Invention of the Integrated Circuit: The IC History

The invention of the Integrated Circuit, IC by Jack Kilby and Robert Noyce was a major step in the development of modern electronics technology.

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Invention of the integrated circuit    

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The history of the integrated circuit is one of the most important stories within the electronics arena. It lead onto other developments like the invention of the microprocessor and more.

The invention of the integrated circuit arose out of the need for more reliable and easy methods for the manufacture of electronic equipment as well as the need for much smaller assemblies.

Although the inventors of the integrated circuit are generally accepted to be Jack Kilby and Robert Noyce, many other engineers and scientists were involved in supporting these inventions and setting in place the foundation stones. Indeed, there has long been discussion regarding who should be given the honour of being credited with the invention of the integrated circuit.

Foundations for the integrated circuit invention

With the transistor well established, people soon started to wonder if several electronic components could be placed on the same piece of semiconductor. If this could be accomplished then considerable improvements in performance and reliability would be obtained in addition to reductions in size.

One of the main driving forces in the history of the integrated circuit, IC came out of the need for improved military equipment. The Second World War had conclusively proved the value of electronics beyond all doubt. Radar had been an outstanding success, and many other new uses had been found for electronic equipment.

One of these was an early computer called Colossus which was developed by the British to help decipher German encrypted messages. It contained over 1500 valves or vacuum tubes and a host of other electronic components. It also generated a phenomenal amount of heat. It was the most complicated piece of electronic circuit design of the time and it proved to be phenomenally successful although somewhat unreliable.

As electronic equipment became more sophisticated and complicated a number of problems arose. Firstly the physical size grew. This was a particular disadvantage for aircraft where size and weight were very important. The sheer number of electronic components needed increased the weight of many electronic circuit designs and this limited the complexity of equipment which could be carried in aircraft.

The second disadvantage was even more important. As the complexity of the electronic circuit designs grew, so the reliability fell. It often fell to a point where it was being maintained for longer than it was in use. This was particularly true of some of the early valve / vacuum tube based computers.

Some of these problems were solved to a degree by the use of new construction techniques. Smaller valves enabled the size of equipment to be reduced a little, as did the introduction of printed circuit boards. However the main advantage brought about by the introduction of printed circuit boards was an increase in reliability.

Despite these improvements the basic problems were not solved. Reliability was still too low, and the equipment too large.

Then in 1948 the Soviet Union exploded its first nuclear bomb. The USA saw this as a great threat. It meant that the Soviet Union could easily launch an atomic attack on the USA. With existing technology the USA would not be able to detect this until it was too late. Better methods of detecting possible threats were needed, and this required more complicated electronics.

Tinkertoy sets foundations for IC invention

One of the first major attempts to solve the problems of size and reliability was started in 1951 when the U.S. Government funded a study. Code named Tinkertoy, it investigated a number of possibilities, many of which are in standard use today.

Within Tinkertoy, double sided and even multi-layer printed circuit boards were developed. Also techniques for making plated through holes on a printed circuit board were developed. Whilst the transistor may have seemed an obvious candidate for inclusion in the project, it was not used because the technology was very new and unreliable at the time.

Other developments and ideas laying the foundations for the invention of the integrated circuit were beginning to be set in place. Across the Atlantic in England, Dr G Drummer from the Royal Radar Establishment proposed the idea of building an electronic circuit design as a solid block without any interconnecting wires. However this was more of a vision of the future because there were no practical ideas to support it. Nevertheless it was a remarkably accurate prediction of what the future might hold.

A year later in May 1953 the first patent for an integrated circuit was filed by H Johnson working for the Radio Corporation of America (RCA). He proposed that all the electronic components for a phase shift oscillator could be contained on a single chip of silicon. He detailed how the individual electronic components could be made, but as the first PN junction transistors had only just been made the technology did not exist to be able to manufacture it.

Nevertheless Johnson was not credited as the person who invented the integrated circuit as it was only a concept and it could not be made at the time.

