Analytical Methods and Instruments for Micro- and Nanomaterials

X-ray techniques are non-destructive material analysis methods to provide information about lattice constant, strain, material composition, layer thickness, defect density, interface quality, grain size, texture, etc. This chapter begins with the basic definitions in crystallography and crystal defects, x-ray diffraction, and then the discussion extend to the x-ray applications for material analysis ranging from powder diffraction, and grazing-angle reflectivity measurements to high-resolution measurements. The content gives also examples for how to apply x-ray diffraction to study the nano-scale materials and devices.

Photoluminescence is a form of light emission from a material which is initiated by the excitation of the electronic system of the material by incident photons. New photons can then be emitted, as the excited electrons relaxes back to their ground states and the emitted photons can reveal important information of the electronic system of the material. Micro-photoluminescence, described in this chapter, is a versatile technique for characterization and studies of material optical properties on a smaller length scale. Basic principles and instrumentation are described and relevant examples are provided for heterostructures and nanostructured semiconductor materials with the focus on analysis of fundamental properties relevant for today’s applications.

This chapter presents the principles and applications of Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) techniques. These methods are other important varieties of using incident photons to study electronic and vibrational properties of materials, in addition to photoluminescence, described in Chap. 2. The discussion in this chapter covers the scientific and technical issues while several experimental examples highlight the significance and applications of each characterization technique in the fields of microelectronics engineering and material science.

The chapter presents the fundaments of electron and optical microscopes. It begins with an overview of microscopy and then continues to how the technique of electron spectroscopy developed to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for material analysis. A focus is made on electron diffraction and chemical analysis methods e.g. energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) techniques. The chapter covers also high-angle annular dark-field (HAADF) and low-angle annular dark-field (LAADF) techniques and their applications. Later, the discussions extend also to scanning Moiré fringe (SMF) imaging technique and how to determine the lattice plane direction and crystal quality. Finally, different examples of applications of electron microscopes for nano-scale materials and devices are presented.

The origin of Rutherford backscattering spectrometry (RBS) constitutes one of a handful of paradigm breaking physics experiments done in the early twentieth century that paved the way to modern physics and our conception of matter. From fundamental research in nuclear physics, RBS developed into a very useful material characterization technique for investigation of thin film composition, depth profiling of impurities, and thickness measurement in the nanometer range. This chapter introduces the foundation for the technique and how it is applied in modern materials analysis.

Among other characterization techniques, secondary ion mass spectrometry (SIMS) is of particular interest due to its unprecedented sensitivity and ability for detection of low concentrations of practically any element of the periodic table with large spatial resolution. At present time SIMS is a primary tool used in both industry and research areas and also highly relevant for analysis of nano-scaled materials. However, SIMS is a quite complicated technique, where deep understanding the physical processes involved is vitally required for a correct interpretation of the results obtained. Therefore, in the present chapter special attention is paid to the basic principles of SIMS as well as complicating factors affecting the measurements. In the first part of the chapter, devoted to the basics of SIMS, two fundamental processes (sputtering and ionization) are described in some detail. After that the main types of modern SIMS instruments are reviewed, describing the different primary ion sources and the variety of mass spectrometers for detecting secondary ions. Finally, the main operation modes of SIMS instruments are described in conjunction with examples of SIMS applications with complicating factors and practical problems that are encountered.

This chapter presents characterization techniques to study the electrical properties of semiconductors. For electrical measurements, a good metal–semiconductor contact is typically required. Therefore, in the beginning a short introduction to the physics of metal–semiconductor contacts is done, where special attention is paid to the difference and physical properties of Schottky and Ohmic contacts. Then follows the basics of resistivity and Hall effect measurements, after which capacitance–voltage characteristics are described, including deep level transient spectroscopy, which reveals very low concentration of defects and impurities at interfaces and in semiconductor layers. The chapter takes also into consideration the advantages, or disadvantages, with different electrical characterization techniques, as well as limitations for each characterization technique when applying electrical techniques for analysis of nanoscale materials and devices.