Overview
ISO 23830:2008 - Surface chemical analysis - Secondary‑ion mass spectrometry (SIMS) - specifies a practical method to confirm the repeatability and constancy of the positive‑ion relative‑intensity scale in static SIMS instruments. The standard is intended for general analytical use, applies only to instruments that use an electron gun for charge neutralization, and is not a full calibration of the intensity/mass response function. Instead, it provides a routine check to detect drift and variability of relative peak intensities as instruments are used.
Key topics and requirements
- Reference sample: Uses commercially available poly(tetrafluoroethylene) (PTFE) tape (domestic plumbing type) as the reference material; discard the first ~20 cm of tape and use fresh surface samples.
- Sample handling and mounting: Handle with clean metal tweezers and powder‑free polyethylene gloves; do not clean the PTFE or use adhesive tape; mount flat on a conducting backing and avoid placing the sample over holes.
- Instrument applicability: Applies to static SIMS instruments with charge stabilization (electron gun) and addresses positive ions only; negative ions are excluded due to surface potential control issues.
- Measurement procedure: Acquire a defined sequence of spectra (seven repeated spectra are used in the method) to derive repeatability standard deviations and to evaluate drift (constancy) of relative intensities over time.
- Operational controls: Guidance on spectrometer settings that affect stability - beam centering/defocus, rastering, acquisition time and ion fluence - is provided. The method specifies limits to keep measurements in the static SIMS regime and gives example conditions (for example, a 0.5 pA beam with a 200 µm raster and 128 s acquisition in the illustrative example).
- Frequency: Re-assessments are recommended at regular intervals (the standard notes repeat measurements at intervals no longer than three months, using a fresh sample from the same reel).
Practical applications
- Routine performance checks for static SIMS laboratories to confirm instrument stability before analytical campaigns.
- Quality control for surface analysis workflows where relative peak intensities are used for identification or semi‑quantitative comparison.
- Supporting spectral library matching and historical data consistency by ensuring the instrument’s relative‑intensity scale has not drifted.
- Diagnostic tool to identify when remedial action (re‑setting parameters, service or manufacturer calibration) is needed.
Who should use this standard
- Surface analysis scientists, SIMS operators, lab managers, and QA personnel in materials, polymer, semiconductor and surface‑chemistry laboratories that perform static SIMS.
- Instrument manufacturers and service engineers as a routine check complementary to formal instrument calibrations.
Related guidance
- ISO 23830:2008 complements manufacturer calibration procedures (the standard explicitly states that intensity/mass response calibration may be performed by the instrument manufacturer or other bodies).
- Prepared by ISO/TC 201 (Surface chemical analysis), Subcommittee SC 6 (SIMS), and intended to be used alongside lab SOPs for static SIMS operation.