The Innovators

by Walter Isaacson

  The key to innovation—at Bell Labs and in the digital age in general—was realizing that there was no conflict between nurturing individual geniuses and promoting collaborative teamwork. It was not either-or. Indeed, throughout the digital age, the two approaches went together. Creative geniuses (John Mauchly, William Shockley, Steve Jobs) generated innovative ideas. Practical engineers (Presper Eckert, Walter Brattain, Steve Wozniak) partnered closely with them to turn concepts into contraptions. And collaborative teams of technicians and entrepreneurs worked to turn the invention into a practical product. When part of this ecosystem was lacking, such as for John Atanasoff at Iowa State or Charles Babbage in the shed behind his London home, great concepts ended up being consigned to history’s basement. And when great teams lacked passionate visionaries, such as Penn after Mauchly and Eckert left, Princeton after von Neumann, or Bell Labs after Shockley, innovation slowly withered.

  * * *

  The need to combine theorists with engineers was particularly true in a field that was becoming increasingly important at Bell Labs: solid-state physics, which studied how electrons flow through solid materials. In the 1930s, Bell Labs engineers were tinkering with materials such as silicon—after oxygen the most common element in the earth’s crust and a key component of sand—in order to juice them into performing electronic tricks. At the same time in the same building, Bell theorists were wrestling with the mind-bending discoveries of quantum mechanics.

  Quantum mechanics is based on theories developed by the Danish physicist Niels Bohr and others about what goes on inside an atom. In 1913 Bohr had come up with a model of atomic structure in which electrons orbited around a nucleus at specific levels. They could make a quantum leap from one level to the next, but never be in between. The number of electrons in the outer orbital level helped to determine the chemical and electronic properties of the element, including how well it conducted electricity.

  Some elements, such as copper, are good conductors of electricity. Others, such as sulfur, are horrible conductors, and are thus good insulators. And then there are those in between, such as silicon and germanium, which are known as semiconductors. What makes them useful is that they are easy to manipulate into becoming better conductors. For example, if you contaminate silicon with a tiny amount of arsenic or boron, its electrons become more free to move.

  The advances in quantum theory came at the same time that metallurgists at Bell Labs were finding ways to create new materials using novel purification techniques, chemical tricks, and recipes for combining rare and ordinary minerals. In seeking to solve some everyday problems, like vacuum-tube filaments that burned out too quickly or telephone-speaker diaphragms that sounded too tinny, they were mixing new alloys and developing methods to heat or cool concoctions until they performed better. By trial and error, like cooks in a kitchen, they were creating a revolution in materials science that would go hand in hand with the theoretical revolution that was occurring in quantum mechanics.

  As they experimented with their samples of silicon and germanium, the chemical engineers at Bell Labs stumbled across evidence for much of what the theorists were conjecturing.I It became clear that there was a lot that the theorists, engineers, and metallurgists could learn from one another. So in 1936 a solid-state study group was formed at Bell Labs that included a potent mix of practical and theoretical stars. It met once a week in the late afternoon to share findings, engage in a bit of academic-style trash talk, and then adjourn for informal discussions that lasted late into the night. There was value to getting together in person rather than just reading each other’s papers: the intense interactions allowed ideas to be kicked into higher orbits and, like electrons, occasionally break loose to spark chain reactions.

  Of all the people in the group, one stood out. William Shockley, a theorist who had arrived at Bell Labs right when the study group was being formed, impressed the others, and sometimes frightened them, with both his intellect and his intensity.

  WILLIAM SHOCKLEY

  William Shockley grew up with a love of both art and science. His father studied mine engineering at MIT, took music courses in New York, and learned seven languages as he wandered through Europe and Asia as an adventurer and mineral speculator. His mother majored in both math and art at Stanford and was one of the first known climbers to succeed in a solo ascent of Mt. Whitney. They met in a tiny Nevada mining village, Tonopah, where he was staking claims and she had gone to do surveying work. After they were married, they moved to London, where their son was born in 1910.

  William would be their only child, and for that they were thankful. Even as a baby he had a ferocious temper, with fits of rage so loud and long that his parents kept losing babysitters and apartments. In a journal his father described the boy “screaming at the top of his voice and bending and throwing himself back” and recorded that he “has bitten his mother severely many times.”5 His tenacity was ferocious. In any situation, he simply had to have his way. His parents eventually adopted a policy of surrender. They abandoned any attempt to discipline him, and until he was eight they home-schooled him. By then they had moved to Palo Alto, where his mother’s parents lived.

  Convinced that their son was a genius, William’s parents had him evaluated by Lewis Terman,II who had devised the Stanford–Binet IQ test and was planning a study of gifted children. Young Shockley scored in the high 120s, which was respectable but not enough for Terman to label him a genius. Shockley would become obsessed by IQ tests and use them to assess job applicants and even colleagues, and he developed increasingly virulent theories about race and inherited intelligence that would poison the later years of his life.6 Perhaps he should have learned from his own life the shortcomings of IQ tests. Despite being certified as a nongenius, he was smart enough to skip middle school and get a degree from Caltech and then a doctorate in solid-state physics from MIT. He was incisive, creative, and ambitious. Even though he loved performing magic tricks and playing practical jokes, he never learned to be easygoing or friendly. He had an intellectual and personal intensity, resonating from his childhood, that made him difficult to deal with, all the more so as he became successful.

