Pilot study on calibration of micro-nanoscale 3D standards
Project Description
This comparison aims to compare the calibration performance of a novel kind of micro-nanoscale 3D standard, which is a landmark-based sample developed by BAM and PTB. Compared to conventional nanoscale standards (i.e.,step heights and 1D/2D gratings), this 3D standard allows a complete 3D calibration with just one type of standard, offering different advantages. Today, 3D standards are increasingly applied for calibrating atomic force microscopes (AFM), (stereogrammetric) Scanning Electron Microscopes (SEM) and Confocal Laser Scanning Microscopes (CLSM). Up to now, no comparison has been carried out to verify the calibration performance of 3D standards. Due to the (much) higher complexity in the calibration of the 3D standards in comparison to conventional standards, a study on this topic is highly required. This pilot study is intentionally restricted to a small group of NMIs (PTB, NMIJ, NPL and BEV) to achieve (i) a better “proof of concept” with reasonable work efforts and duration of the project, (ii) a reduction of the risk of sample altering and/or contamination during measurements. Two 3D standards will be used: 40µm x 40µm x 1.8µm; 80µm x 80µm x 3µm.
The company point electronic (Erich Neuß Weg 15, D-06120 Halle (Saale), Germany) will support the comparison by providing the 3D standards and data evaluation software.
Progress Report 2026-08-17
Two 3D standards were manufactured by the project partner point electronic GmbH using FIB techniques for the comparison. The standards were calibrated by PTB using the NMM1 within the scheduled timeframe, i.e. before 28 February 2023.
The standards were measured by NMIJ between 1 March and 30 April 2023.
However, during the measurements, NMIJ identified a significant instability in its metrological AFM, which was probably caused by an interferometer module integrated into the instrument.
The AFM is approximately 25 years old and can no longer be serviced by the manufacturer. Although funding has been requested to procure a replacement system, no procurement timeline has yet been established. Consequently, NMIJ officially withdrew from the pilot study in August 2025.
As scheduled, the standards were forwarded by NMIJ to NPL on 30 April 2023. Unfortunately, the MAFM at NPL has been undergoing an extensive upgrade and is still not operational. It is currently expected to become operational later in 2026, after which the required validation measurements can be performed.
If the scheduled measurements at NPL cannot be completed by October 2026, the standards will be returned to PTB, where a calibration using the second NMM is planned.
This would at least enable an intercomparison between the NMM1 and NMM2.
The standards would subsequently be forwarded either to NPL or BEL, depending on the readiness and availability of their measurement systems.
NMIJ (National Metrology Institute of Japan) is no longer taking part in this project.
Progress Report 2023-10-05
The current status is as follows:
The samples were manufactured by the company "point electronic GmbH" as scheduled.
PTB has measured the 2 samples as planned. NMIJ has measured one sample MMC-40 ID942 as scheduled. However, they had detected an instability issue in their measurement device. Currently, the samples are at NPL.
BEV is interested to measure the samples after the pilot study has been finished, to verify their measurement tool only. BEV does not intend to have their results included in the comparison report.
Partners of the pilot study had a meeting during the Nanoscale Conference in Helsinki and aligned the next actions of the study. It is agreed that the pilot study will be extended by one year, preferably to 31.12.2024, thus to offer more time for (i) NMIJ to debug their metrology tool to solve the instability issue; (ii) NPL to gain more measurement experience and (iii) PTB to prepare the 2nd NMM (NMM2) for joining the comparison in extra.