Electronics

from Classical to Quantum

Michael Olorunfunmi Kolawole

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9781000089066
• Edition: 1
• Topic: Tecnologia e ingegneria
• Subtopic: Ingegneria elettronica e telecomunicazioni

This book gives clear explanations of the technical aspects of electronics engineering from basic classical device formulations to the use of nanotechnology to develop efficient quantum electronic systems. As well as being up to date, this book provides a broader range of topics than found in many other electronics books. This book is written in a clear, accessible style and covers topics in a comprehensive manner.

This book's approach is strongly application-based with key mathematical techniques introduced, helpful examples used to illustrate the design procedures, and case studies provided where appropriate. By including the fundamentals as well as more advanced techniques, the author has produced an up-to-date reference that meets the requirements of electronics and communications students and professional engineers.

Features

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• Discusses formulation and classification of integrated circuits

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• Develops a hierarchical structure of functional logic blocks to build more complex digital logic circuits

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• Outlines the structure of transistors (bipolar, JFET, MOSFET or MOS, CMOS), their processing techniques, their arrangement forming logic gates and digital circuits, optimal pass transistor stages of buffered chain, sources and types of noise, and performance of designed circuits under noisy conditions

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• Explains data conversion processes, choice of the converter types, and inherent errors

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• Describes electronic properties of nanomaterials, the crystallites' size reduction effect, and the principles of nanoscale structure fabrication

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• Outlines the principles of quantum electronics leading to the development of lasers, masers, reversible quantum gates, and circuits and applications of quantum cells and fabrication methods, including self-assembly ( quantum -dot cellular automata ) and tunneling (superconducting circuits), and describes quantum error-correction techniques

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• Problems are provided at the end of each chapter to challenge the reader's understanding

1 Formulation and Classification of Electronic Devices

Circuits have been fundamental to the development of electronic devices: from the basic analog to integrated digital systems and to the evolving quantum computing systems. This chapter discusses the technological processes involved in producing electronic devices or circuits that comprise many layers of formation from basic single to compound elements. These elements include the type of chemical bonding involved (ionic or covalent) as well as the process of creating features in a specialized layer of material through chemical modification and how pattern transfer is carried out multiple times to form the device or circuit, and their limitations. The classification of ICs by integration levels is also discussed. An IC, also called chip, is an assembly of electronic components, fabricated as a single unit with miniature devices and their interconnections, built up on a thin substrate of semiconductor material(s).

1.1 Introduction

Circuits have been fundamental to the development of electronic devices. A circuit that allows continuous, variable signal is called an analog circuit. Analog circuits within electrical equipment have conveyed information through changes in the current, voltage, or frequency. An analog circuit can be used to convert the original continuous, variable signal into binary bits, usually expressed as “0” and “1”: synonymous, respectively, to “off” and “on.” (More is said about the conversion technique in Chapter 7.) A digital circuit operates on quantized binary bits: “0” or “1.” A basic quantum circuit, however, operates on a small number of signals, called qubits, which is the quantum version of the classical binary bit physically realized with a two-state device. In the classical logic circuits, behavior is governed implicitly by classical physics: no restrictions on copying or measuring signal, whereas the behavior of quantum circuits is governed by quantum mechanics. (More is said about classical logical circuits and quantum circuits in Chapter 2, Chapter 3, Chapter 4, Chapter 5 and Chapter 6 and 9, respectively.) Technically, all these circuits attempt to find circuit structures for needed operations that are functionally correct and independent of physical technology, and, wherever possible, that use the minimum number of components, logic gates, or quantum bits (qubits for short). Such development of circuit structures has led to miniaturized circuits of modern integrated circuit (IC) electronics. An IC is an electronic device that integrates (or gathers) a number of electronic components on a small semiconductor chip. Technically, an IC has a particular functionality. ICs’ electronics have evolved and continued to gain from continuous research. The research outcomes have led to improvements in IC characteristics and fabrication processes used.

1.2 Basic Properties of Semiconductors

Devices such as modern computer processors and semiconductor memories fall into a class known as ICs. They are so named because all of the components in the circuit (and their “wires”) are connected together and formed on the same substrate or wafer. An IC, also called chip, is an assembly of electronic components, fabricated as a single unit with miniature devices and their interconnections, built up on a thin substrate (or wafer) of semiconductor material(s).

Semiconductors are unique materials, usually a solid chemical element—such as silicon (Si), or compound—such as gallium arsenide (GaAs) or indium antimonide (InSb), which can conduct electricity or not under certain conditions. Semiconductor behavior is not restricted to solids: there are liquid conductors, for instance, mercury (Hg) and those regarded as “Type II alloys” superconductors. It should be noted that the resistivity of most metals increases with an increase in temperature and vice versa. As such, there are some metals and chemical compounds whose resistivity becomes zero when their temperature is brought near zero-degree Kelvin (0°K) (i.e. −273°C). {Note that absolute temperature, T, in degree Kelvin (°K), is expressed by = 273 + t, where t =measured temperature in degree Celsius.} At this stage such metals or compounds are said to have attained superconductivity. The transition from normal conductivity to superconductivity takes place almost suddenly over a very narrow range of temperature. Mercury, for example, becomes superconducting at approximately 4.5°K. Type-II superconductors usually exist in a mixed state of normal and superconducting regions [1]. However, because of atomic diffusion, regions with different dopings will mix rapidly and a stable device with an inhomogeneous structure is not possible [2].

Semiconductors can be made to conduct electricity by adding other impurity elements to the semiconductor material. However, areas of semiconductor material that are highly pure and with little or no impurities would impede the free flow of electrons from atom to atom (and molecule to molecule) and would act as insulators. When electrons flow freely, the semiconductor’s electrical conductivity lies in magnitude between that of a conductor and an insulator: specifically in the range of 10⁻³ to 10⁻⁸ S cm⁻¹ (Siemens per centimeter).

An atom is a form of matter that consists of a very small nucleus surrounded by orbiting electrons, as depicted in Figure 1.1. The nucleus is made up of a core of protons (positively charged particles) and neutrons (particles having no charge). Protons and neutrons are composite particles, each consisting of three quarks, and as such, they may not be considered as fundamental particles in the true sense of the term. Nevertheless, they are regarded as being fundamental particles for all chemical purposes.

FIGURE 1.1 Fundamental particles of an atom.

A proton’s charge distribution decays approximately exponentially. Electrons are arranged around the nucleus in energy levels. The total number of electrons in an atom is the same as the number of protons in the nucleus. When the number of protons in a nucleus equals the number of electrons orbiting the nucleus, the atom is electrically...