Fundamental Principles of Engineering Nanometrology

By Richard Leach

Working at the nano-scale demands an understanding of the high-precision measurement techniques that make nanotechnology and advanced manufacturing possible. Richard Leach introduces these techniques to a broad audience of engineers and scientists involved in nanotechnology and manufacturing applications and research. He also provides a routemap and toolkit for metrologists engaging with the rigor of measurement and data analysis at the nano-scale. Starting from the fundamentals of precision measurement, the author progresses into different measurement and characterization techniques.

The focus on nanometrology in engineering contexts makes this book an essential guide for the emerging nanomanufacturing / nanofabrication sector, where measurement and standardization requirements are paramount both in product specification and quality assurance. This book provides engineers and scientists with the methods and understanding needed to design and produce high-performance, long-lived products while ensuring that compliance and public health requirements are met.

Updated to cover new and emerging technologies, and recent developments in standards and regulatory frameworks, this second edition includes many new sections, e.g. new technologies in scanning probe and e-beam microscopy, recent developments in interferometry and advances in co-ordinate metrology.

• Demystifies nanometrology for a wide audience of engineers, scientists, and students involved in nanotech and advanced manufacturing applications and research
• Introduces metrologists to the specific techniques and equipment involved in measuring at the nano-scale or to nano-scale uncertainty
• Fully updated to cover the latest technological developments, standards, and regulations

• Language: English
• Publisher: Elsevier Science
• Release date: May 17, 2014
• ISBN: 9781455777501

Richard Leach

Richard Leach is a Principal Research Scientist in the Mass & Dimensional Group, Industry & Innovati

Book preview

Chapter 1

Introduction to Metrology for Advanced Manufacturing and Micro- and Nanotechnology

Richard Leach

This chapter introduces nanotechnology and advanced manufacturing, and discusses their metrology requirements. Nanotechnology and nanometrology strategies for a handful of countries are discussed along with a brief introduction to the standardisation efforts worldwide. The field of engineering nanometrology is introduced and the contents of the book are described, concentrating on what is new in the second edition.

Keywords

Nanotechnology; Nanometrology; Advanced Manufacturing; Standardisation; Engineering Nanometrology

Chapter Outline

1.1 What is engineering nanometrology? 4

1.2 The contents of this book and differences to edition 1 4

References 5

Since the beginning of humanity, our societies have been based on commerce, that is we make things and we sell them to other people. Relatively simple beginnings led to the Industrial Revolution and now to the technological age. Overgeneralising, the Far East are currently the masters of mass manufacture and the West are (or wish to be) the masters of advanced manufacture – the production of high-value goods, often involving a high level of innovation. To be able to manufacture goods in a cost-effective, environmentally sustainable manner, quality control procedures are required. And quality control in turn requires appropriate traceable metrology infrastructures to be in place. It is a subset of this metrology infrastructure that is the subject of this book. Whilst the rest of this chapter focusing on nanotechnologies, many of the arguments apply to advanced manufacturing in general.

There are many stories of wonderful new machines and changes in lifestyle that will be brought about by the commercial exploitation of nanotechnology (see, e.g. Refs. [1–5]). Nanotechnology (and nanoscience) is a pervasive technological discipline that allows manufacturers to design the functionality of a product by using the novel dimensional, chemical, material, mechanical and electromagnetic properties found at the nanoscale. As products based on aspects of nanotechnology increasingly enter the commercial marketplace, for example in sun protection creams or sports equipment, quality control of the manufacturing process is required, particularly where product characteristics at the nanoscale are of concern, for example potential health risks or other performance requirements.

In the next decade, nanotechnology can be expected to approach maturity, as a dominant, enabling technological discipline with widespread application. The principal drivers for the development of nanotechnology are likely to shift from an overarching focus on the ‘joy of discovery’ towards the requirement to fulfil societal needs [6]. Challenges relating to water conservation, energy management and the ageing population will need addressing [7], along with ambitions such as those specified in Europe 2020 (the EU’s growth strategy for the coming decade for a smart, sustainable and inclusive economy) [8].

Key nanotechnology markets today are in pharmaceuticals, electronics and materials. For these, and newly emerging or assimilating markets, competitive advantage will require a rigorous understanding of the principles and methods of nanotechnology. This in turn will require metrology with higher resolution and accuracy than has previously been envisioned. Fundamentally, new measurement techniques and standards must be developed to support such an understanding.

