Historical Note: The Development of the Transistor

It is a rare event in the history of civilization when a single invention is so powerful that it alters the course of human history. The invention of the Transistor is one of those events. It was the most important device ever invented that ultimately launched the digital revolution.

The transistor is a device that works as a switch and it is the building block of all what is digital. It is a technology based on material known as semiconductor where the flow of the electric current in such material could be controlled, allowing the transistor to amplify or switch its current. This is the fundamental and basic idea of how the transistor works. Today, your iphone has probably more than one billion transistors inside it with computing power more than the computing power of the entire world in 1950! How and why did we invent the transistor?

It all began with our desire to calculate numbers and solve mathematical formulas. Mechanical and electronic computing machines were developed in1830's and 1930's, respectively, where mechanical gears, electronic relays and vacuum tubes were used. Soon the benefits of switching and storing data were clearly established by the early computing pioneers. 

Given their slow and impractical size, mechanical parts gave way to magnetic relays, and due to their slow and inflexibility, magnetic replays gave way to vacuum tubes. But vacuum tubes were expensive, large, and suffered from low efficiency and high unreliability. So, the search within the scientific community for a better switching element other than the vacuum tube for computing purposes was in full swing in the 1930’s. 

History has shown time and again that every time we understood a force of nature, a fundamental technical shifts starts unraveling. The transistor discovery occurred only after we understood the internal forces of the atom in the early 20th Century, giving birth to new science known as Quantum Physics.

The use of solid state material to develop devices to replace the vacuum tube was in full gear in the late 1930's when the US was interested in ways to detect aircraft during the Second World War, by monitoring radio signals at high frequencies. Such a detection device later came to be known as the RADAR. The challenge they faced is that vacuum tubes didn't work well at these high frequencies. One of the many technology improvements made during the development of the radar was a solid-state device that can rectify high frequency signals, replacing the use of vacuum tube as a signal amplifier. Meantime, scientists at the Bell Labs in the USA discovered that that in semiconductor material, there are sufficient number of electrons that can be allow to flow to make it possible and precisely control current flow. 

Finally, the breakthrough came in December 1947 when three scientists at Bell Labs in the US, invented the solid-state Transistor, one of the greatest revolutionary invention, redirecting the history of mankind as the seed for the digital revolution has been planted. The inventors of the transistor were John Bardeen, Walter Brattain, and William Shockley, who in 1956, all shared the Nobel Prize in Physics.

Unlike mechanical, magnetic relays, and vacuum tube based computing, the failure rates of transistor-based computing was trivial. By 1950’s, traditional vacuum tube and its glass container, hot filament, a spark, or vacuum, and replacing it with a small solid state device almost ten times smaller. In a short time, computing is reborn, transistor computers replaced the relay and vacuum tubes based computers. Moreover, the invention of the transistor ushered in a new massive computing speeds never believed possible. Immediately after the transistor was invented, all electronics and computers were digital. The world has never been the same since.

Issa Batarseh

(The name transistor is derived from shortening the two words “transition resistor” since the resistance of the solid state material transitions from one level to another as the device operation changes.)