Preface

**Section 5**

Memory *by Karim Ali*

**II**

*by Sung Min Park*

*by Saeed Mian Qaisar*

The Applications of Microchips **127**

**Chapter 7 129**

**Chapter 8 151**

**Chapter 9 173**

CMOS Integrated Circuits for Various Optical Applications

Area-Efficient Spin-Orbit Torque Magnetic Random-Access

Computationally Efficient Hybrid Interpolation and Baseline

Restoration of the Brain-PET Pulses

With the world marching inexorably towards the fourth industrial revolution (IR 4.0), one is now embracing lives with artificial intelligence (AI), the Internet of Things (IoTs), virtual reality (VR) and 5G technology. Wherever we are, whatever we are doing, there are electronic devices that we rely indispensably on. While some of these technologies, such as those fueled with smart, autonomous systems, are seemingly precocious; others have existed for quite a while. These devices range from simple home appliances, entertainment media to complex aeronautical instruments. Clearly, the daily lives of mankind today are interwoven seamlessly with electronics.

Surprising as it may seem, the cornerstone that empowers these electronic devices is nothing more than a mere diminutive semiconductor cube block. More colloquially referred to as the Very-Large-Scale-Integration (VLSI) chip or an integrated circuit (IC) chip or simply a microchip, this semiconductor cube block, approximately the size of a grain of rice, is composed of millions to billions of transistors. The transistors are interconnected in such a way that allows electrical circuitries for certain applications to be realized. Some of these chips serve specific permanent applications and are known as Application Specific Integrated Circuits (ASICS); while others are computing processors that can be programmed for diverse applications. The computer processor, together with its supporting hardware and user interfaces, is known as an embedded system.

In this book, a variety of topics related to microchips are extensively illustrated. The topics encompass the physics of operation of the microchip device, as well as its design methods and applications.

Chapter 1 presents an overview of microchips. In order to allow readers to appreciate the efforts researchers have sacrificed to arrive at the cutting-edge technology that we savor today, the historical development of microchips and its fundamental building block, i.e. the transistor, is first illustrated. This is then followed by a brief explanation of Moore's law – the law that governs the technological progression of microchips. A brief introduction to the field effect transistor – particularly the MOSFET, its operational principle, and the precipitating factors that necessitate the evolution of the planar MOSFETs to the three-dimensional FinFETs is also covered. At the end of the chapter, a walkthrough of the chip fabrication process is succinctly described.

In Chapter 2, an overview of the main challenges and design techniques for ultralow voltage and low-power analog integrated circuits in nanoscale technologies is illustrated. New design challenges and limitations linked to achieving low voltage operation, low process fluctuation, low device mismatch, and other effects are discussed. In the later part of the chapter, conventional and unconventional design techniques (bulk-driven approach, floating-gate, dynamic threshold, etc.) to design analog integrated circuits towards ultra-low voltage systems and applications are described. Examples of ultra-low voltage analog microchip blocks (such as an

operational amplifier, a voltage comparator, a charge pump, etc.) designed in a standard CMOS technology but with an unconventional design approach, are also given.

Chapter 3 describes the recent progresses in the tunnel field effect transistors based on 2-D TMD van-der-Waals heterostructure. The chapter covers the theoretical and computational efforts to understand the working mechanism and the limiting factors in these devices. It also sheds light on the design challenges to be addressed for the development of efficient tunnel field-effect transistors based on 2-D material van-der-Waals heterostructures.

In order to support and promote low-cost and bio-degradable electronics, organic field effect transistors (OFETs) have been introduced. Chapters 4 to 6 present a detailed elaboration on various topics related to OFETs. Since multiple crystalline packing states (crystal polymorphism) exist in the active layer of OFETs, a review on crystal polymorph control is given in Chapter 4. One way to minimize the threshold voltage of an OFET is to reduce the gate dielectric thickness. Chapter 5 discusses some of the most promising strategies towards high capacitance dielectrics for low voltage OFETs. Since OFETs are capable of providing tissue equivalent response to ionizing radiation, Chapter 6 presents the possibility of using different types of OFETs as ionizing and X-ray radiation dosimeters in medical applications.

