Traceable Metrology Research Articles

Bringing real-time traceability to high-speed atomic force microscopy

In recent years, there has been growth in the development of high-speed AFMs, which offer the possibility of video rate scanning and long-range scanning over several hundred micrometres. However, until recently these instruments have been lacking full traceable metrology. In this paper traceable metrology, using optical interferometry, has been added to an open-loop contact-mode high-speed AFM to provide traceability both for short-range video rate images and large-area scans made using a combination of a high-speed dual-axis scanner and long-range positioning system. Using optical interferometry to determine stages’ positions and cantilever displacement enables the direct formation of images, obviating the need for complex post-processing corrections to compensate for lateral stage error. The application of metrology increases the spatial accuracy and linearisation of the high-speed AFM measurements, enabling the generation of very large traceable composite images.

Traceable metrology for large involute gears

Renewable energy systems are becoming more important due to the current energy transition, where the main share of renewables is derived from wind energy systems. However, failure rates due to critical drivetrain components need to be significantly reduced. Traceable quality management is necessary, but has not yet been established for the large-scale workpieces and their quality assurance. Measurement standards need to be made available for the manufacturing industry. A novel involute gear measurement standard with a diameter of about two metres has therefore been developed. After the first worldwide calibration process of a large-scale gear had been conducted, the measurement standard was used for an intercomparison between seven participants. Apart from the development of this measurement standard, the establishment of a calibration service was initiated, so that setting up quality assurance for large-scale gears is possible in the future.

A NIST perspective on metrology and EMC challenges for 5G and beyond

Wireless connectivity, the internet of things, smart technologies and applications will all create new EMC challenges, in both expected and unexpected forms. Traceable metrology needs to be developed, both to characterize and optimize these future systems, and to minimize interference and EMC problems. This paper looks at metrology and EMC challenges related to 5G and beyond communications, and what NIST is doing towards solutions.

2D surface optical lattice formed by plasmon polaritons with application to nanometer-scale molecular deposition

Surface plasmon polaritons, due to their tight spatial confinement and high local intensity, hold great promises in nanofabrication which is beyond the diffraction limit of conventional lithography. Here, we demonstrate theoretically the 2D surface optical lattices based on the surface plasmon polariton interference field, and the potential application to nanometer-scale molecular deposition. We present the different topologies of lattices generated by simple configurations on the substrate. By explicit theoretical derivations, we explain their formation and characteristics including field distribution, periodicity and phase dependence. We conclude that the topologies can not only possess a high stability, but also be dynamically manipulated via changing the polarization of the excitation laser. Nanometer-scale molecular deposition is simulated with these 2D lattices and discussed for improving the deposition resolution. The periodic lattice point with a width resolution of 33.2 nm can be obtained when the fullerene molecular beam is well-collimated. Our study can offer a superior alternative method to fabricate the spatially complicated 2D nanostructures, with the deposition array pitch serving as a reference standard for accurate and traceable metrology of the SI length standard.

Atomic force microscope adhesion measurements and atomistic molecular dynamics simulations at different humidities

Due to their operation principle atomic force microscopes (AFMs) are sensitive to all factors affecting the detected force between the probe and the sample. Relative humidity is an important and often neglected—both in experiments and simulations—factor in the interaction force between AFM probe and sample in air. This paper describes the humidity control system designed and built for the interferometrically traceable metrology AFM (IT-MAFM) at VTT MIKES. The humidity control is based on circulating the air of the AFM enclosure via dryer and humidifier paths with adjustable flow and mixing ratio of dry and humid air. The design humidity range of the system is 20–60 %rh. Force–distance adhesion studies at humidity levels between 25 %rh and 53 %rh are presented and compared to an atomistic molecular dynamics (MD) simulation. The uncertainty level of the thermal noise method implementation used for force constant calibration of the AFM cantilevers is 10 %, being the dominant component of the interaction force measurement uncertainty. Comparing the simulation and the experiment, the primary uncertainties are related to the nominally 7 nm radius and shape of measurement probe apex, possible wear and contamination, and the atomistic simulation technique details. The interaction forces are of the same order of magnitude in simulation and measurement (5 nN). An elongation of a few nanometres of the water meniscus between probe tip and sample, before its rupture, is seen in simulation upon retraction of the tip in higher humidity. This behaviour is also supported by the presented experimental measurement data but the data is insufficient to conclusively verify the quantitative meniscus elongation.

