How it began
In early 1945 William Shockley began organizing a solid-state physics group at Bell Labs in Murray Hill, New Jersey. His own field-effect amplifier failed to work as intended. Theorist John Bardeen suggested that electrons on the semiconductor surface were blocking electric fields, and he and experimentalist Walter Brattain studied these surface states. On December 16, 1947, they achieved the first semiconductor amplifier, and on December 23 they demonstrated it to lab officials. Bell Labs announced it publicly in New York on June 30, 1948.
Before it existed
The Bell Telephone System relied on vacuum tubes and electromechanical switches, which the Computer History Museum describes as unreliable. Shockley's group was set up in part to find semiconductor replacements for them. The work built on wartime efforts to produce very pure germanium crystal diodes for radar receivers.
How it works
Brattain wrapped a ribbon of gold foil around a small plastic wedge and sliced it at the tip with a razor, making two closely spaced contacts. Pressed onto a slab of high-purity germanium, the contacts formed an amplifier: the voltage on one contact modulated the current flowing through the other, amplifying the input signal up to 100 times. The name, credited to John Pierce, combined "transconductance" or "transfer" with "varistor."
How it spread
Shockley developed a junction transistor made of three layers of semiconductor, which was more reliable than the point-contact design and became the industry standard. Western Electric began licensing transistor production rights in 1951, and Bell Labs held symposia for licensees. The proceedings of the 1952 meeting were nicknamed "Mother Bell's Cookbook." Shockley left in 1955 to found one of the first semiconductor firms in what became Silicon Valley.
Who pushed back
The Linda Hall Library notes that Bell Labs staff were convinced the transistor was a major innovation, but the popular press did not share that view after the 1948 press conference. Inside the lab, Shockley resented that the device was credited to Bardeen and Brattain. At about the same time, Herbert Matare and Heinrich Welker in France independently built a similar amplifier, the "transistron," and applied for a patent in August 1948.
What lasted
Bardeen, Brattain and Shockley received the 1956 Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect." The Linda Hall Library describes transistors as the invisible foundation of the digital world, each tracing its origin to the December 1947 experiment in New Jersey.
