness throughout the entire capacitor structure, the patent applies local quality by concentrating the high dielectric constant material in a ring structure at the critical peak field regions. This localized approach allows the capacitor to withstand high voltages without requiring a proportional increase in overall dielectric thickness, thereby maintaining compact capacitor dimensions.

The patent changes the dielectric parameter (dielectric constant) locally by introducing high-k material in the ring structure, rather than changing the physical thickness parameter uniformly across the entire dielectric layer. This parameter change approach allows the capacitor to achieve higher voltage withstand capability through increased dielectric constant in critical regions, avoiding the need to increase overall capacitor size.