More steps towards IC invention

Meanwhile back in the UK, Drummer kept working on his idea. In 1957 he placed an order with the research wing of Plessey to investigate methods which could be used to manufacture an IC. This was a key development within the integrated circuit history.

It took some time for work on the project to start properly. In fact it was not until 1959 that work was really under way. Unfortunately, by this time it was too late because wok was progressing far more swiftly in the USA.

The invention of the IC required many elements to be in place: the transistor, silicon processing technology, ideas about printed circuit boards, and many more.

Tinkertoy moves on

By 1957 transistors were becoming far more widespread. They were beginning to find their way into more equipment. Even military equipment which tended to use tried and tested technologies was starting to become transistorised in some areas.

With this change it soon became apparent that transistors could give significant improvements in reliability and size reduction. This caused the US Government to update their Tinkertoy project to include various aspects of semiconductor technology.

Their work was split up so that a number of different companies progressed separately, but followed similar lines of research. One of the companies which had been awarded a contract was Texas Instruments. TI had been the first company to produce a silicon transistor, and one of the first to produce field effect transistors. It was to this company that a very gifted young engineer named Jack Kilby came about a year after the project had started. Jack Kilby was to become the person who invented the integrated circuit.

First integrated circuit invented

It was as a result of a quirk in the company bureaucracy that major advances were made. When Jack Kilby joined Texas Instruments he had very little leave entitlement. When the annual company shutdown occurred he offered to work there on his own. This gave him the opportunity to follow many of his own ideas through.

Kilby started by making a number of phase shift oscillators on a single chip of germanium. The circuit was simple but quite sufficient to be able to prove the feasibility of the technology.

During the shut-down Kilby made tremendous progress, first deciding the pattern to be made on the germanium substrate and then transferring these onto the semiconductor substrate. Then on 12th September 1958 he succeeded in making the first of his circuits work. Following on from this success he made a further batch to prove the repeatability of the process. Again he was successful and produced a high yield from the circuits he had made. Thie work meant that Jack Kilby was jointly honoured as being the inventor of the integrated circuit.

Another IC invention

As the US Government had a number of similar contracts with several companies, it was hardly surprising to find that they were reaching similar conclusions.

Robert Noyce, working for Fairchild reasoned that it was foolish to make a large number of transistors on a chip which was then cut up to give the individual devices. Typically transistors were manufactured by taking a wafer of silicon within which a large number of transistors would be manufactured. The wafer would then be cut to provide the individual transistors.

In the manufacture of equipment these devices were then assembled together. Instead Noyce thought it would be more sense to remove the splitting and reassembly stages. Noyce applied his knowledge of transistor production technology to lay the foundations of much of today's IC technology.

In view of their complementary work, Kilby and Noyce are jointly credited with the invention of the integrated circuit. The title inventor of the integrated circuit is given to Robert Noyce along with Jack Kilby.

More impetus for IC invention

Like many revolutionary ideals the IC was not an immediate success. The idea caught the imagination of many engineers and scientists but the reality of their high cost limited their use to a very small number of specialised applications.

It was not until 1961 that the first ICs were marketed. Even then only two companies: Texas and Fairchild were producing any, and at $120 (at 1961 prices) for a typical IC, it was hardly surprising their use was limited.

Then in 1961 President Kennedy announced his vision for space research saying that America would place a man on the moon by the end of the decade. For this to be achieved vast amounts of money had to be made available to develop the new technology needed. One of the prime areas for research was in electronics. Size weight and reliability were some of the prime requirements. As a result of this new impetus more ICs soon became available, although their cost was still very high.

Early development

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 USA. 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.

The integrated circuit quickly became accepted as a mainstream technology for the electronics industry. By the end of the 1960s both analogue and digital integrated circuits had become accessible for many different products. Their cost was reasonable and they started to be used in increasing quantities.

Digital or logic circuits became mainstream with the introduction of the first 74xx series of integrated circuits and analogue circuits like operational amplifiers as well as a number of RF integrated circuits were also in widespread use.

The joint inventors of the integrated circuit, Jack Kilby and Robert Noyce were able to see their invention become a major success.

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