ESD: Physics and Devices / Edition 1 available in Hardcover
ESD: Physics and Devices / Edition 1
- ISBN-10:
- 0470847530
- ISBN-13:
- 9780470847534
- Pub. Date:
- 10/29/2004
- Publisher:
- Wiley
ESD: Physics and Devices / Edition 1
Hardcover
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$197.95Overview
- Provides a clear understanding of ESD device physics and the fundamentals of ESD phenomena.
- Analyses the behaviour of semiconductor devices under ESD conditions.
- Addresses the growing awareness of the problems resulting from ESD phenomena in advanced integrated circuits.
- Covers ESD testing, failure criteria and scaling theory for CMOS, SOI (silicon on insulator), BiCMOS and BiCMOS SiGe (Silicon Germanium) technologies for the first time.
- Discusses the design and development implications of ESD in semiconductor technologies.
An invaluable reference for EMC non-specialist engineers and researchers working in the fields of IC and transistor design. Also, suitable for researchers and advanced students in the fields of device/circuit modelling and semiconductor reliability.
Product Details
| ISBN-13: | 9780470847534 |
|---|---|
| Publisher: | Wiley |
| Publication date: | 10/29/2004 |
| Pages: | 420 |
| Product dimensions: | 6.90(w) x 9.90(h) x 1.22(d) |
About the Author
Read an Excerpt
ESD Physics and Devices
By Steven Howard Voldman
John Wiley & Sons
Copyright © 2004 John Wiley & Sons, LtdAll right reserved.
ISBN: 0-470-84753-0
Chapter One
Electrostatics and Electrothermal Physics
1.1 INTRODUCTION
The discovery of electrostatic attraction and electrostatic discharge (ESD) is one of the earliest examples of the understanding of scientific thought and analysis. It goes back to the early foundations of the problem of the nature of matter, astronomy, mathematics and philosophy, and predates understanding of the nature of matter.
Thales of Miletus (624-546 B.C.E) was the founder of the Ionian (or Milesian) school and one of the Seven Wise Men of Ancient Greece in the pre-Socratic era. Thales was an astronomer, mathematician, and philosopher. He was an inventor and an engineer. Thales established a heritage of searching for knowledge for knowledge's sake, development of the scientific method, establishment of practical methods, and application of a conjectural approach to questions of natural phenomena. The Milesian School is regarded as establishing the critical method of philosophy of questioning, debate, explanation, justification and criticism. Students of Thales included Euclid, Pythagoras and Eudemus.
It was Thales of Miletus who was credited with the discovery of the electrostatic attraction. Thales noted that, after amber was rubbed, straw was attracted to the piece ofamber. It was from this event that, the Greek word for amber, [epsilon][lambda][epsilon][kappa][tau][rho]ov (electron) became associated with electrical phenomena. Knowledge of Thales' ideas was common through the writings of his disciples and Greek philosophers. Aristotle stated 'Some think that the soul pervades the whole universe, whence perhaps came Thales' view that everything is full of gods.'
Investigation of electrostatic phenomena predated early thoughts on the nature of physical matter. Thales's ESD experiments and study of electrostatic attraction occurred before the Greek atomistic schools of Democritus (420 B.C.E.), and Epicurus (370 B.C.E.), and the Roman school of Lucretius (50 B.C.E). Thales died before the schools of atomic thought were active. His tomb was inscribed 'Here in a narrow tomb Great Thales lies; Yet his renown for wisdom reached the skies.'
Robert A. Millikan, in the Introduction of his 1917 edition of The Electron stated:
Perhaps it is merely a coincidence that the man who first noticed rubbing of amber would induce in it a new and remarkable state now known as the state of electrification was also the man who first gave expression to the conviction that there must be some great unifying principle which links together all phenomena and is capable of making them rationally intelligible; that behind all the apparent variety and change of things there is some primordial element, out of which all things are made and the search for which must be the ultimate aim of all natural science. Yet if this be merely coincidence, at any rate to Thales of Miletus must belong a double honor. For he first correctly conceived and correctly stated, as far back as 600 B.C., the spirit which has actually guided the development of physics in all ages, and he also first described, though in a crude and imperfect way, the very phenomenon the study of which has already linked together several of the erstwhile isolated departments of physics, such as radiant heat, light, magnetism, and electricity, and has very recently brought us nearer to the primordial element than we have ever been before.
J. H. Jeans, in the 1925 fifth edition of The Mathematical Theory of Electricity and Magnetism, wrote: 'The fact that a piece of amber, on being rubbed, attracted to itself other small bodies, was known to the Greeks, the discovery of this fact being attributed to Thales of Miletus.' This fact, and the discovery of magnetism from lodestone, formed the 'basis from which the modern science of Electromagnetism has grown.'
