A new flexible scatterometer for critical dimension metrology

Area of Science:

• Metrology
• Optics
• Nanotechnology

Background:

• Characterizing nanostructured surfaces is crucial for advanced photolithography.
• Existing metrology techniques face limitations in precision and versatility.

Purpose of the Study:

• To develop and present a novel deep ultraviolet (DUV) scatterometer system.
• To enable versatile measurements including scatterometry, ellipsometry, and reflectometry.
• To characterize critical dimension (CD), pitch, and edge profiles of nanostructures.

Main Methods:

• Development and setup of a new DUV scatterometer at the National Metrology Institute of Germany.
• Implementation of a variable system concept allowing multiple measurement modes.
• Utilizing operation wavelengths from 840 nm to 193 nm for at-wavelength metrology.

Main Results:

• The system demonstrates high versatility for various metrology tasks.
• It enables precise characterization of linewidth/critical dimension (CD), grating period (pitch), and edge profiles.
• Adaptable measurement parameters optimize sensitivity and unambiguity for specific problems.

Conclusions:

• The developed DUV scatterometer offers a powerful and adaptable solution for nanostructure metrology.
• It supports state-of-the-art photolithography by providing critical dimensional and profile data.
• Future applications include advanced metrology for next-generation lithographic processes.