Characterisation and Control of Defects in Semiconductors

Book Preface

to remove them by post-processing measures, such as thermal treatments. Even though many defect-related problems have been identified and solved over the past 60 years of semiconductor research, the constant quest for faster, cheaper, less-power consuming, and new kinds of electronics generates the need for new materials’ properties and creates new defect-related challenges.
The wide variety of methods used to identify and characterize defects in semiconductors can be roughly divided into electrical measurements, optical spectroscopy, particle beam methods, and electron microscopy. Theoretical calculations provide significant insights into the physical properties of the defects. The scientific literature contains a wide selection of detailed reviews on the various experimental and theoretical approaches to studying defects in semiconductors. In this book, the focus is on point defects since they are easily thermally (and kinetically) generated during manufacturing and abundantly introduced during post-manufacturing processing steps. All chapters follow a similar structure: the first part provides a tutorial-like presentation of a method or of a collection of methods, while the second part demonstrates the possibilities of the method by discussing various examples from the recent research on defects in semiconductors. Each chapter is concluded with a discussion on the potential future developments and new application areas of the reviewed method.
This book is composed in such a way that each of the 11 chapters, written by experts in the respective fields, can be read as a separate review on the technique it focuses on. For the benefit of a reader who wishes to get a more thorough overview of the field, the examples of defect studies discussed in the chapters focus around two themes of recent interest: acceptor-type defects in nitride semiconductors and oxygen vacancies in oxide semiconductors. Also, other semiconductor systems and defects are discussed, including those of interest for quantum computing in SiC, those of interest for thermoelectric and long-wavelength optoelectronics in narrow gap semiconductors, and many others. Chapters 1 and 2 focus on the characterization of the electrical and optical properties of the defects. Methods reviewed in these chapters include deep-level transient spectroscopy and other capacitance spectroscopic techniques as well as photoluminescence spectroscopy. Identifying the microscopic (atomic) structures of the defects is at the focus in Chapters 3–6. Vibrational spectroscopy and magnetic resonance techniques reviewed in Chapters 4 and 5 are based on the interactions of electromagnetic radiation (microwaves, infrared, visible light) with the ions and electrons in the semiconductor lattice. Chapters 5 and 6 review the use of “exotic” particles, namely, muons and positrons, in the identification and quantification of point defects in semiconductors. Chapter 7 concludes the discussion on the basic physical properties of defects by reviewing the state-of-the-art theoretical approaches used in the field. Chapter 8 reviews the various electron-microscopy techniques and their uses for imaging individual point defects and interactions between extended and point defects. Chapter 9 reviews a recent addition to the family of defect-characterization techniques: 3D atom probe tomography that augments the capabilities of secondary ion mass spectrometry. Chapters 10 and 11 conclude the book by reviewing ion-beam-based modification and char-acterization methods of semiconductors and their defects.