Y₂O₃ optical constants between 5 nm and 50 nm

Area of Science:

• Materials Science
• Optics
• Thin Film Physics

Background:

• Yttrium oxide (Y2O3) is a promising material for optical coatings and semiconductor applications.
• Accurate optical constants are crucial for designing and modeling Y2O3-based devices.
• Previous measurements of Y2O3 optical properties have shown variability.

Purpose of the Study:

• To accurately determine the optical constants (refractive index and extinction coefficient) of e-beam evaporated Y2O3 thin films.
• To investigate the optical properties in the extreme ultraviolet (EUV) range (5-50 nm).
• To compare experimental results with theoretical calculations and existing literature data.

Main Methods:

• Angle-dependent reflectance measurements using synchrotron radiation at the Advanced Light Source.
• Fitting experimental reflectance data to extract optical constants and thin film roughness.
• Characterization using ellipsometry and atomic force microscopy (AFM).

Main Results:

• Optical constants for Y2O3 thin films were determined between 5 and 50 nm.
• The refractive index near 36 nm was found to be significantly lower than previously reported values.
• The real part of the optical constants was 10-15% lower than CXRO values between 17-30 nm.

Conclusions:

• The study provides reliable optical constants for Y2O3 thin films in the EUV spectral region.
• Discrepancies with previous data highlight the importance of measurement conditions and techniques.
• The results aid in the precise application of Y2O3 in advanced optical and electronic devices.