Reconstruction of a complex profile shape by weighting basic characterization results for nanometrology

Area of Science:

• Nanotechnology
• Optical Metrology
• Materials Science

Background:

• Scatterometry is a key nondestructive technique for nanostructure characterization.
• It involves analyzing diffracted light to reconstruct periodic structure profiles.
• Current methods often require a predefined geometrical profile shape.

Purpose of the Study:

• To propose and demonstrate a new scatterometry method for reconstructing any geometrical profile shape.
• To enable detection of incorrect profile shapes in lithography or etching processes.
• To validate a weighting profile approach for enhanced nanostructure characterization.

Main Methods:

• Developed a weighting profile approach combining multiple basic characterization results.
• Applied the method to theoretical samples for feasibility demonstration.
• Compared the novel method against a classical scatterometry approach using a generic profile.

Main Results:

• The weighting profile method successfully reconstructed various geometrical shapes, including those not in the initial model.
• Demonstrated feasibility for identifying incorrect profile shapes in simulated fabrication scenarios.
• Showcased the method's potential to overcome limitations of traditional scatterometry.

Conclusions:

• The weighting profile approach offers a versatile solution for nanostructure profile reconstruction.
• This method enhances the capability of scatterometry for process control and defect detection.
• The technique is robust and applicable to a wider range of geometrical profiles than conventional methods.