The Story of Semiconductors

WHAT EVEN ARE SEMICONDUCTORS?

Semiconductors are a class of materials that have a level of conductivity between conductors and insulators, hence the name. They form the core of most modern electronics, including transistors which are powering the device you’re looking at this article on.

HOW WERE THEY INVENTED?

This is an interesting story that I came across in a book called The Disappearing Spoon.

The modern semiconductor was first built in 1945 at the prestigious Bell Labs in the US. A man named William Shockley was trying to build a silicon amplifier to replace the vacuum tube in computers. Vacuum tubes were fragile, hard to work with and prone to overheating. Even though the vacuum tubes were incredibly annoying, engineers needed them in computers because nothing else could do the double job of amplifying weak electronic signals, and working as a diode, a one way valve for electricity to pass through. 

Although Shockley had figured semiconductors were the way forward, after 2 years of work he dumped the project onto two younger scientists, John Bardeen and Walter Brattain.

Bardeen and Brattain set to work. They immediately decided that Silicon was far to brittle and hard to purify to make an amplifier. They decided to use the element below Silicon in the periodic table, Germanium. They finished building the world’s first solid state amplifier, from germanium, in 1947. 

Shockley, who was in Paris at the time saw the discovery and his jealousy grew. He quickly rushed back to Bell Labs to wedge himself into the world of transistor technology. When pictures were taken, Shockley pushed himself between Bardeen and Brattain. Later, he fired Bardeen to take over work on the transistor. Brattain later quit the job in anger over Bardeen’s firing. 

SO, WHY DO WE HAVE SILICON AND NOT GERMANIUM SEMICONDUCTORS TODAY?

As the semiconductor industry boomed, engineers worked feverishly to develop silicon semiconductors. Why? Even though germanium conducts electricity better than silicon, it also generates unwanted heat which caused germanium semiconductors to stall and overheat. More importantly, silicon is the second most common element on earth behind oxygen; it’s incredibly cheap.

At a semiconductor conference that same year while scientists were discussing the infeasibility of silicon semiconductors, a cheeky lad from Texas Instruments stood up and announced to the crowd that he had a working silicon transistor in his pocket.

He then gave the crowd an incredible demonstration of it’s power. He took out a germanium transistor, wired it to a record player and turned it on. Whith the music still playing, he lowered the record player into a vat of boiling oil.

As expected, the germanium transistor overheated and spluttered out. He then replaced the transistor with the silicon one from his pocket. This time when he lowered the record player into the boiling oil, the music continued playing.

IN THE END, BARDEEN, BRATTAIN AND SHOCKLEY ALL WON THE NOBEL PRIZE IN 1956 FOR THEIR CONTRIBUTIONS

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