Comparison of grating size measurements for AFM and SEM calibration

Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) have become essential instruments, particularly for measuring the dimensions of nanoscale networks and objects. They are widely used in both industry and academia. However, to provide metrologically reliable information (traceable to the International System of Units, SI) and therefore comparable, these instruments need to be periodically calibrated using reference networks that are themselves calibrated.

After calibration, and in order to verify the accuracy of the measurement returned by the instrument, a comparison exercise can also be initiated. To this end, the user compares his measurements with those delivered by another user, another instrument or another laboratory.

This type of comparison can be launched on a much larger scale to verify the measurement capabilities of a set of users on a national or even international scale.

For AFM and MEB, these comparisons are generally initiated by metrology institutes, with participants often familiar with the concepts of uncertainty and traceability at . These comparisons are based on very strict protocols discussed between institutes.

In France, despite the country's highly developed range of instruments, no such comparison had been launched before 2014. For this reason, the "Instrumentation" working group of the Club nanoMétrologie, following numerous requests from its members, has set up a national intercomparison campaign to measure the dimensional characteristics of standard arrays by AFM and SEM. This club, created in 2011 and piloted by the Laboratoire national de métrologie et d'essais (LNE) and the Centre national de compétences en nanosciences du CNRS (C'Nano – CNRS), is a national network of academic, industrial and institutional players involved in nanometrology, with over 400 members by 2022.

The aim of this comparison was to take stock of AFM and SEM measurement capabilities in France, on a reference sample, including instruments from different equipment manufacturers, integrated in various laboratories and for a panel...