William Bradford Shockley
William Bradford Shockley (February 13, 1910 - August 12, 1989) was an American physicist. Along with John Bardeen and Walter Houser Brattain, he was awarded the 1956 Nobel Prize in Physics "for their research on semiconductors and the invention of the transistor."
In 1955, Shockley left Bell Laboratories and returned to his hometown of Palo Alto, California, near Stanford University, to create his own company, Shockley Semiconductors Laboratory, with financial support from Arnold Beckman, from Beckman Instruments. Leveraging his prestige and financial backing from Beckman Instruments, he tried to convince several of his Bell coworkers to join him in the new company; none wanted. He therefore began to search the universities for the most outstanding students to form the company with them. But given their entrepreneurial style, eight of the researchers left the company in 1957 to form Fairchild Semiconductor. Among them were Robert Noyce and Gordon Moore who would later create Intel.
In the late 1960s, Shockley made controversial statements about intellectual differences between the races, arguing that intelligence tests showed a genetic factor in intellectual ability revealing that African-Americans were inferior to Caucasian Americans. and that the higher rate of reproduction among the former exerted a regressive effect on evolution.
Among his publications, "Electrons and holes in the semiconductor" stands out, a work published in 1950.
Career
Shockley was one of the first recruits to Bell Laboratories by Mervin Kelly, who became the company's director of research in 1936 and focused on recruiting solid-state physicists. Shockley joined a group led by Clinton Davisson in Murray Hill, New Jersey. Executives at Bell Laboratories had theorized that semiconductors could offer solid-state alternatives to the vacuum tubes used throughout the Bell National Telephone System. Shockley conceived a series of designs based on copper oxide semiconductor materials, and with Walter Brattain he unsuccessfully attempted to create a prototype in 1939.
Shockley published several seminal articles on solid state physics in the Physical Review. In 1938, he received his first patent, 'Electron Discharge Device', on an electron multiplier.
When World War II broke out, Shockley's previous research was interrupted and he devoted himself to radar research in Manhattan, New York. In May 1942, he took a leave of absence from Bell Laboratories to become research director in Columbia University's Anti-Submarine Warfare Operations Group. This involved devising methods to counter submarine tactics with improved convoy techniques, optimizing depth charge patterns, etc. Shockley frequently traveled to the Pentagon and Washington to meet with high-ranking officials and government officials.
In 1944, he organized a training program for B-29 bomber pilots to use the new radar bombsights. At the end of 1944 he made a three-month tour of the bases around the world to evaluate the results. For this project, Secretary of War Robert Patterson awarded Shockley the Medal of Merit on October 17, 1946.
In July 1945, Shockley was asked by the War Department to prepare a report on the question of probable casualties from an invasion of the Japanese mainland. Shockley concluded:
- If the study shows that the behavior of nations in all historical cases comparable to that of Japan has in fact been invariably consistent with the behavior of the troops in the battle, then it means that the Japanese dead and unused at the time of defeat will exceed the corresponding number of the Germans. In other words, we'll probably have to kill at least between 5 and 10 million Japanese. This could cost us between 1.7 and 4 million casualties, including between 400,000 and 800,000 dead.
This report influenced the US decision to drop atomic bombs on Hiroshima and Nagasaki, which preceded Japan's surrender.
Shockley was the first physicist to propose a log-normal distribution to model the process of creating scientific research articles.
Development of the transistor
Shortly after the war ended in 1945, Bell Laboratories formed a solid-state physics group, led by Shockley and chemist Stanley Morgan, which included John Bardeen, Walter Brattain, physicist Gerald Pearson, chemist Robert Gibney, electronics expert Hilbert Moore, and various technicians. His remit was to find a solid-state alternative to fragile glass vacuum tube amplifiers. His first attempts were based on Shockley's ideas about using an external electric field on a semiconductor to affect its conductivity. These experiments always failed in all kinds of configurations and materials. The group was deadlocked until Bardeen suggested a theory that invoked surface states that prevented the field from penetrating the semiconductor. The group shifted their focus to studying these surface states and met almost daily to discuss the work. The rapport of the group was excellent and ideas were freely exchanged.
By the winter of 1946 they had enough results for Bardeen to submit a paper on surface states to the Physical Review. Brattain began conducting experiments to study surface states through observations made by shining an intense light onto the semiconductor surface. This led to several more papers (one of them co-authored with Shockley), which estimated that the density of surface states was more than enough to explain his failed experiments. The pace of work accelerated considerably when they began to surround the point contacts between the semiconductor and the conductive wires with electrolytes. Moore built a circuit that allowed them to easily vary the frequency of the input signal. Finally, they began to get some evidence of power amplification when Pearson, acting on Shockley's suggestion, put a voltage on a drop of glycol borate placed across a PN junction.
