PERKIN MEDAL
Hannay Wins 1983 Perkin Medal for Solid-State Research (NAE). His numerous honors include the 1982 Industrial Research Institute In a year when Time magazine has Medal. named the computer as "Man of the Hannay's scientific career began Year," it seems appropriate that with a B.A. in chemistry in 1942 from chemical research that contributed Swarthmore College and a Ph.D. in vitally to development of the modern physical chemistry two years later computer and to the communications from Princeton University. He then and electronics revolutions is being joined the Manhattan Project, workhonored by award of the Perkin ing on gaseous diffusion—first at Medal for 1983. Princeton and subsequently at Bell At a Society of Chemical Industry Labs. (SCI) dinner in New York City last After the war, Hannay's first "ciweek, the gold medal was presented vilian" project at Bell was to try to to N. Bruce Hannay, who retired a unravel the mechanism of thermyear ago as vice president for re- ionic emission from the oxide cathsearch at Bell Laboratories. One of odes of electron tubes—ironic, conthe most prestigious awards for sidering his later contributions to the "outstanding contributions to ap- electronics revolution. "That seems plied chemistry," the medal is given like an archaic subject now," he annually to a scientist selected jointly commented in a recent interview by six U.S. chemical associations: SCI; with C&EN. But at the time, all elecAmerican Chemical Society; Ameri- tronic circuits depended upon the can Institute of Chemists; Societe de electron tube, and no one understood Chimie Industrielle, American Sec- how oxide cathodes worked. tion; American Institute of Chemical However, at the end of 1947, Engineers; and Electrochemical Society. Hannay, 62, was honored for his pioneering research in physical chemistry, particularly his contributions in mass spectrography and in the purification of silicon and growth of single silicon crystals. This work helped lay the foundation for the spectacular advances that have been made in semiconductors and other electronic and optical materials that make possible the transistors, integrated circuits, lasers, and other solid-state devices that are the heart of the electronics revolution. During a 38-year career spent entirely at Bell Labs—first as research scientist and then as research administrator—Hannay contributed significantly in the areas of science, technology, and public policy. Currently, he is foreign secretary of the National Academy of Engineering Richard J. Seltzer, C&EN Washington
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March 14, 1983 C&EN
physicists at Bell invented the first transistor. "Our view as to the importance of understanding the fundamentals of electron emission changed overnight because the future was going to be with transistors," Hannay says. A vital consideration for the semiconductor materials used in transistors was the elevated standard of purity—"much purer than anything that had been known before." However, "no chemical analytical methods went down to the low concentrations that were significant in semiconductor materials." Hannay's initial involvement in this area, therefore, was work to develop a mass spectrograph for the analysis of solids. This analytical method proved successful, and within a few years commercial instruments patterned after his prototype were introduced to analyze solids for trace impurities. In the early 1950s, Hannay was asked "to get into the heart of the silicon program." Silicon was much harder to purify and to work with than germanium—then used in all transistors. There had been "only rudimentary success" at growing single silicon crystals. "They were poor crystals. They were not pure. One could not make a transistor from them." Indeed, "there were all kinds of puzzling electrical effects. For example, when you heated a silicon crystal, its resistivity changed." He was given charge both of trying to launch silicon as a material—that is, to make single crystals large enough and pure enough to be useful—and of coordinating all activities on silicon, including the physics research and development work on silicon transistors. "We were successful. Not overnight—it was hard work. But first we reached the point where we could
grow respectable crystals of silicon. They didn't look like much by today's standards, but by the standards of the time they were quite good. Then we had to deal with the resistivity changes. We discovered previously undetected dissolved oxygen in the crystals. This electrically active oxygen resulted from a reaction between molten silicon and the fused quartz (silica) crucible used as a container for the crystal growth," Hannay explains. The group therefore developed a "floating zone" method of growing crystals. This new method used no crucible, but instead suspended the silicon in a vacuum, the melt being held together by surface tension. Crystals grown by this method were oxygen free. Substrates for integrated circuits are still grown by this method. Based on this work, Bell finally succeeded in making a silicon transistor and announced its achievement at a conference in 1953, back to back with a paper by Texas Instruments announcing independent development of its first silicon transistor. TI went on to commercialize the silicon transistor in transistor radios and other consumer products, while Bell pursued internal use of the transistor in telephone systems. Hannay considers himself "particularly fortunate" to have been at Bell when he was. "It was a very exciting period in science and technology, coinciding precisely with the great revolution in electronics that began with invention of the transistor," and with dramatic advances in solid-state physics and chemistry. "I was at the place where it started, at the center of the action." Through the 1950s, Hannay and his colleagues continued their studies in solid-state chemistry, investigating basic properties of semiconductors and looking at possible new semiconductors. For example, the group initiated work on the previously unexplored semiconductor gallium arsenide. Later, after invention of the laser, gallium arsenide became the preferred material for semiconductor lasers, which are the basis for optical communications systems and many other applications today. The group's research also
branched out into laser materials and superconductors. "The general interest that some of my associates and I had was how to manipulate the chemistry of a solid. That's the key to success in this field, because control over the structure and chemical composition of a solid is what gives rise to its unusual properties—electrical, optical, or magnetic." Indeed, he stresses, "In the whole materials business, we are learning how to tailor-make a material to produce desired properties. It's not just an empirical thing," as previously in the history of materials. "It's becoming a business where the science tells you beforehand what to do. This developed because of electronic materials, where we had to do it." Hannay moved from the research lab to full-time research administration in 1961, serving first as chemical director, and then, after 1967, as executive director for research in materials science and engineering. In 1973 he became vice president for research and patents. Research administrators at Bell remain very close to science, he notes, seeking to keep research programs alert to new scientific opportunities. For example, in both of his most recent positions at Bell, he put great emphasis on research on optical fibers for communications. "We had to learn how to purify the glass fiber material and to dope it in a controlled way with impurities to make communications-quality fibers that could
be used in optical systems." Now, optical systems are rapidly enlarging their role in communications. Last year, at age 61, Hannay took early retirement. The reorganization of the Bell Telephone System—with new functions and opportunities in data communications, computers, and other areas—meant a new era for Bell Labs. He decided to let someone else construct an appropriate research organization and programs for the new era. Moreover, after so many years there, "I also thought it would be nice to do some other things, although Bell Labs is a great place." He spends much time traveling as a consultant or acting as board member at several firms. He also serves on advisory committees to several government agencies and universities. And since 1976 Hannay has been NAE foreign secretary. A major focus of his NAE and National Academy of Sciences activities is the issue of how to increase the U.S.'s ability to innovate new technology and to compete in international markets on the basis of advances in or superior use of technology. Hannay and his wife have moved from New Jersey to the state of Washington, where he grew up, buying a house at Friday Harbor in the beautiful San Juan Islands. However, he notes wryly, his "retirement" has not yet permitted him time to try the unparalleled fishing in the salmon-rich waters a few feet from his door. • March 14, 1983 C&EN
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