Reflective Small Angle Electron Scattering to Characterize Nanostructures on Opaque Substrates.

Area of Science:

• Materials Science
• Nanotechnology
• Metrology

Background:

• Integrated circuit (IC) feature sizes are rapidly shrinking, demanding advanced dimensional metrology.
• Current metrology techniques like X-ray, optical scattering, and microscopy have limitations.
• Accurate characterization of nanostructures is crucial for IC development and manufacturing.

Purpose of the Study:

• To demonstrate Reflection Small Angle Electron Beam Scattering (RSAES) for characterizing nanostructures.
• To validate RSAES as an efficient and accurate non-destructive measurement technique.
• To assess RSAES for features on flat and opaque substrates.

Main Methods:

• Utilized focused electrons scattered at angles <1° in reflection mode.
• Employed electron optics similar to transmission electron microscopy.
• Combined experimental proof-of-concept with rigorous electron reflection simulations.

Main Results:

• Demonstrated RSAES for characterizing nanostructure dimensions and shape.
• Validated the technique for features less than 10 nm in size.
• Showcased RSAES's efficiency and accuracy on opaque substrates.

Conclusions:

• RSAES is an effective method for non-destructive measurement of nanoscale features.
• The technique shows high accuracy and efficiency for sub-10 nm structures.
• RSAES provides a valuable tool for metrology in semiconductor manufacturing.