1907 - The Problem

AT&T brought its former president, Theodore Vail, out of retirement to help it fight off competition erupting from the expiration of Alexander Graham Bell's telephone patents. Vail's solution: transcontinental telephone service.

In 1906, the eccentric American inventor Lee De Forest developed a triode in a vacuum tube. It was a device that could amplify signals, including, it was hoped, signals on telephone lines as they were transferred across the country from one switch box to another. AT&T bought De Forest's patent and vastly improved the tube. It allowed the signal to be amplified regularly along the line, meaning that a telephone conversation could go on across any distance as long as there were amplifiers along the way.

But the vacuum tubes that made that amplification possible were extremely unreliable, used too much power and produced too much heat. In the 1930s, Bell Lab's director of research, Mervin Kelly, recognized that a better device was needed for the telephone business to continue to grow. He felt that the answer might lie in a strange class of materials called semiconductors.

1945 - The Solution

After the end of World War II, Kelly put together a team of scientists to develop a solid-state semiconductor switch to replace the problematic vacuum tube. The team would use some of the advances in semiconductor research during the war that had made radar possible. A young, brilliant theoretician, Bill Shockley, was selected as the team leader. (See Shockley, Brattain and Bardeen—the team and the teammates)  

Shockley drafted Bell Lab's Walter Brattain, an experimental physicist who could build or fix just about anything, and hired theoretical physicist John Bardeen from the University of Minnesota. Shockley filled out his team with an eclectic mix of physicists, chemists and engineers. The group was diverse, yet close knit. Walter Brown, a physicist who joined the group in 1951, recalls hearing about exuberant parties and good lunches. Betty Sparks, Shockley's secretary, recalled the group's high spirits at her wedding to Morgan Sparks. They called their lab "Hell's Bells Laboratory."

In the spring of 1945, Shockley designed what he hoped would be the first semiconductor amplifier, relying on something called the "field effect." His device was a small cylinder coated thinly with silicon, mounted close to a small, metal plate. It was, as University of Illinois Electrical Engineer Nick Holonyak said, a crazy idea. Indeed, the device didn't work, and Shockley assigned Bardeen and Brattain to find out why. According to author Joel Shurkin, the two largely worked unsupervised; Shockley spent most of his time working alone at home.

Ensconced in Bell Labs' Murray Hill facilities, Bardeen and Brattain began a great partnership. Bardeen, the theoretician, suggested experiments and interpreted the results, while Brattain built and ran the experiments. Technician Phil Foy recalls that as time went on with little success, tensions began to build within the lab group.

In the fall of 1947, author Lillian Hoddeson says, Brattain decided to try dunking the entire apparatus into a tub of water. Surprisingly, it worked... a little bit. 

Brattain began to experiment with gold on germanium, eliminating the liquid layer on the theory that it was slowing down the device. It didn't work, but the team kept experimenting using that design as a starting point. 

Shortly before Christmas, Bardeen had an historic insight. Everyone thought they knew how electrons behaved in crystals, but Bardeen discovered they were wrong. The electrons formed a barrier on the surface. His breakthrough was what they needed. Without telling Shockley about the changes they were making to the investigation, Bardeen and Brattain worked on. On December 16, 1947, they built the point-contact transistor, made from strips of gold foil on a plastic triangle, pushed down into contact with a slab of germanium.

When Bardeen and Brattain called Shockley to tell him of the invention, Shockley was both pleased at the group's results and furious that he had not been directly involved. He decided that to preserve his standing, he would have to do Bardeen and Brattain one better.

His device, the junction (sandwich) transistor, was developed in a burst of creativity and anger, mostly in a hotel room in Chicago. It took him a total of four weeks of working pen on paper, although it took another two years before he could actually build one. His device was more rugged and more practical than Bardeen and Brattain's point-contact transistor, and much easier to manufacture.  It became the central artifact of the electronic age. Author Michael Riordan says Bardeen and Brattain got "pushed aside." That insult broke the team apart, turning a once cooperative environment into one that was highly competitive. The problems of whose names should be on the patent for the device, and who should be featured in publicity photographs, sent tensions higher still.

Bell Labs decided to unveil the invention on June 30, 1948. With the help of engineer John Pierce, who wrote science fiction in his spare time, Bell Labs settled on the name "transistor"-- combining the ideas of "trans-resistance" with the names of other devices like thermistors. 

The invention got little attention at the time, either in the popular press or in industry. But Shockley saw its potential. He left Bell Labs to found Shockley Semiconductor in Palo Alto, California. He hired superb engineers and physicists, but, according to physical chemist Harry Sello, Shockley's personality drove out eight of his best and brightest. Those "traitorous eight" founded a new company called Fairchild Semiconductor. Bob Noyce and Gordon Moore, two of the eight, went on to form Intel Corporation. They (and others at Texas Instruments) co-invented the integrated circuit. Today, Intel produces billions of transistors daily on its integrated circuits, yet Bardeen, Brattain, and Shockley earned very little money from their research. Nonetheless, Shockley's company was the beginning of Silicon Valley.

Bardeen left Bell Labs for the University of Illinois, where he won a second Nobel Prize. Brattain stayed on for several years, and then left to teach. Shockley lost his company and taught at Stanford for a while, and then got involved in a notorious controversy over race, genetics and intelligence that destroyed his reputation.

In the 1950s and 1960s, most U.S. companies chose to focus their attentions on the military market in producing transistor products. That left the door wide open for Japanese engineers like Masaru Ibuka and Akio Morita, who founded a new company named Sony Electronics that mass-produced tiny transistorized radios. Bell Labs' President Emeritus Ian Ross said that part of their success lay in developing the ability to quickly mass-produce transistors.

The transistorized radio changed the world, opening up the information age. Information could quickly be scattered to the ends of the Earth, to the point that historian Charles Stewart heard about the assassination of Martin Luther King Jr. from Bedouin tribesmen in the Sahara shortly after it happened. 

The original three met several times after their breakup: once in Stockholm, Sweden, to receive the 1956 Nobel Prize for their contributions to physics, and once again at Bell Labs in 1972 to commemorate the 25^th anniversary of their inventions. They were celebrating something that they could not know when they first began working on the transistor -- that they were going to change the world.

by Philip Roumeliotis

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