Mapping spectroscopic micro-ellipsometry with sub-5 microns lateral resolution and simultaneous broadband acquisition...

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Spectroscopic ellipsometry is crucial for thin film analysis but limited in micro-structure applications due to resolution and speed constraints.
• Existing techniques struggle with precise optical property and thickness determination of nanoscale features.

Purpose of the Study:

• To develop and validate a Spectroscopic Micro-Ellipsometer (SME) with enhanced lateral resolution and rapid data acquisition.
• To enable accurate optical characterization of micro- and nano-scale structures.

Main Methods:

• Introduction of a Spectroscopic Micro-Ellipsometer (SME) integrated into standard optical microscopes.
• Simultaneous, spectrally resolved ellipsometric data acquisition at multiple angles of incidence within seconds.
• Achieved lateral resolution down to 2 μm in the visible spectral range.

Main Results:

• Demonstrated accurate complex refractive index and thickness measurements, validated against a commercial spectroscopic ellipsometer.
• Generated high-resolution optical property and thickness maps over micron-scale areas.
• Successfully characterized optical properties and layer counts of transition-metal dichalcogenides and graphene micro-structures.

Conclusions:

• The SME overcomes limitations of conventional spectroscopic ellipsometry for micro-structure analysis.
• The developed instrument provides high accuracy, rapid measurements, and excellent lateral resolution.
• SME is a powerful tool for characterizing advanced nanomaterials like 2D transition-metal dichalcogenides and graphene.