1.1 The journey of i.c.technology from micro (1959) to nano (2009

The Journey of I.C.Technology from micro (1959) to nano (2009) era.-Part 1.

Keywords: Solid State Technology, PhotoVoltaic Cell, Cat’s Whisker, Single Crystal Silicon;

Summary: This is Part 1 of the main lecture on 50 years IC journey.

INTRODUCTION

Einstein had once remarked “ We stand on the shoulders of Giants”.

The experiences of the Savage Age laid the foundation of the Barbarian Age. The experiences of Barbarians laid the foundation of Agricultural Civilization. The Guild Houses of the Agricultural Society and the Maritime Traders with their mercantile capital paved the way for the Industrial Society. So to understand and appreciate the Integrated Circuit (IC) Technology evolution we must go to 18 ^th century during the renaissance sweeping the Western World. Table I.1 (Appendix I ) gives the road map of development of Solid State Technology , Table I.2 (Appendix I) gives the road map of development of Electronics and Integrated Circuit Technology and Table I.3 gives the development in Super Computers.

In early eighteenth century, metal as a conductor and its positive temperature coefficient of resistance was recognized. This was followed by the discovery of a class of solids which exhibited negative temperature coefficient of resistance. The passage of current caused thermal runaway increase in current. This gave birth to Semi-Conductors. Contact potential between dissimilar materials was observed. In a series of experiments photo-voltaic effects in Ag-AgCl interface and light dependent resistance in Selenium was observed. This was followed by the construction of PV-cell and point contact diode. Point contact diode was fabricated by pressing a wire-point on Galena(PbS). This was also known as cat’s whisker. The cat’s whisker replaced the coherer in Radio Receivers. J.C. Bose patented cat’s whisker diode and AT&T patented a Silicon Crystal diode. By early 20 ^th century point contact diode was widely used as diode peak detector in Radios. This point contact diode was replaced by Vacuum tube Diode. CuO-Se was developed as PV Cell.

In 1930 the theoretical basis for Solid State Technology was laid with the publication of “ Quantum Theory meets Semiconductors” by Alan F. Wilson. This book contained the Band Theory of Solids, thermal generation of electron-hole pairs and the concept of intrinsic and extrinsic semi-conductor. Solid State Processing led to the preparation of Electronic Grade Polycrystalline Silicon.

At the end of 1947, point contact Ge- Transistor was invented which behaved like pentodes by Shockley , Bardeen and Braittain. Its power gain was tested by building an oscillator. But point contact Ge-Transistor were unstable, unreliable and became non-functional above 75ºC. Hence a transition was made to single crystal diffused Silicon Transistor.

The first npn BJT made of pure single crystal Silicon at BELL Labs by rate growing technique (made by Morris Tanenbaum and announced at June 1954 IRE Solid State Device Research Conference. The same paper was published in peer reviewed Journal of Applied Physics in June 1955).