Optical singularity assisted method for accurate parameter detection of step-shaped nanostructure in coherent Fourier...

Area of Science:

• Semiconductor metrology
• Optical physics
• Nanotechnology

Background:

• Accurate measurement of nanostructure physical parameters is crucial for the semiconductor industry.
• Current optical far-field scattering methods face challenges in precise determination of dimensions like height and side-wall angle.

Purpose of the Study:

• To propose a novel metrology method for simultaneously determining the height and side-wall angle of step-shaped silicon nanostructures.
• To enhance the precision and robustness of nanostructure characterization using optical techniques.

Main Methods:

• Integration of an optical singular beam into a coherent Fourier scatterometry system.
• Analysis of the far-field scattering pattern's intensity profile.
• Utilizing the sensitivity of the singular beam to nanostructure parameter variations and adjusting the relative direction between the singularity and the structure.

Main Results:

• Simultaneous retrieval of height and side-wall angle of step-shaped silicon nanostructures.
• Demonstrated high precision in parameter determination due to the singular beam's sensitivity.
• The method proved to be robust and simple for micro- and nano-metrology applications.

Conclusions:

• The proposed optical metrology method offers a valuable and precise tool for characterizing silicon nanostructures.
• Singular beam scatterometry provides a significant advancement in semiconductor metrology.
• This technique can be widely applied in micro- and nano-fabrication process control and quality assurance.