With the death of Thales of Miletus, little progress was made on ESD phenomena. Although history moved forward, the advancement of triboelectric charging and electrostatic discharge phenomenon was slow. Europe saw the Roman Empire, the Golden Age of Islam, the Middle Ages, the Black Death, the Renaissance, the Reformation, and the advancement of nation states. ESD was discovered by Thales while China was under the Zhou Dynasty. Asia experienced tremendous changes, through the Qin, Han, Sui, Tang, and Song, Yuan, and Ming dynastic periods, but with no advancement of this field of knowledge.
With all this social change, there was insignificant growth in the understanding of electrostatic phenomenon until the 18th century. Interest in tribocharging and electrostatic phenomena became a hobby of scientists supported by the courts of Europe and laboratories of France and England. Gilbert, in the 17th century, noted that interaction between a glass rod and silk produced the same phenomenon discussed by Thales of Miletus; materials when rubbed with silk became 'amberized'. Gilbert began construction of the earliest list of triboelectrification.
In the same period, Stephen Gray (1696-1736) thought of the concept of dividing of materials according to their nature of removing or sustaining electrification. He defined a class of materials which remove 'amberization' as conductors, and the class of materials which allowed a body to retain its electrification as nonconductors, or insulators.
This work was followed by French physicist Dufay in 1733 discovering that the same effect can be achieved with sealing wax and cat's fur, and noting the effect was different from that of a glass rod. Dufay first noted that there was an attractive and repulsive phenomenon between different materials, naming the opposite processes as 'vitreous' and 'resinous.'
Benjamin Franklin, the first American ESD engineer, in 1747, also identified two processes, which he divided into 'positive' and 'negative' processes. The 'positive' process was the first process, discovered by Gilbert, that a physical body was electrified positive if repelled by a glass rod which had been rubbed with silk. The 'negative' process is any body repelled from sealing wax which had been rubbed with cat's fur, extending the work of Dufay.
In this time frame, many electrostatic scientists began recording the relationship of one body to another in the electrification process. Lists of materials were made to construct the early triboelectrification chart:
Cat's skin, Glass, Ivory, Silk, Rock Crystal, The Hand, Wood, Sulphur, Flannel, Cotton, Shellac, Caoutchouc, Resins, Guttapercha, Metals, and Guncotton
Around this time, some electrostatic scientists and engineers explored phenomena around them, investigating ESD phenomena of garments, and possibly influencing the 'human body model'. Robert Symmer (1759) conducted experimental studies in the dark, exploring the electrical discharge phenomenon on removal of his stockings and the interactions of two different sets of stockings, placing two white stockings in one hand and two black stockings in the other. In contrast, Coulomb developed the torsion balance in 1785, beginning the serious process of the understanding of the relationship of force, charge and physical distance. The experiments of Coulomb had been performed by Cavendish at an earlier date, but not published until 1879 by Maxwell.
At this time, the relationship of positive and negative electrification were not fully understood. In 1837, Michael Faraday performed the 'ice-pail experiment' involving a glass rod and silk which showed that 'positive and negative electrical charges always appear simultaneously and in exactly equal amounts.' Faraday, in his lecture Forces of Matter: Lecture V Magnetism-Electricity provided demonstrations of electrostatic charging phenomena, demonstrating the relationship of positive and negative charging effects. He would close his lecture on electrical phenomena with 'This, then is sufficient, in the outset to give you an idea of the nature of the force which we call ELECTRICITY. There is no end to the things from which you can evolve this power.'
Even at this time frame, the understanding of the relationship of matter, electrical charging and electrical force were not well understood. Different models were proposed, including single electrical fluid models, and two-fluid models, to explain the charging process. Models were established to explain these phenomena as related to a stress or strain of the medium, moving from an atomistic perspective to a field representation. It was at this time frame that Faraday and James Clerk Maxwell began addressing the understanding of electricity and electrical forces in terms of a field perspective and electrical charge was viewed as a "state of strain in the ether." James Clerk Maxwell, in Electricity and Magnetism in 1873, created the formulation of electricity and magnetism as we understand it today.
In 1889, Paschen began analysis of the breakdown phenomenon in gases, trying to explain the relationship of breakdown in gases by relating gas pressure and electrode spacing. Breakdown phenomenon in media took a great leap forward, influencing ESD understanding in today's devices.
In 1891, the word 'electron' as a natural unit of electricity was suggested by Dr G. Johnstone Stoney, connecting the ideas of Faraday's Law of Electrolysis. At this time, the understanding of the connection to physical matter was not understood, but it was used as a measure or unit. Johnstone Stoney reconnected the idea to the Greek word for amber, relating the early work of Thales of Miletus to the modern concept of an electrical unit, later to be shown to be connected to the structure matter and atomic theory.