Lawyers at Bell Laboratories soon discovered that Shockley's field-effect principle had been anticipated and that devices based on it had been patented in the 1930s by Julius Lilienfeld, who filed his MESFET-like patent in Canada on 22 October 1925. Although the patent appeared "breakable" (it couldn't work) the patent attorneys based one of their four patent applications on the Bardeen-Brattain point contact design alone. Three others (submitted first) covered electrolyte-based transistors with Bardeen, Gibney, and Brattain as inventors.
Shockley's name did not appear on any of these patent applications. This angered Shockley, who thought his name should also be on the patents because the work was based on his field-effect idea. He even strove to have the patent written in his name alone, and communicated his intentions to Bardeen and Brattain.
Shockley, angry at not being included in the patent applications, secretly continued his own work to build a different type of transistor based on junctions rather than point contacts; he hoped that this type of design would have a better chance of being commercially viable. He believed that the point contact transistor would be fragile and difficult to manufacture. Shockley was also dissatisfied with certain parts of the point-contact transistor explanation of operation and entertained the possibility of minority carrier injection.
On February 13, 1948, another member of the team, John N. Shive, built a point-contact transistor with bronze contacts on the front and back of a thin wedge of germanium, showing that holes could diffuse at through the bulk germanium and not just along the surface as previously thought. Shive's invention prompted Shockley's invention of the junction transistor. A few months later he invented an entirely new type of transistor, considerably more robust, with a layered or "sandwich" structure. This structure was used for the vast majority of transistors in the 1960s, and became the bipolar junction transistor. Shockley later described the team's operation as a "mixture of cooperation and competition." He also said that he kept some of his own work a secret until "his hand was forced." by Shive's breakthrough in 1948. Shockley produced a fairly comprehensive description of what he called the "sandwich" transistor, and a first proof of principle was obtained on April 7, 1949.
Meanwhile, Shockley was working on his magnum opus, Electrons and Holes in Semiconductors, which was published as a 558-page treatise in 1950. The tome included Shockley's critical insights on drift and diffusion and differential equations governing the flow of electrons in solid-state crystals. [The Shockley diode equation is also described. This seminal work became the reference text for other scientists working to develop and improve new variants of the transistor and other semiconductor-based devices.
This led to his invention of the 'junction transistor', which was announced at a press conference on July 4, 1951.
In 1951, he was elected to the National Academy of Sciences (NAS). He was forty-one years old; this was quite young for such a choice. Two years later, he was chosen to receive the prestigious NAS Comstock Prize in Physics, and received many other awards and honors.
The ensuing publicity generated by the "invention of the transistor" he often propelled Shockley to the fore, much to the chagrin of Bardeen and Brattain. However, the management of Bell Laboratories always presented the three inventors as a team. Although Shockley corrected the record when journalists gave him sole credit for the invention, he ended up angering and alienating Bardeen and Brattain, essentially preventing both of them from working on the junction transistor. Bardeen began searching for a theory for superconductivity and left Bell Laboratories in 1951. Brattain refused to continue working with Shockley and was assigned to another group. Neither Bardeen nor Brattain had much to do with the development of the transistor beyond the first year after its invention.
Shockley left Bell Laboratories around 1953 and took a job at Caltech.
Shockley, Bardeen and Brattain received the Nobel Prize in Physics in 1956.
Shockley Semiconductor
In 1956, Shockley established the Shockley Semiconductor Laboratory in Mountain View, California, which was near his elderly mother in Palo Alto, California. The company, a division of Beckman Instruments, Inc, was the first establishment to he worked on silicon semiconductor devices in what came to be known as Silicon Valley.
Shockley recruited brilliant employees to his company, but alienated them by relentlessly undermining them. "He may have been the worst manager in the history of electronics," according to his biographer Joel Shurkin. Shockley was autocratic, domineering, erratic, hard to please, and increasingly paranoid.<ref=":8" /> In a well-known incident, he demanded lie detector tests to find the "culprit"; after a company secretary suffered a minor cut.<ref=":8">Crystal Fire p. 247</ref> In late 1957, eight of Shockley's top researchers, who would come to be known as the "Traitor Eight", resigned after Shockley decided not to continue research on silicon-based semiconductors. They went on to form Fairchild Semiconductor, a loss from which Shockley Semiconductor never recovered and which led to its purchase by another company three years later. Over the course of the next 20 years, more than 65 new companies would end up having employee connections to Fairchild.
A group of about thirty colleagues have met on and off since 1956 to remember the time when Shockley was, the group's organizer said in 2002, "the man who brought silicon to Silicon Valley" 34;.