The existing measurement infrastructure must be extended into the nanoscale and beyond, to bring nanotechnology-based products, or manufacturing processes, successfully and safely into the marketplace [9]. Such an infrastructure must provide the ability to measure in three dimensions with high resolution over large areas. For industrial applications, this must also be achieved at a suitable speed or throughput [10,11].

Measurements in the micrometre and nanometre range should be traceable back to internationally accepted units of measurement (e.g. the metre). This requires common, validated measurement methods, calibrated instrumentation and qualified reference samples. In some areas, even a common vocabulary needs to be defined, although there has been progress in this area [12]. A traceability chain for the required measurements in the nanometre range has been established in only a few special cases, and often only for very specific measurement scenarios [10].

In 2011, the EU project Co-nanomet was completed and the main output was a common strategy for European nanometrology [13], such that future nanometrology development in Europe could build from its many current strengths. In this way, European nanotechnology can be supported to reach its full and most exciting potential. Co-nanomet established a set of goals and objectives for European nanometrology for the next decade.

In the United States, the National Nanotechnology Initiative (NNI), first established in 2001, has since coordinated the activity of the US Government in nanotechnology. In 2013, the NNI budget was $1.8 billion and there are 26 Federal agencies involved – including both research and regulatory organisations. In 2011, the NNI published a strategic plan [14], which aims to ensure that advancements in, and applications of, nanotechnology R&D to agency missions, and the broader national interest, continue unabated by laying out guidance for agency leaders, programme managers, and the research community regarding planning and implementation of nanotechnology R&D investments and activities.

Progress in nanotechnology and advanced manufacturing is not just of interest at the academic level. There is a considerable advantage in being able to reach a sufficient number of markets with new devices and materials to be able to recover development costs. There is consequently much effort devoted not only to development of devices and materials, but also to maximising market uptake and transfer of technology from the research stage, through production, out to the commercial marketplace. In many cases, examination of the barriers preventing successful uptake of new technology reveals some areas of metrology where there needs to be more research than is carried out at the moment. Also, metrology does not just allow control of production but also legal, ethical and safety issues [15,16] to be settled in a quantitative and informative manner.

There is a major thrust in standardisation for micro- and nanotechnology (MNT) activities in many national and regional committees. The International Organization for Standardization (ISO) has ISO technical committee (TC) 229 which has been running since 2005. The International Electrotechnical Committee (IEC) also established TC 113 around the same time to complement electrical activities. Recognising that there is an intersection between matter and radiation at the MNT level, several of the working groups are collaborations between ISO and IEC. The Joint Working Groups (JWGs) are divided into terminology and nomenclature (JWG1), measurement and characterisation (JWG2) and two sole ISO WGs on health, safety and environment (WG3) and product specifications and performance (WG4). The main work of the committees so far has been to define common definitions for nanotechnology (there are nine published standards and several in development) and to issue reviews of handling engineered nanomaterials in the workplace. Measurement and characterisation standards are currently being developed, especially for carbon nanotube analysis, but also for the generation and measurement of nano-object aerosols. In addition to this, a standard has been published on the definition and characterisation of artificial gratings at the nanoscale.

In recent years, there has been a move towards pre-regulatory activities in definitions and classifications for MNT. The EC recently published a recommendation for the definition of nanomaterials (2011/696/EU) and several countries (especially France) have introduced mandatory reporting requirements for research and industry, which could be interpreted as the start of regulation. In support of this, the EC has mandated (Mandate M461) work on standards development for the European area through CEN TC 352.

There are many other well-established and related ISO committees that are not exclusively MNT but cover aspects of engineering nanometrology; for example, ISO TC 213, which covers surface texture standards (see Chapter 6), ISO TC 201, which covers many of the standardisation issues for scanning probe microscopes (see Chapter 7), and ISO TC 209 (cleanroom technologies) is also forming a working group (WG10) on nanotechnology considerations. ISO TC 24/SC4 (Particle Characterisation) is actively liaising with ISO TC 229 in developing new standards. Trends in the future may look at interesting new materials and nanostructured systems such as graphene and ultrafine bubbles.

