Overview
IEC/TS 62622:2012 - published by the International Electrotechnical Commission in collaboration with ISO TC 229 - is a technical specification for artificial gratings used in nanotechnology. It defines generic terminology and dimensional quality parameters for gratings (interpreted as deviations from nominal feature positions), and provides guidance on categorizing measurement and evaluation methods. The specification focuses principally on one-dimensional (1D) and two-dimensional (2D) gratings and aims to improve communication and quality assurance between manufacturers, users and calibration laboratories.
Key topics
- Terminology and definitions for grating features, reference planes and quality parameters (global and local).
- Grating types and pattern descriptions (1D line gratings, 2D lattices) including geometric considerations such as Bravais lattices.
- Dimensional quality parameters expressed as deviations from nominal positions (pitch, straightness, periodicity, local defects).
- Measurement method categories:
- Global methods (whole-grating characterization),
- Local methods (feature-by-feature inspection),
- Hybrid methods (combined approaches).
- Calibration and characterization methods applicable to metrological instruments (e.g., SEMs, scanning probe microscopes) and encoder systems.
- Deviations beyond nominal positions: out-of-axis, out-of-plane and other feature deviations.
- Filter algorithms and evaluation techniques for processing grating measurement data.
- Reporting and documentation: recommended content for calibration procedures, grating specifications and published quality parameters.
Applications
IEC/TS 62622 supports practical applications where grating dimensional quality directly impacts measurement or production outcomes:
- Semiconductor lithography - alignment and overlay control using grating-based feedback.
- Precision position feedback - length and angular encoder systems relying on grating accuracy.
- Metrology and calibration - artificial gratings as calibration standards for high-resolution microscopes (SEM, TEM, AFM/SPM).
- Quality assurance - suppliers and users assessing grating fitness for purpose to reduce measurement uncertainty.
Who should use this standard
- Grating manufacturers specifying and validating production tolerances.
- Calibration laboratories establishing traceable characterization procedures (aligned with ISO/IEC 17025).
- Metrology engineers and microscopy labs that use gratings to calibrate imaging scale and distortion.
- Process engineers in nanofabrication and semiconductor manufacturing who rely on grating-based alignment and encoders.
Related standards
IEC/TS 62622:2012 delivers a practical framework for defining, measuring and reporting grating dimensional quality - improving interoperability and reducing uncertainty where artificial gratings are used as functional components or calibration artifacts in nanotechnology.