  When Shockley graduated from MIT in 1936, Mervin Kelly came up from Bell Labs to interview him and offered him a job on the spot. He also gave Shockley a mission: find a way to replace vacuum tubes with a device that was more stable, solid, and cheap. After three years, Shockley became convinced he could find a solution using solid material such as silicon rather than glowing filaments in a bulb. “It has today occurred to me that an amplifier using semiconductors rather than vacuum is in principle possible,” he wrote in his lab notebook on December 29, 1939.7

  Shockley had the ability to visualize quantum theory, how it explained the movement of electrons, the way a choreographer can visualize a dance. His colleagues said that he could look at semiconducting material and see the electrons. However, in order to transform his artist’s intuitions into a real invention, Shockley needed a partner who was an adroit experimenter, just as Mauchly needed Eckert. This being Bell Labs, there were many in the building, most notably the merrily cantankerous westerner Walter Brattain, who enjoyed making ingenious devices with semiconducting compounds such as copper oxide. For example, he built electric rectifiers, which turn alternating current into direct current, based on the fact that current flows in only one direction through an interface where a piece of copper meets a layer of copper oxide.

  Brattain grew up on an isolated ranch in eastern Washington State, where as a boy he herded cattle. With his raspy voice and homespun demeanor, he affected the self-deprecating style of a confident cowboy. He was a natural-born tinkerer with deft fingers, and he loved devising experiments. “He could put things together out of sealing wax and paper clips,” recalled an engineer he worked with at Bell Labs.8 But he also had a laid-back cleverness that led him to seek shortcuts rather than plod through repetitious trials.

  Shockley had an idea for finding a solid-state re
placement for a vacuum tube by putting a grid into a layer of copper oxide. Brattain was skeptical. He laughed and told Shockley that he had tried that approach before, and it never ended up producing an amplifier. But Shockley kept pushing. “It’s so damned important,” Brattain finally said, “that if you’ll tell me how you want it made, we’ll try it.”9 But as Brattain predicted, it didn’t work.

  Before Shockley and Brattain could figure out why it had failed, World War II intervened. Shockley went off to become a research director in the Navy’s antisubmarine group, where he developed analyses of bomb detonation depths to improve attacks on German U-boats. He later traveled to Europe and Asia to help B-29 bomber fleets use radar. Brattain likewise left for Washington to work on submarine-detection technologies for the Navy, focusing on airborne magnetic devices.

  THE SOLID-STATE TEAM

  While Shockley and Brattain were away, the war was transforming Bell Labs. It became part of the triangular relationship that was forged among the government, research universities, and private industry. As the historian Jon Gertner noted, “In the first few years after Pearl Harbor, Bell Labs took on nearly a thousand different projects for the military—everything from tank radio sets to communications systems for pilots wearing oxygen masks to enciphering machines for scrambling secret messages.”10 The staff doubled in size, to nine thousand.

  Having outgrown its Manhattan headquarters, most of Bell Labs moved to two hundred rolling acres in Murray Hill, New Jersey. Mervin Kelly and his colleagues wanted their new home to feel like an academic campus, but without the segregation of various disciplines into different buildings. They knew that creativity came through chance encounters. “All buildings have been connected so as to avoid fixed geographical delineation between departments and to encourage free interchange and close contact among them,” an executive wrote.11 The corridors were extremely long, more than the length of two football fields, and designed to promote random meetings among people with different talents and specialties, a strategy that Steve Jobs replicated in designing Apple’s new headquarters seventy years later. Anyone walking around Bell Labs might be bombarded with random ideas, soaking them up like a solar cell. Claude Shannon, the eccentric information theorist, would sometimes ride a unicycle up and down the long red terrazzo corridors while juggling three balls and nodding at colleagues.III It was a wacky metaphor for the balls-in-the-air ferment in the halls.

