Preface

At the beginning of the 20st century, silicon “metal” was used as an alloying element for steels with electrical properties. The year 1906 saw the first application of crystalline silicon as a component of electromagnetic wave detection circuits in radio receivers, competing with galena.

Research carried out during the Second World War on silicon and germanium, the materials used in the components (point-contact diodes) of radar receiver circuits for aircraft detection and tracking, revealed that these materials are semiconductors whose basic characteristic is the control of electrical conductivity through doping. This characteristic prompted the search, after the Second World War, for solid components to replace “triodes” (vacuum tubes). This quickly led to the invention of the transistor.

The invention of the transistor is the founding act of the digital revolution (of the information society in which we live).

Germanium then silicon are the first two materials that enabled the invention of the transistor and the initial development of computers, while silicon dethroned germanium to produce the “MOSFET” (metal–oxide–semiconductor field-effect transistor), the basic component of integrated circuits: microprocessors and memories, the building blocks of computers.

But these components require materials (germanium and silicon) of extraordinary purity and perfect crystallinity. The purification of basic materials to purities of up to 11N, the production of single crystals of germanium, then silicon, the manufacture of components (based on transistors) and their miniaturization have posed problems of a complexity rarely encountered in the development of manufactured products.

These are the same properties and characteristics that have made silicon the material of choice for converting solar energy into electricity and for photographic sensors.

Silicon’s exceptional mechanical properties, combined with its electrical properties, make it the material of micro-electro-mechanical systems (MEMS), the key components of “intelligent objects”.

In 2018, there were no materials on the horizon that were likely to dethrone silicon as the material of choice for microelectronics and optoelectronics alike. According to Gérard Berry: “Silicon is not dead, far from it”.

This book is aimed at readers who want to know and understand how it was possible to go from the ENIAC computer, built during the Second World War, to calculate shell trajectories, 30 m long and 2 m high, with 17,468 triodes (vacuum tubes) and capable of executing 5,000 additions and subtractions in 1 s, to centimetric microprocessors with 20 billion transistors, processing power (number of instructions processed per second) of several gigahertz, making up the basic components of the individual computer, which is the size of a thin book.

To this end, this book, by tracing the history of discoveries, inventions, innovations and technological developments in materials, components, integrated circuits and memories, presenting the physical bases of their operation, and focusing on the materials and technologies used to make these components, attempts to answer the following questions:

• What specific properties (characteristics) – electrical, physicochemical, mechanical – are behind the successive dominance of silicon, then germanium, then silicon again in the development of microelectronics, the dominance of silicon in the conversion of solar energy into electricity, the dominance of silicon as the basic material for electromechanical microsystems?
• What properties (purity, crystallinity, doping) had to be imparted to the material, and how were they obtained to achieve the performance achieved by these components today?
• What processes had to be developed to produce these components, and then to meet the demands of miniaturization, enabling the high-speed data processing performance we are seeing today, efficient conversion of solar energy into electricity, etc.?
• Who were the architects of this epic? According to Gérard Berry1, “its extraordinary success (that of silicon) is clearly to the credit of semiconductor materials physicists, who made technological advances that required enormous imagination and skill to overcome all the obstacles”.

Until 1942, silicon extracted from silica (SiO2) and germanium extracted from sulfide (GeS2) were considered as metals. The semiconductors known at the time were chemical compounds: oxides (Cu2O) and sulfides (galena PbS), composed of a metal and a metalloid (oxygen or sulfur), whose basic characteristic was the increasing variation of their conductivity with temperature, whereas the conductivity of metals decreases with increasing temperature. It was not until the summer of 1942 that it was recognized that purified silicon and germanium were not metals, but semiconductors.

This book is divided into two volumes. Volume 1 is devoted to basic components (diodes and transistors).

Chapter 1 presents (1) the work that led to the extraction of silicon from silica and its purification and the discovery, extraction and purification of germanium; (2) the basic physical characteristics of semiconductors made from these two materials, knowledge of which is essential for understanding how components work.

Chapters 2–6 of Volume 1 present the basic components (diodes, transistors) in the chronological order of their discovery/invention, and the technological developments required for their realization.

Each chapter includes a presentation of the component, how it works and its basic functions, followed by the history of the research and development that led to its invention and production. The physical basis of its operation is presented in the appendicies of each chapter. The technologies used to satisfy the requirements of purity and crystalline perfection of the base material are presented chronologically, as are the technologies used to produce the components and the evolutions required by their miniaturization. The industrial development of the first components is presented according to their importance for subsequent developments.

Volume 2 is devoted to “chips, optoelectronic components and MEMS”.

Chapters 1 and 2 present microcomputer integrated circuits and memories.

Chapter 3 presents the silicon thin film transistor TFT, which led to the development of flat-panel liquid crystal displays.

Chapters 4 and 5 present silicon optoelectronic components. These include solar cells for converting solar energy into electricity and photoelectric image sensors for digital cameras, which have revolutionized astronomy and medical imaging.

Chapter 6 presents microelectromechanical systems (MEMS), the exceptional mechanical properties of silicon that have enabled their development, and the specific technologies developed for building structures with moving parts.

Many English and American books present the “history of semiconductors”. Compared with the reference works cited in the reference lists, this book presents not only the historical aspects, but also the recent technological developments that have enabled the current performance of microprocessors, memories, solar cells and electromechanical microsystems. The book is based on numerous works by historians and original publications.

The author would particularly like to thank Professors Jean Philibert and André Pineau.

References

1. Burgess, P.D. (n.d.). Transistor history [Online]. Available at: https://sites.google.com/site/transistorhistory.
2. Computer History Museum (n.d.). The silicon engine timeline [Online]. Available at: www.computerhistory.org.
3. Hu, C. (2009). Modern Semiconductor Devices for Integrated Circuits. Pearson, London.
4. Krakowiak, S. (2017). Éléments d’histoire de l’informatique. Working document, Université Grenoble Alpes & Aconit, CC-BY-NC-SA 3.0 FR.
5. Lazard, E. and Mounier-Kuhn, P. (2022). Histoire illustrée de l’informatique. EDP Sciences, Les Ulis.
6. Lilen, H. (2019). La belle histoire des révolutions numériques. De Boeck Supérieur, Louvain-la-Neuve.
7. Lojek, B. (2007). History of Semiconductor Engineering. Springer, New York.
8. Mathieu. H. (2009). Physique des semi-conducteurs et des composants électroniques, 6th edition. Dunod, Paris.
9. Nouet, P. (2015). Introduction to microelectronics technology. Working document, Polytech Montpellier, ERII4 M2 EEA Systèmes Microelectronics.
10. Orton, J.W. (2004). The Story of Semiconductors. Oxford University Press, Oxford.
11. Orton, J.W. (2009). Semiconductors and the Information Revolution: Magic Crystals that made IT Happen. Elsevier, Amsterdam.
12. Riordan, M. and Hoddeson, L. (1997). Crystal Fire: The Invention of the Transistor and the Birth of the Information Age. W.W. Norton & Company, New York.
13. Seitz, F. and Einspruch, N.G. (1998). Electronic Genie: The Tangled History of Silicon. University of Illinois Press, Illinois.
14. Sze, S.M. (2002). Semiconductor Devices: Physics and Technology. Wiley, New York.
15. Verroust, G. (1997). Histoire, épistémologie de l’informatique et révolution technologiques. Course summary, Université Paris VIII,...