| Zugriffsnummer | 29614 |
| Dokumenttyp | Buchartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Dimensional measurements |
| Autor(in); Institution |
Klapetek, Petr; CMI, Brno, CZECH REPUBLIC
Dziomba, Thorsten; 5.2, Dimensionelle Nanometrologie, PTB-Braunschweig
|
| Quelle/Jahr | Quantitative data processing in scanning probe microscopy : SPM applications for nanometrology:(2013), 81 - 125 |
| Herausgeber(in) |
Klapetek, Petr
|
| ISBN | 978-1-4557-3058-2 ; 978-1-4557-3059-9 (online) |
| DOI | |
| Verlag | Amsterdam: Elsevier |
| Freie Schlagworte | Rastersondenmikroskopie ; SPM ; Normung ; Richtlinien ; Normale |
| Zusammenfassung | Measurement of sample topography is performed in virtually any scanning probe technique, being or being not amended by some other physical quantity values, depending on the concrete technique. Topography measurements are therefore often understood as the simplest ones. This is also supported by fact, that the topography measurements are nearly the only result used for practical metrology at the nanoscale. As we will show in this chapter, there are many caveats that we need to envisage if we want to perform accurate dimensional measurement by any SPM technique. In this chapter we describe the force feedback technique for preserving constant tip-sample distance and we introduce its simplest application which is atomic force microscopy (AFM). This is the method nowadays predominantly used for nano- and microscale topography measurements in ambient conditions. Already briefly introduced in Chapter 2, it is based on the detection of interatomic forces that are used as a feedback source for the tip-sample distance control. Most of the methods described in the following chapters are derived from it, using the same instrumentation for the force measurements, nearly the same probes, and providing simultaneously the same dimensional data channels. When we will discuss here dimensional measurements and their uncertainties, we will refer to AFM for simplicity, but the same can be said about all the derived techniques (C-AFM, MFM, EFM, SThM, etc.). The only exceptions are scanning tunneling microscopy discussed in Chapter 10, which uses a different feedback principle, and in some cases also near-field scanning optical microscopy, which uses a different force probing instrumentation. First of all we will explain more in detail the force feedback scanning technique in both contact and non-contact mode, showing the basic theoretical relations and discussing artifacts that could be related to the method principle. Some of these relations will be treated also in the next chapter, discussing more in detail different components of tip-sample interaction. The basic direct and statistical quantities that can be derived from AFM measurements will be discussed as well in this chapter, focusing on covering all the basic quantities (vertical and lateral distances, roughness, etc.), instead of mentioning all the numerous results that can be extracted from a height field. In the second part of this chapter we discuss the dimensional measurements more in detail from a quantitative point of view, focusing on errors and uncertainties that we may face, and providing examples for their processing and evaluation. An important part is related to SPM calibration for dimensional measurements and to tip-sample convolution effects, these being the most problematic error source in SPM dimensional measurements. Note that in this chapter we will treat the probe and sample as rigid bodies, omitting mechanical compliance of both probe and sample and even omitting more complex force dependence (e.g. capillary force) that are discussed in the next chapter. This is a relatively strong approximation, as we can expect that nanoscale objects will have tendencies to be deformed under load. Even if the forces are very small, local pressures can be relatively high as the contact area between probe and sample can be in the order of square nanometers. However, the rigid bodies assumption can be useful to estimate many different phenomena and is still a basis of nearly all the dimensional measurements that are performed using scanning probe microscopy. |