Chapters 7 to 9 describe some of the recent applications of microchips. Chapter 7 presents several CMOS microchips realized for various optical applications, such as high-definition multimedia interface (HDMI), light detection and ranging (LiDAR), and gigabit Ethernet (GbE). Chapter 8 explains spin-orbit torque magnetic random-access memory (SOT-MRAM) and how it is used to realize reliable, high speed, and energy-efficient on-chip memory. Both non-diode-based SOT-MRAM and diode-based SOT-MRAM cells are discussed in this chapter. The final chapter, Chapter 9, describes the design of a novel offset compensated digital baseline restorer (BLR) and a hybrid interpolator. The behavior of the devices is configured using Very High-Speed Integrated Circuits Hardware Description Language (VHDL) and validated on a Field Programmable Gate Array (FPGA).

> **Kim Ho Yeap** Associate Professor, Department of Electronic Engineering, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Malaysia

### **Jonathan Javier Sayago Hoyos**

Section 1

Introduction to

Microchips

Postdoctoral Researcher, Instituto de Energías Renovables, Universidad Nacional Autónoma de México, México Section 1

Introduction to Microchips

**3**

process.

**2. A brief history**

**Chapter 1**

**1. Introduction**

Circuit Chip

Introductory Chapter: Integrated

*Kim Ho Yeap, Muammar Mohamad Isa and Siu Hong Loh*

The technological advancement of integrated circuit chips (or colloquially referred to as an IC, a chip, or a microchip) has progressed in leaps and bounds. In the span of less than half a century, the number of transistors that can be fabricated in a chip and the speed of which have increased close to 500 and 5000 times, respectively. Back in the old days, about five decades ago, the number of transistors found in a chip was, even at its highest count, less than 5000. Take, for example, the first and second commercial microprocessors developed in 1971 and 1972. Fabricated in the largescale integration (LSI) era, the Intel 4004 4-bit microprocessor comprised merely 2300 transistors and operated with a maximum clock rate of 740 kHz. Similarly, the Intel 8008 8-bit microprocessor released immediately a year later after its 4-bit counterpart comprised merely 3500 transistors in it and operated with a 800 kHz maximum clock rate. Both these two microprocessors were developed using transistors with 10 μm feature size. Today, the number of transistors in a very large-scale integration (VLSI) (or some prefer to call it the giant large-scale integration [GLSI]) chip can possibly reach 10 billion, with a feature size less than 10 nm and a clock rate of about 5 GHz. In April 2019, two of the world's largest semiconductor foundries— Taiwan Semiconductor Manufacturing Company Limited (TSMC) and Samsung Foundry—announced their success in reaching the 5 nm technology node, propelling the miniaturization of transistors one step further to an all new bleeding edge [1]. According to the announcement made in the IEEE International Electron Devices Meeting in San Francisco, the TSMC's 5 nm chip would be produced in high volume in the first half of 2020 [2, 3]. TSMC has also started work on their 3 nm nodes [3]. There is little doubt that the electronics world has experienced a quantum leap in its technology for the past 50 years or so and this, to a large extent, is due to the rapid improvement in the performance, power, area, cost and "time to market" of an IC chip. This chapter provides a succinct illustration on the historical evolution of the IC chip, a general overview of the fundamental building block of the chip—the field-effect transistors, and a brief description of the IC design

The thermionic triode was regarded as the predecessor of transistors that are prevalently used to build electronic devices today. Being invented in 1907, the triodes were made of vacuum tubes which were relatively large in size and were naturally cumbersome to be used. In December 1947, however, three physicists working in the AT&T Bell Laboratories— Dr. Walter Houser Brattain, Dr. John Bardeen and Dr. William Bradford Shockley, Jr.—achieved a remarkable scientific

### **Chapter 1**