This book considers a subset of the metrology that will be required in the near future to support a standards infrastructure for nanotechnology and many other fields of advanced manufacturing. If interchangeability of parts is to become a reality, then fabrication plants need to move away from ‘in-house’ or ‘gold’ standards, and move towards measurement standards and techniques that are traceable to national or international realisations of the measurement units [17].

1.1 What is engineering nanometrology?

The field of engineering metrology relates to the measurement and standardisation requirements for manufacturing. In the past, engineering metrology mainly covered dimensional metrology, that is the science and technology of length measurement (see Refs. [18,19]). Modern engineering metrology usually encompasses dimensional plus mass and related quantity metrology. Some authors have also incorporated materials metrology into the fold [20] and this is an important inclusion. However, this book will concentrate on the more traditional dimensional and mass areas. This choice is partly to keep the scope of the book at a manageable level and partly because those are the areas of research that the author has been active in.

So, engineering nanometrology is traditional engineering metrology at the MNT scale. Note that whilst nanotechnology is the science and technology of structures varying in size from around 0.1 nm to 100 nm, nanometrology does not only cover this size range. Nanometrology relates to measurements with accuracies or uncertainties in this size range (and smaller). For example, one may be measuring the form of a 1 m telescope mirror segment to an accuracy of 10 nm.

It is important to realise that there are many areas of MNT measurement that are equally as important as dimensional and mass measurements (see Refs. [10,13] for a treatment of all the areas). Other areas not included in this book are measurements of electrical, chemical and biological quantities, and the wealth of measurements for material properties, including the properties of particles. There are also areas of metrology that could well be considered engineering nanometrology but have not been covered by this book. These include the measurement of roundness [21], thin films (primarily thickness), X-ray computed tomography [22] and the dynamic measurement of vibrating structures. Once again, the choice of contents has been dubiously justified above.

1.2 The contents of this book and differences to edition 1

The field of engineering nanometrology is rapidly advancing, and any text book on the subject will be out of date almost as soon as it is published. Edition 2 has been produced for this reason. Edition 2 updates the research literature, provides the latest information on standards and, where appropriate, introduces new measurement and characterisation techniques. Some additions to the basic information have also been included.

This book is divided into 10 chapters. Chapter 2 gives an introduction to measurement, including short histories of, and the current unit definitions for, length, angle, mass and force. Basic metrological terminology is introduced, including the highly important topic of measurement uncertainty. The laser is presented in Chapter 2, as it is a very significant element of many of the instruments described in this book.

Chapter 3 reviews the most important concepts needed when designing or analysing precision instruments. Chapter 4 covers the measurement of length using optical interferometry and discusses the concepts behind interferometry, including many error sources. Chapter 5 reviews the area of displacement measurement and presents most modern forms of displacement sensor. The field of surface texture measurement is covered in the next three chapters, as it is a very large and significant topic. Chapter 6 covers stylus and optical surface measuring instruments, and Chapter 7 covers scanning probe and particle beam instruments. Both Chapters 6 and 7 include instrument descriptions, limitations and calibration methods. Chapter 8 presents methods for characterising surfaces, including both profile and areal techniques. Chapter 9 introduces the area of coordinate metrology and reviews the latest developments with micro-coordinate measuring machines. Lastly, Chapter 10 presents a review of the latest advances in low mass and force metrology.

References

1. Storrs Hall J. Nanofuture: What’s Next for Nanotechnology Prometheus Books 2005.

2. Mulhall D. Our Molecular Future: How Nanotechnology, Robotics, Genetics and Artificial Intelligence Will Transform Our Future Prometheus Books 2002.

3. Nanoscience and Nanotechnologies: Opportunities and Uncertainties, Royal Society and Royal Academy of Engineering, 2004.

4. Binns C. Introduction to Nanoscience and Nanotechnology: Tiny Structure, Big Ideas and Grey Goo Wiley–Blackwell 2010.

5. Ramsden J. Nanotechnology: An Introduction Amsterdam: Elsevier; 2011.

6. Nanotechnology Research Directions 2020, NSF, WTEC report, September 2010.

7. MacLurcan D. Nanotechnology and Global Sustainability CRC Press 2012.

8. Europe 2020, A strategy for smart, sustainable and inclusive growth, European Commission. <ec.europa.eu/eu2020/index_en.htm>.

9. Bogue R. Nanometrology: a critical discipline for the twenty-first century. Sensor Rev.