Walter Brattain
Walter Brattain (1902-1987) was an American experimental physicist at Bell Labs and the third name on the 1956 Nobel Prize in Physics for the transistor, shared with John Bardeen and William Shockley. Where Bardeen supplied the theory of semiconductor surfaces, Brattain was the person at the bench who prepared the crystals, built the contacts and observed the effect in December 1947. His career runs from a childhood in the American Northwest, through nearly four decades at Bell Labs, to a second career teaching undergraduates at the college where he had studied.
His early life and training were rooted in the Pacific Northwest. Brattain was born in Amoy, China, where his father taught, and grew up in the state of Washington, where his family ran a cattle ranch. He studied physics and mathematics at Whitman College in Walla Walla, earned a master's degree at the University of Oregon and a doctorate at the University of Minnesota in 1929. Joining Bell Labs that same year, he began in vacuum-tube physics, studying thermionic emission and related problems, and then moved to the study of semiconductors and metal-semiconductor rectifiers, which later gave him the surface-science background the transistor project needed.
His specialty was getting surfaces and contacts to behave. At Bell Labs in the 1930s he worked on the copper-oxide rectifier and on how electrons cross a metal-to-semiconductor boundary. During the Second World War he contributed to magnetometer work for detecting submarines. After the war he joined Shockley's semiconductor group and worked most closely with Bardeen, building experiments around germanium and silicon surfaces, with help from the physical chemist Robert Gibney and others. His patience in controlling cleanliness, moisture and contact geometry mattered because surface states were exactly the kind of effect that disappears when a sample is handled carelessly.
The key experiments of 1947 turned a theory into a device. After Bardeen's surface-state picture explained the failure of simple field-effect devices, the pair tried arrangements that could show amplification despite the surface states. One used an electrolyte on silicon; the one that mattered used two closely spaced metal contacts on germanium. On 15-16 December 1947 the arrangement amplified a signal, and on 23 December 1947 it was demonstrated to Bell Labs management. Brattain's skill with the fine mechanical details of these contacts is the reason that the first transistor worked on a lab bench and not just on a blackboard.
Brattain remained an experimentalist rather than an executive, and he went back to teaching. He was less involved than Shockley in the commercial development of semiconductors and stayed in research at Bell Labs until retiring in 1967, then taught at Whitman College and remained associated with it, advising and teaching physics students for years. He continued working on surface physics and biological membranes, and he lived to see the transistor become the basis of an industry. He died in Seattle in 1987.
A misconception to avoid is that the invention was only theory made real, or only a happy accident at the bench. The device came from a tight loop between a theorist's model of surfaces and an experimenter's ability to change them, and Brattain's name sits on the Nobel Prize because of this. Modern semiconductor manufacturing still depends on the same principle: processes that grow and clean silicon surfaces and the oxide layers on them are measured and controlled to atomic scale, and the interface defects Bardeen predicted and Brattain studied are still a core concern in chip fabrication and in the reliability of devices.
Read Walter Brattain as the hands-on counterpart to theory: the experimentalist who learned to make a semiconductor surface do what the equations suggested, and who afterward went back to the classroom of his youth.