From this brief history, it can be seen that electrostatic attraction predates the earliest thoughts on the understanding of matter. From 600 B.C.E to even as late as the 1890s the relationship of the discovery of Thales of Miletus were not understood as connected to the transfer of electrons.
Modern physics opened the door to the understanding of the atom and the relationship to electrical charge. It is too vast an undertaking to begin this book with a discussion of modern physics and the evolution of the electrical engineering discipline.
The electrical engineering profession has been compartmentalized into different fields, disciplines and sub-disciplines. It was the microelectronic industry that has led to a return of interest in electrostatic discharge phenomena. In the last 25 years, with the growth of the semiconductor industry, ESD has been a discipline of significant interest. In the 1970s as a result of the concerns in the Cold War of electromagnetic pulses (EMP) excellent physical models were being produced to understand the ESD robustness of electrical components. In the 1980s with the growth of semiconductor fabrication and the semiconductor industry, ESD issues remained an issue as human handling, tooling, shipping and garments, influenced the reliability of semiconductor components. Although ESD concerns existed, the resources and growth was limited in the 1980s, leading to a primitive understanding of how to avoid failure mechanisms, and how to design ESD robust semiconductor processes, devices and circuits. In the 1990s, there has been tremendous growth in ESD understanding, but new fields and new issues continue to emerge. As we make the transition from microelectronics to nanostructures, all types of components, from semiconductors, magnetic recording devices, micromachines, to photomasks have a larger concern with ESD.
Electrostatic discharge is a cross-discipline, bridging thermal, mechanical, and electrical physics. A difficulty in its teaching is that it also spans physical scales from the microscopic to macroscopic. The discipline involves understanding from the atomic surfaces, to nanostructure devices, to circuits, and systems. It spans both space and time. In time, it spans a wide timescale, from picosecond phenomenon to steady state. This is the modern difficulty of understanding of quantification and prediction as it spans disciplines, physical scales, temporal scales, and modeling representation. To conquer this, we will rebuild our understanding and the focus will be on physical models which will progress to practical examples.
1.2 A TIME CONSTANT APPROACH
1.2.1 ESD Time Constants
To understand physical phenomena, and particularly ESD phenomenon, it is necessary to quantify the scale in both space and time. ESD phenomena involve microscopic to macroscopic scales. ESD phenomena involve electrical and thermal transport on the scale of nanometers, circuits and electronics on the scale of micrometers, semiconductor chip designs on the scale of millimeters, and systems on the scale of meters. The time scales of interest range from picoseconds to microseconds. Electrical currents of interest range from milliamps to tens of amperes. Voltages range of interest vary from volts to kilovolts. Temperatures vary from room temperature to melting temperatures of thousands of degrees Kelvin. It is the vast ranges of time, space, currents, voltages, and temperature as well as its transition from the microscopic to the macroscopic which makes ESD difficult to model, simulate, and quantify.
To comprehend ESD phenomena, and establish validity of analytical developments, it is important to be able understand what phenomenon is important. By analyzing the physical equations from a time constant approach, equations and understanding can be made rigorous, as well as improving logical clarity. In such a fashion, electrical and thermal phenomena can be understood. By familiarity with the important time constants of interest, our understanding as well as insight will be better served. It is through this process that one can establish a higher intuition in this complex field.
1.2.1.1 ESD events
To understand the role of ESD events and the physical environments, it is important to quantify the characteristic times of an ESD event. ESD events are represented as circuit equivalent models.
1.2.1.2 Human body model characteristic time
A fundamental model used in the ESD industry is known as the human body model (HBM) pulse. The model was intended to represent the interaction the electrical discharge from a human being, who is charged, with a component, or object. The model (Figure 1.1) assumes that the human being is the initial condition. The charged source then touches a component or object through a finger. The physical contact between the charged human being and the component or object allows for current transfer between the human being and the object. A characteristic time of the human body model is associated with the electrical components used to emulate the human being. In the HBM standard, the circuit component to simulate the charged human being is a 100 pF capacitor in series with a 1500[ohm] resistor.
Continues...
Excerpted from ESD Physics and Devices by Steven Howard Voldman Copyright © 2004 by John Wiley & Sons, Ltd. Excerpted by permission.
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Table of Contents
About the Author.Preface.
Acknowledgements.
1. Electrostatics and Electrothermal Physics.
2. Electrothermal and Methods of Analysis ESD Models.
3. Semiconductor Device Physics and ESD.
4. Substrates and ESD.
5. Wells and Sub-collectors and ESD.
6. Isolation Technology and ESD.
7. Drain Engineering, Salicides and ESD.
8. Dielectrics and ESD.
9. Interconnects and ESD.
10. Silicon on Insulator (SOI) and ESD.
11. Silicon-Germanium and ESD.
12. Nanostructures and ESD.
Index.