With the basic IC now in existence, the next stage of the story was in the integrated circuit development.
It had to develop from being a high cost laboratory experiment available for a few niche applications to one where it was available at low cost and for all the electronics arenas.
The development of the integrated circuit to its current state of widespread use took many years and much development.
However costs gradually fell, and usage steadily increased as more products were developed to take advantage of IC technology.
The early progress in the development of the IC was not easy. The high cost gave an indication of the difficulties which were being encountered. Yield was a major problem. Only a limited amount of accuracy was available with the processes available at the time, and this meant that only a small proportion of the chips worked correctly. The more complicated the chip, the smaller the chance of it working. Even circuits with a few tens of components gave yields of about only 10%.
Most of the IC development in the 1960s was devoted towards increasing the yield. It was recognised that the key to success in this field lay in being able to manufacture ICs economically. This could only be achieved if the percentage of working circuits in a wafer could be significantly increased.
Most of the development and advances were made in the USA because of the amount of money which was available for space research.
Despite this other countries made a number of significant advances. Europe was well up with the field. In the UK a lot of preparatory work had been undertaken by Plessey for the Royal Radar Establishment. Other companies including Ferranti, Standard Telephones and Cables (S.T.C.) and Mullard (now part of Philips, which in turn has changed to NXP) all joined the IC club. Other countries in Europe saw similar interest in these new devices.
Japan, which fast becoming a very major force in world economics saw the significance of semiconductor technology. In most areas of research from the first production transistors to IC technology itself they were only about two years behind the U.S.A.. One of the first Japanese companies to produce ICs was the Nippon Electric Company, NEC which brought its first products to market in 1965.
Realising the vast amounts of research which would be needed to gain a world leadership, five of the largest Japanese IC manufacturers cooperated on a joint research venture with the Government in 1975. This scheme paid enormous dividends placing some of these companies right at the top of the tables for IC sales.
New IC technologies developed
All the early work on IC technology had been undertaken using bipolar technology. Very soon it was found that heat dissipation was the greatest factor limiting the development of the size and complexity of ICs. With the number of components on an IC being packed into a very small area heat problems were many orders of magnitude worse than if the circuit had been built up using discrete components.
Initially, the work was concentrated on finding more efficient ways of removing the heat, but this only gave limited success. It soon became obvious that a more revolutionary approach was needed if integration levels were to rise.
The answer to the way forwards for the integrated circuit development came in the form of a new transistor technology. First manufactured in 1963 the field effect transistor had great advantages in that the gate consumed virtually no current. Also the channel had a relatively low "on" resistance and a high "off" resistance. This made it ideal for digital applications where the current consumption could be reduced by many orders of magnitude.
Texas Instruments were again leading the way and they were the first company to launch an MOS device onto the market in 1966. Their first device was a binary to decimal converter, but many others followed shortly afterwards.
Further integration levels
As MOS technology had largely conquered the problem of heat dissipation, the way lay open for the development of much higher levels of integration.
Progress in this area of integrated circuit development was very rapid. Only a year after Texas launched their first device, Fairchild took the lead by manufacturing a device with over a thousand transistors. The chip was a 256 bit RAM and it was the first major attempt at conquering the dominance of the magnetic core memory which was used in computers at this time.
While it was a milestone in semiconductor technology the device was not a commercial success. The chip was about twice as expensive as the traditional core memory and it did not sell. However it showed the way which semiconductor technology was to progress. Only when 1 kbit RAMs were launched did semiconductor devices start to show an advantage.
As the 1970s progressed MOS technology became the dominant format for ICs. Although linear ICs were gaining in popularity and chips like the famous 741 operational amplifier were introduced, it was MOS technology which dominated the market. Integration levels continued to increase and new ideas started to develop in the minds of IC designers
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