1947: The Transistor
Until the mid-1940s, vacuum tubes were the state-of-the-art in electronics.
Capable of converting alternating current to direct current (AC to DC) and amplifying an electronic signal, vacuum tubes were used in everything from switching telephone calls to building the first high-speed computer, ENIAC.
But the limitations were clear. Vacuum tubes were bulky, and to make more powerful computers, more tubes were needed. (17,000 tubes were used in ENIAC!) Tubes were also fragile and overheated easily.
In 1945, Bell Labs established a research group to look into finding a solution. The group was led by William Shockley and included Walter Brattain and John Bardeen. After two years, Bardeen and Brattain created an amplifying circuit that seemed to work, using the element germanium. They called it the point-contact transistor.
The discovery did not gain attention until 1951, when Shockley improved upon the original idea with a junction transistor. The transistor was a solid (giving rise to the term “solid-state technology”), but had the electrical properties of a vacuum tube. Furthermore, it was inexpensive, sturdy, used little power, worked instantly, and, best of all, was tiny.
The three men shared the 1956 Nobel Prize in physics for “their researches on semiconductors and their discovery of the transistor effect.”
The invention of the transistor and the integrated circuit marked the beginning of microelectronics, a field that relies on tools for miniaturization. The semiconductor industry is one of the largest technology drivers in the field of nanotechnology. Researchers today are looking to enable the creation of chips holding billions or even trillions of nanoscale transistors.
(US Patent 2,569,347, Sept. 25, 1951, applied for June 26, 1948).