Methodology for evaluating the information distribution in small angle scattering from periodic nanostructures

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Manufacturing

Background:

• Advanced semiconductor manufacturing requires metrology for sub-10 nm features.
• Traditional optical methods are insufficient for characterizing nanoscale structures.
• Critical Dimension Small Angle X-ray Scattering (CDSAXS) offers nanostructure characterization but requires optimization.

Purpose of the Study:

• To develop guidelines for optimizing CDSAXS angle selection.
• To reduce measurement time and improve feasibility for fabrication settings.
• To minimize uncertainty in nanostructure shape determination.

Main Methods:

• Conducted simulation studies on various nanostructures.
• Analyzed subsets of the full angular range (0-60 degrees).
• Evaluated the impact of angle combinations on shape uncertainty.

Main Results:

• Low angles (<3 degrees) are crucial for minimizing line-width uncertainty.
• Higher angles near high curvature regions best constrain structure height.
• Optimal uncertainty reduction is generally achieved using combinations of angles.

Conclusions:

• Simulation-guided angle selection can significantly reduce CDSAXS measurement time.
• Guidelines for angle selection enable efficient nanostructure characterization.
• This approach enhances the applicability of CDSAXS in semiconductor fabrication.