Angular-Resolved Spectroscopic Lithography Characterization

The patent transitions from measuring one wavelength at a time (1D sequential measurement) to simultaneously measuring multiple wavelengths across a spectral range (2D parallel measurement in wavelength-space). This is achieved by implementing spectroscopic detection that captures the entire spectrum at once, rather than scanning through wavelengths sequentially, thereby maintaining precision while dramatically reducing acquisition time.

The patent combines multiple measurement functions into a single integrated system. By merging the wavelength selection function and detection function into a unified spectroscopic measurement approach, the system can simultaneously acquire data across multiple wavelengths in one measurement cycle, eliminating the time penalty of sequential measurements while preserving measurement accuracy.

The patent applies local quality by concentrating illumination precisely where needed - using a point source or focused beam that targets only the specific measurement location on the substrate. This eliminates wasted light from extended sources while maintaining sufficient illumination intensity at the measurement point, thereby improving both efficiency and measurement stability.

The patent extracts only the necessary portion of light from the source by using optical elements (such as condensers or focusing lenses) to concentrate illumination onto the specific target area. This removes the wasteful omnidirectional illumination characteristic of extended sources, directing light energy precisely where it is needed for measurement, thus improving stability without sacrificing intensity.

The patent implements continuous measurement capability by integrating scatterometry detection into the production exposure process itself. Rather than stopping production for separate measurements, the system continuously monitors substrate patterns during normal operation, enabling real-time error detection without interrupting the production flow, thus maintaining both measurement capability and high throughput.

The patent enables the production system to perform its own self-diagnosis and quality control by incorporating scatterometry measurement capability directly into the lithographic apparatus. The system uses its own exposure process to create test patterns and immediately measures them to detect errors, eliminating the need for separate external measurement equipment and procedures, thereby maintaining productivity while achieving comprehensive error detection.