Scatterometry-based metrology with feature region signatures matching

Area of Science:

• Optical physics
• Materials science
• Nanotechnology

Background:

• Scatterometry is a sensitive technique for monitoring lithographic processes.
• Optical diffraction from periodic structures provides valuable information about nanoscale features.
• Accurate and efficient extraction of structural parameters is crucial for process control.

Purpose of the Study:

• To develop an efficient algorithm for extracting grating structure parameters from scatterometry data.
• To improve the speed and accuracy of lithographic process monitoring.
• To reduce the computational resources required for analyzing diffraction data.

Main Methods:

• A feature region measurement algorithm was developed.
• The algorithm identifies angles with maximal information content for surface relief profile determination.
• A library data matching process was employed to determine grating structure.

Main Results:

• The feature region algorithm accurately and quickly extracts constitutive parameters from diffraction data.
• The method efficiently determines grating structure by selecting informative reflectance angles.
• Significant reductions in the number of measurements and signature matching library size were achieved.

Conclusions:

• The developed feature region algorithm enhances the efficiency of scatterometry for lithographic process monitoring.
• This method offers a faster and more resource-efficient approach to nanoscale metrology.
• The algorithm's ability to reduce data requirements makes it suitable for high-throughput industrial applications.