ISO 20263:2024

Overview - ISO 20263:2024 (Microbeam analysis, Analytical electron microscopy)

ISO 20263:2024 specifies a standardized procedure to determine the averaged interface position between two layered materials from cross‑sectional images. Applicable to images recorded by TEM or STEM and to cross‑sectional elemental maps from EDS or EELS, the method works with native digital images or images digitized from photographic film. It is intended for real experimental images (layer thicknesses from a few nanometres to a few micrometres) and explicitly does not apply to simulated interface positions generated by the multi‑slice simulation (MSS) method.

Key technical topics and requirements

• Scope and applicability

  • Cross‑sectional imaging of multi‑layered materials using TEM/STEM, and elemental mapping (EDS/EELS).
  • Digitized images from CCD/CMOS cameras, imaging plates, or scanned photographic film.

• Specimen preparation

  • Guidance on preparing cross‑sectional specimens (FIB thinning, ion‑milling, ultra‑microtomy are referenced concepts).
  • Requirements to ensure representative, artefact‑minimized images for interface analysis.

• Image analysis workflow

  • ROI (Region of Interest) selection and image classification to isolate the interface area.
  • Acquisition of an averaged intensity profile across the ROI.
  • Moving‑average processing to reduce noise and intensity fluctuations.
  • Differential processing (difference between adjacent profile points) to locate the interface transition.
  • Determination of the averaged interface position from processed profiles.

• Uncertainty and calibration

  • Procedures to estimate measurement uncertainty, including contributions from each processing step.
  • Pixel‑size calibration and scale unit considerations (see Annex C).

• Supporting material

  • Examples of processing real TEM/STEM images (Annex A) and principal applications of the method (Annex B).

Practical applications and users

This ISO standard is directly useful for:

• Materials scientists and electron microscopists performing layer thickness and interface characterization.
• Semiconductor manufacturers, coating and thin‑film developers, sensor and optical component producers for quality control, process verification and failure analysis.
• Laboratories producing cross‑sectional elemental maps (EDS/EELS) that require objective, repeatable interface position measurement.

Key practical benefits:

• Provides a reproducible, documented method to measure interface position and layer thickness from real cross‑sectional images.
• Improves comparability of results across labs and instruments by standardizing ROI selection, filtering and differential analysis.

Related standards

• ISO 29301 (image and detector terminology) - cited for camera and imaging plate definitions.
• ISO 15932 (TEM image processing terms) - cited for FFT/IFFT terminology.

Keywords: ISO 20263:2024, microbeam analysis, analytical electron microscopy, TEM, STEM, interface position, cross‑sectional imaging, EDS, EELS, ROI, moving average, differential processing.