In-Situ Wafer Film Thickness Measurement Using Equivalent Layer Spectra

The patent introduces an equivalent layer as an intermediary model to represent the complex dielectric environment. This equivalent layer with adjustable parameters serves as a mediator between the probe and the wafer film, allowing the system to account for spectrum deformation effects without requiring direct measurement through the deforming medium. The equivalent layer parameters are optimized to match the actual dielectric environment, enabling accurate thickness measurement despite the presence of slurry and other dielectrics.

The patent dynamically adjusts the parameters of the equivalent layer (such as refractive index and thickness) to match the actual measurement conditions. By changing these parameters based on the specific dielectric environment during CMP processing, the system maintains measurement precision across varying conditions while enabling real-time in-situ measurement.

The equivalent layer acts as an intermediary model that bridges the simple traditional spectrum model and the complex actual dielectric environment. Instead of directly modeling the complex slurry and interface structure, the equivalent layer provides a simplified yet accurate representation that can be integrated into standard spectrum models, maintaining model simplicity while improving measurement precision.

The patent enhances traditional spectrum models by introducing adjustable equivalent layer parameters. These parameters can be optimized to reflect the actual dielectric environment, allowing the model to accurately describe spectrum deformation without requiring complete reconstruction of the complex physical system. This approach maintains computational efficiency while improving accuracy.

The equivalent layer serves as a mediator that accounts for the complex CMP processing environment. By representing the slurry, interface layers, and other processing-specific dielectrics as an equivalent layer with optimized parameters, the system can perform reliable in-situ measurements during CMP processing without being directly affected by the complexity of the processing environment.

The patent adapts the equivalent layer parameters to match the specific CMP processing conditions. By dynamically adjusting these parameters during processing, the system maintains measurement reliability throughout the CMP process, enabling accurate real-time thickness monitoring that reflects the actual manufacturing conditions.