Germanium, a plastic wedge and gold foil, demonstrated on 23 December 1947 (1947)
Bardeen and Brattain's point-contact amplifier at Bell Labs; Shockley's junction design followed within weeks
General knowledge · Inventions & discoveries
The transistor
1947
Invention — electronics
On 23 December 1947 John Bardeen and Walter Brattain demonstrated to their managers at Bell Telephone Laboratories a sliver of germanium with two gold contacts pressed onto it that amplified a signal: the point-contact device. William Shockley, who had directed the group and was piqued at being left off the patent, worked out the more robust junction design within weeks. The three shared the 1956 Nobel Prize in Physics, and their small, cool, durable replacement for the vacuum tube became the building block of every computer since.
How to spot them
- ▸Murray Hill, New Jersey, December 1947; germanium, gold foil and a plastic wedge
- ▸Three terminals with strange names: emitter, base and collector
- ▸Its name was chosen by ballot, coined to rhyme with varistor and thermistor
- ▸One of its inventors is the only person to win two Nobel Prizes in Physics
Key facts
A name coined from 'transresistance', to rhyme with varistor and thermistor
Suggested by John R. Pierce and chosen by an internal ballot, beating 'Iotatron' and 'Crystal Triode'
Emitter, base and collector
The three terminals of the bipolar version; the field-effect kind has source, gate and drain
The Regency TR-1 of 1954, the first commercial radio built with them (1954)
It sold for $49.95; Sony's TR-55 followed in Japan in 1955 and began the company's rise
The 'traitorous eight' who walked out on Shockley in 1957 (1957)
They founded Fairchild Semiconductor; two of them, Noyce and Moore, later founded Intel
Moore's law describes how many of them fit on a chip (1965)
Gordon Moore's observation that the number on an integrated circuit doubles roughly every two years
Julius Lilienfeld patented the idea in the 1920s but never made one work (1925–26)
His field-effect patents were later cited against Bell Labs' own claims
Key ideas
- It is a valve for electricity: a small current or voltage at one terminal controls a much larger current between the other two, giving amplification and switching from the same device
- The trick is doping — adding impurities to make n-type silicon with spare electrons or p-type with spare holes — and stacking them so a junction controls the flow
- Digital logic needs only switching, not amplification, which is why hundreds of millions of these can sit on a chip doing nothing but turning on and off
Quick-fire facts
- •John Bardeen, Walter Brattain and William Shockley shared the 1956 Nobel Prize in Physics
- •Bardeen is the only person to have won the Nobel Prize in Physics twice: 1956 for this, and 1972 for the BCS theory of superconductivity
- •The first devices were germanium; silicon took over because its oxide makes an excellent insulating layer, the basis of the planar process
- •Shockley moved to Mountain View in 1956, seeding what became Silicon Valley, but his management drove out the eight who founded Fairchild
- •The MOSFET, the type in almost every chip today, was demonstrated by Mohamed Atalla and Dawon Kahng at Bell Labs in 1959
- •Shockley's later advocacy of eugenics destroyed his scientific reputation
- •Jack Kilby and Robert Noyce independently invented the integrated circuit in 1958–59; Kilby received a Nobel Prize in 2000
- •It is by a wide margin the most manufactured artefact in history, with an estimated 10^22 or more made
- •The Bell Labs announcement was made at a press conference on 30 June 1948 and attracted little attention
Drill it — 10 cards
1 / 10new card
Sources
- The Nobel Foundation — The Nobel Prize in Physics 1956
- Michael Riordan and Lillian Hoddeson — Crystal Fire: The Invention of the Transistor and the Birth of the Information Age