A Traceable Metrological Method with Nanometer Scale Resolution for Micro-Structure

Micro-structure dimension metrology is a grand challenge to current metrological methods and tools. In this paper, a retraceable metrological scanning electron microscopy (M-SEM) system with precision stage and laser interferometer is presented in detail. The double stages structure is used to realize both sample positioning in 50mm×50mm range and accuracy imaging in several tens of micron scale. In order to acquiring metrological scanning image, the control system based on digital signal processing (DSP) is constructed. Furthermore, this paper focuses on demonstrating a metrological SEM image edge detection algorithm which is the essential part of the metrological SEM system to realize the traceable metrology of line width.

Traceable metrology for characterizing quantum optical communication devices

Industrial technologies based on the production, manipulation, and detection of single and entangled photons are emerging. Quantum key distribution is one of the most commercially advanced, and among the first to directly harness the peculiar laws of quantum physics. To assist the development of this quantum industry, the National Physical Laboratory is using traditional, and quantum, methods to develop traceable metrology for the devices used in these technologies. We report on the instrumentation we have developed to characterize such systems.

Improving Fuel Cell Industry by Constructing Metrological Traceability

Due to the reality of ninety five percent dependency of energy-importing, the diversification of kinds and sources of fuel like crude oil is making crucial and environmental issues in Taiwan. Efficient and zero emission fuel cell is a promising power source and expected to play a major role in the future energy supply. According to the fuel cell roadmap of the Bureau of Energy, Taiwan Ministry of Economic Affairs, and the projected annual output will reach NTD 13,000 million in 2020, thus, a recognized specification and traceable metrology is necessary to maintain the product quality and trade equity once the market is emerged. In this paper, we review the current status of fuel cell development and standards in Taiwan and then propose a solid fuel cell metrology which can be traced to international standards.

Special Issue on Measurement and Quality Control

It has now been recognized that prompt scientific and technological measures should be taken against the rapidly expanding globalization of common issues such as ecology, economy, energy, food, and safety. Measurements are the key to progress in the natural sciences and the major requirement for technological innovation. This special issue reviews manufacturing metrology and quality management evolution, where applications now range from macro- to micro- and nanoengineering. The articles presented point out their implications for science, engineering, and industry and highlight the latest in research, development, and potential applications of promising measurement and quality control techniques. These include specific applications in aerospace, automotive and transport, semiconductor devices, photonics, and manufacturing. Measurement and quality control are essential to industrial technology, as shown in cases of quality control of optical devices, the measurement of metal parts in the automotive industry, silicon wafer inspection in the semiconductor industry, and the study of biomedical chips. The developments in such main fields of interests as dimensional metrology in production engineering, laser metrology for precision measurement, and quality management methodology are enabling us to extend applications in emerging basic technologies. In most industrial applications, measurement of dimensional, geometrical, and mechanical quantities in the manufacturing process have changed significantly and globally due to an increasing demand for precision arising from the introduction of new manufacturing technologies and requirements for parts functionality. The requirements of precision engineering made it inevitable to establish traceable metrology supporting the international exchange of goods and the development of precise manufacturing processes. I am certain that this special issue will further strengthen the ongoing effort for attaining excellence inmeasurement science and technology and quality control. I sincerely hope this special issue will give many beginning and established researchers a chance to share 21st Century technology. Lastly, I thank the authors, reviewers, and editors for their invaluable advice, strong backup, and continuing cooperation that have helped ensure the success of this issue.

Traceable Dimension Metrology by AFM for Nanoscale Process Control

Your 32nm is different from my 32nm! The paradoxical statement reflects one of the most essential debates in the field of nanoscale dimension metrology for process control in the modern nanoelectronic manufacturing industry. This baffling debate is all about accuracy and traceability of dimension measurement systems used on production floors. As the circuit geometry and density continues to scale to the 45nm node and below, the metrology bias and uncertainty play a more significant role, and the characterization becomes more difficult. This article assesses the capability of atomic force microscope (AFM) as an accurate inline calibration metrology tool and the correlation of AFM measurement to NIST traceable standards. It introduces the methodology of adopting AFM as a traceable reference tool for CD SEM and optical scatterometry used in inline process control. The focus is on height, linewidth, and pitch calibrations due to their critical but challenging roles for process control in today’s nanoelectronic manufacturing. Care must be taken to minimize the impact from factors that affect the traceability and accuracy in the AFM system, including tip width calibration, tip wear, tip shape effect, contamination, and linewidth roughness.

Progress towards traceable nanometric surface metrology

It is not straightforward to relate measurements of surface topography made by different instruments because of the different geometrical and physical interactions between the measuring probe and the specimen surface. Improved correlation can be achieved if conditions are chosen so that these interactions are weak and this choice is facilitated by use of the instrumental amplitude-wavelength map. In order to provide traceable metrology NPL is constructing a precise measurement facility for use with different measuring probes and is also developing a range of artefacts for calibration purposes.