Overview
IEC/TR 63258:2021 - published by the International Electrotechnical Commission (in collaboration with ISO) - is a Technical Report that provides a practical, measurement-focused guideline for using ellipsometry to evaluate the thickness of nanoscale films. It does not specify or certify ellipsometer hardware; instead it describes procedures, data‑reporting practices and analysis approaches intended to minimize data variation and improve reproducibility in thin‑film characterization.
Key topics
- Scope and intent: Practical protocol for ellipsometry applied to nanoscale films; emphasis on reproducible results rather than instrument specifications.
- Measurement procedure: Sample preparation and system checks using reference samples (e.g., thermally grown SiO2/Si), alignment (height/tilt), measurement steps and handling to reduce systematic error.
- Ellipsometry fundamentals: Measurement of polarization changes represented by Ψ (amplitude ratio) and Δ (phase difference); key optical components (light source, polarizer, analyser, detector).
- Data reporting: Recommended content and structure for reporting measurement results to ensure traceability and comparability.
- Data analysis and validation: Guidance on setting analysis models, fitting strategies and validating fit results to ensure meaningful thickness and optical‑constant extraction.
- Dispersion and material models: Documented analysis methods include the Cauchy model, Sellmeier equation, Drude model, Lorentz (classical) model, Forouhi‑Bloomer, and Tauc‑Lorentz - covering transparent, conductive and amorphous materials.
- Case studies: Examples such as interlaboratory comparison using SiO2/Si wafers and additional material measurements to illustrate protocol application and reproducibility considerations.
- Normative reference: ISO/TS 80004‑1 (Nanotechnologies - Vocabulary) is cited for terminology.
Applications and who uses it
IEC/TR 63258 is practical for professionals and organizations performing nanoscale thin‑film characterization, including:
- Materials scientists and nanotechnology researchers evaluating film thickness, roughness, composition and optical constants.
- Metrology and calibration laboratories conducting interlaboratory comparisons and striving for reproducible ellipsometry data.
- Quality control engineers in semiconductor, photonics and coating industries who monitor thin‑film processes.
- Device and equipment developers using ellipsometry data to validate thin‑film growth systems and process control.
Practical benefits include improved data reproducibility, standardized reporting for comparison across labs, and guidance on selecting and validating appropriate dispersion models for different material classes.
Related standards
- ISO/TS 80004‑1 - Nanotechnologies - Vocabulary (normative reference used in IEC/TR 63258).
Keywords: ellipsometry, nanoscale films, film thickness measurement, optical constants, data reproducibility, dispersion models, nanotechnologies, thin‑film characterization.