Electrostatic Chuck Dielectric Tuning for Wafer Etch Uniformity

The patent applies local quality by creating spatially varying dielectric properties within the electrostatic chuck structure. Specifically, the dielectric layer has different dielectric constants in different radial zones (higher at the center, lower at the edges), which locally modifies the RF coupling strength. This allows the single-fed system to achieve differential RF power delivery across the wafer surface, enabling tunable etch rates from center to edge without requiring the complexity of a dual-fed architecture.

The patent employs parameter changes by modifying the dielectric constant parameter of the dielectric layer in the electrostatic chuck. By varying the dielectric constant spatially (higher at center, lower at edges) and potentially temporally (adjustable during processing), the system achieves tunable RF coupling and controllable etch rates. This approach replaces the need for expensive dual RF feed hardware with a simpler, more cost-effective material property modification.

The patent resolves this contradiction by implementing local quality through spatially varying dielectric properties in the electrostatic chuck. The dielectric layer is engineered with different dielectric constants in different zones (higher at center, lower at edges), which compensates for the non-uniform RF field distribution from a single feed. This local property variation enables the simple single-fed system to achieve uniform and tunable etch rates across the wafer surface.