Nanometrology

Nanometrology is the science and technology of measuring structures and properties at the nanometre scale. It underpins the fabrication, quality control and application of advanced materials and devices, from semiconductor circuits to nanocomposite coatings and biomedical probes. By combining precision instrumentation and rigorous data analysis, nanometrology provides traceable measurements of length, topology, force, optical response, composition and other parameters with uncertainties down to fractions of a nanometre or femtonewtons. Key tools include scanning probe methods (atomic force and scanning tunnelling microscopy), electron- and X-ray‐based imaging, optical scatterometry and spectroscopy, ion-beam techniques and single-particle mass spectrometry. Together these methods enable characterisation of surface roughness, crystal defects, thin-film thickness, strain fields, nanostructure dimensions and interparticle interactions. Nanometrology serves both research and industry by ensuring reproducibility, facilitating metrological traceability and guiding the design of devices whose performance depends critically on nanoscale precision.

Research from Nature Portfolio

Dynamic atomic force and scanning tunnelling microscopy has been used to distinguish individual titanium and oxygen atoms on an anatase TiO₂(101) surface. By integrating force-distance spectroscopy with tunnelling current measurements and first-principles modelling, researchers unambiguously assigned surface species and probed common defect centres under vacuum, establishing a protocol for atomic-site identification on wide bandgap materials. Another study demonstrated full-wave rectification of terahertz pulses using ring-shaped quantum barrier loops. Ultrafast optical excitation induced eddy currents around nanoscale tunnelling junctions, whose geometry and incident polarisation controlled the net tunnelling current. This work paves the way for centimetre-scale THz circuitry and quantum-limited rectifiers. A further advance achieved record electric-field enhancements (~1.4×10⁴) at gigahertz frequencies by employing split-ring resonators with nanometre-sized gaps. Near-field mapping and electromagnetic simulation confirmed sub-diffraction-limit confinement, enabling coherent excitation of molecular and lattice modes at unprecedented field strengths.

Nanometrology publication trend

The graph below shows the total number of articles in nanometrology across all publications each year (not limited to Nature Index journals).

Technical terms

Atomic force microscopy (AFM): A scanning probe technique that measures forces between a sharp tip and a surface to map topography and mechanical properties at nanometre resolution.

Optical scatterometry: A non-imaging diffraction-based method that infers nanoscale grating dimensions by measuring and modelling angle- or wavelength-dependent reflectance or ellipsometric signals.

Rutherford backscattering spectrometry (RBS): An ion beam analysis method in which energetic ions scatter elastically from nuclei, providing quantitative depth profiles of elemental composition near the surface.

Single-particle ICP-MS (spICP-MS): A time-resolved mass spectrometric technique that detects individual nanoparticles by recording transient ion signals in a plasma, yielding size and number concentration information.

Terahertz field enhancement: Concentration of electromagnetic energy in nanoscale gaps or resonant structures at frequencies between microwaves and infrared, often exceeding 10⁴-fold intensity amplification.

Zeta potential: The electric potential at the slipping plane of a particle in suspension, governing colloidal stability and interparticle interactions.

Bragg diffraction: Elastic scattering of waves (X-rays, electrons) from periodic atomic planes, used in crystallography and nanoscale defect metrology.

Ellipsometric angles (Ψ, Δ): Parameters describing changes in polarization upon reflection; Ψ is the amplitude ratio angle and Δ is the phase difference angle, sensitive to nanoscale film thickness and refractive index.

References

1. Atomic species identification at the (101) anatase surface by simultaneous scanning tunnelling and atomic force microscopy. Nature Communications (2015).
2. Terahertz rectification in ring-shaped quantum barriers. Nature Communications (2018).
3. Giant Electric Field Enhancement in Split Ring Resonators Featuring Nanometer-Sized Gaps. Scientific Reports (2015).
4. Thin film depth profiling by ion beam analysis. Analyst (2016).
5. Enhanced accuracy through machine learning-based simultaneous evaluation: a case study of RBS analysis of multinary materials. Scientific Reports (2024).
6. Analytical methods for identification, characterization, and quantification of metal-containing nanoparticles in biological and biomedical samples, food and personal care products. TrAC Trends in Analytical Chemistry (2024).