The very first transistor that was invented used germanium for the semiconductor material. This suffered from a number of disadvantages, and many sought to make transistors using silicon.
If a silicon transistor could be made and perfected the performance could be improved, and production costs reduced.
The invention of the first silicon transistor is an interesting story, that has an element of theatrical performance about it, but nevertheless the invention of the first silicon transistor was a major leap forward for semiconductor technology.
The need for the first silicon transistors
Silicon offered the possibility of much greater the possibility of better performance, especially in switching circuits. Germanium transistors were relatively leaky and this mean that they did not turn fully off as well as a silicon one might - they could have very noticeable levels of current even when they are supposedly turned off.
Another issue was that germanium transistors had an issue that as they heated up as they carried current, this released more carriers to carry more current. If the circuit was not designed to prohibit this, then an issue known as thermal runaway could occur and the transistor would be destroyed.
Designing circuits to overcome thermal runaway often placed limitations on the performance.
Accordingly a silicon transistor could resolve these issues, but there were difficulties in fabricating silicon transistors at the time.
Silicon had a much higher melting point than germanium and it was more reactive. This meant that silicon was much more difficult to work than germanium. A good method of refining the silicon was also needed. For silicon transistors to work, it was necessary to be able to have a much higher level of purity, i.e. with less impurities in the crystal than could be obtained with methods of the time.
Work starts on the silicon transistor invention
A researcher named Gordon Teal was investigating the methods of refining semiconductors. Initially he was employed by Bell Labs, and had started to investigate the refining of silicon.
It had taken several years to produce sufficiently refined germanium for the first transistor, but the greater melting temperature combined with its reactivity meant that it had not been possible to produce sufficiently high grade silicon for transistors.
Teal was enticed to move over to a little know company called Texas Instruments. Here he continued his work on refining silicon.
The work undertaken by Gordon Teal succeeded in making sufficiently high grade silicon, and he started to make working silicon transistors.
On 14th April 1954, Gordon Teal demonstrated the first working silicon transistor to Pat Haggarty, a Vice President of Texas Instruments.
Haggarty knew that if they were able to successfully manufacture silicon transistors, this small and little known company would be ahead of all the others and become one of the leading semiconductor companies, if not the leader.
As a result they started manufacturing the first of these new silicon transistors.
First silicon transistor revealed at semiconductor conference
The launch of the first silicon transistor had a great deal of theatre about it, and it was to take the rest of the industry totally by surprise.
The Institute of Radio Engineers in the USA held a semiconductor conference in May 1954. At the conference a number of speakers discussed the difficulties of using germanium transistors and the possibility of overcoming these by using silicon.
However during various sessions at the conference, a number of speakers stated that silicon transistors were many years away from becoming a reality. They outlined the difficulties with refining the silicon to the degree to make the first silicon transistors.
To their surprise Gordon Teal from the little known Texas Instruments, produced a working silicon device. When he stood up to give his talk he opened it by saying:
Contrary to what my colleagues have told you about the bleak prospects for silicon transistors, I happen to have a few of them in my pocket.
At this, he stunned his audience and immediately put Texas Instruments firmly on the map and ahead of the competition.
What's more he was able to state that they had already started manufacture and devices were available.
This was a major advance, giving Texas a significant lead in transistor technology and making them a major semiconductor manufacturer. It took the other manufacturers several years to introduce their own varieties of silicon device.
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