  In November 1941 Brattain had made his last journal entry, into his notebook #18194, before leaving Bell Labs in Manhattan for his wartime service. Almost four years later, he picked up that same notebook in his new lab in Murray Hill and began anew with the entry “The war is over.” Kelly assigned him and Shockley to a research group that was designed “to achieve a unified approach to the theoretical and experimental work of the solid state area.” Its mission was the same as they had before the war: to create a replacement for the vacuum tube using semiconductors.12

  When Kelly sent around the list of who was going to be on the solid-state research group, Brattain marveled that it included no losers. “By golly! There isn’t an s.o.b. in the group,” he recalled saying, before pausing to worry, “Maybe I was the s.o.b. in the group.” As he later declared, “It was probably one of the greatest research teams ever pulled together.”13

  Shockley was the primary theoretician, but given his duties as the team’s supervisor—he was on a different floor—they decided to bring in an additional theorist. They chose a soft-spoken expert in quantum theory, John Bardeen. A child genius who had skipped three grades in school, Bardeen had written his doctoral thesis under Eugene Wigner at Princeton and during his wartime service in the Naval Ordnance Laboratory discussed torpedo design with Einstein. He was one of the world’s greatest experts on using quantum theory to understand how materials conduct electricity, and he had, according to colleagues, a “genuine ability to collaborate easily with experimentalist and theorist alike.”14 There was initially no separate office for Bardeen, so he ensconced himself in Brattain’s lab space. It was a smart move that showed, once again, the creative energy generated by physical proximity. By sitting together, the theorist and the experimentalist could brainstorm ideas face-to-face, hour after hour.

  Unlike Brattain, who was voluble and talkative, Bardeen was so quiet that he was dubbed “Whispering John.” To understand his mumbling, people had to lean forward, but they learned that it was worth it. He was also contemplative and cautious, unlike Shockley, who was lightning-quick and impulsively spouted theories and assertions.

  Their insights came from interactions with each other. “The close collaboration between experimentalists and theorists extended through all stages of the research, from the conception of the experiment to the analysis of the results,” said Bardeen.15 Their impromptu meetings, usually led by Shockley, occurred almost every day, a quintessential display of finish-each-other’s-sentence creativity. “We would meet to discuss important steps almost on the spur of the moment,” Brattain said. “Many of us had ideas in these discussion groups, one person’s remarks suggesting an idea to another.”16

  These meetings became known as “blackboard sessions” or “chalk talks” because Shockley would stand, chalk in hand, scribbling down ideas. Brattain, ever brash, would pace around the back of the room and shout out objections to some of Shockley’s suggestions, sometimes betting a dollar they wouldn’t work. Shockley didn’t like losing. “I finally found out he was annoyed when he paid me off once in ten dimes,” Brattain recalled.17 The interactions would spill over into their social outings; they often played golf together, went out for beer at a diner called Snuffy’s, and joined in bridge matches with their spouses.

  THE TRANSISTOR

  With his new team at Bell Labs, Shockley resurrected the theory he had been playing with five years earlier for a solid-state replacement for the vacuum tube. If a strong electrical field was placed right next to a slab of semiconducting material, he posited, the field would pull some electrons to the surface and permit a surge of current through the slab. This potentially would allow a semiconductor to use a very small signal to control a much larger signal. A very low-powered current could provide the input, and it could control (or switch on and off) a much higher-powered output current. Thus the semiconductor could be used as an amplifier or an on-off switch, just like a vacuum tube.

  There was one small problem with this “field effect”: when Shockley tested the theory—his team charged a plate with a thousand volts and put it only a millimeter away from a semiconductor surface—it didn’t work. “No observable change in current,” he wrote in his lab notebook. It was, he later said, “quite mysterious.”

  Figuring out why a theory failed can point the way to a better one, so Shockley asked Bardeen to come up with an explanation. The two of them spent hours discussing what are known as “surface states,” the electronic properties and quantum-mechanical description of the atom layers closest to the surface of materials. After five months, Bardeen had his insight. He went to the blackboard in the workspace he shared with Brattain and began to write.

  Bardeen realized that when a semiconductor is charged, electrons become trapped on its surface. They cannot move about freely. They form a shield, and an electric field, even a strong one a millimeter away, cannot penetrate this barrier. “These added electrons were trapped, immobile, in surface states,” Shockley noted. “In effect, the surface states shielded the interior of the semiconductor from the influence of the positively charged control plate.”18

  The team now had a new mission: find a way to break through the shield that formed on the surface of semiconductors. “We concentrated on new experiments related to Bardeen’s surface states,” Shockley explained. They would have to breach this barrier in order to goose the semiconductor into being able to regulate, switch, and amplify current.19

  Progress was slow over the next year, but in November 1947 a series of breakthroughs led to what became known as the Miracle Month. Bardeen buil
t on the theory of the “photovoltaic effect,” which says that shining light on two dissimilar materials that are in contact with one another will produce an electric voltage. That process, he surmised, might dislodge some of the electrons that created the shield. Brattain, working side by side with Bardeen, devised ingenious experiments to test out ways to do this.

  After a while, serendipity proved to be their friend. Brattain conducted some of the experiments in a thermos so he could vary the temperature. But condensation on the silicon kept gunking up the measurements. The best way to solve that would be to put the entire apparatus in a vacuum, but that would have required a lot of work. “I’m essentially a lazy physicist,” Brattain admitted. “So I got the idea to immerse the system in a dielectric liquid.”20 He filled the thermos with water, which proved a simple way to avoid the condensation problem. He and Bardeen tried it out on November 17, and it worked beautifully.

  That was a Monday. Throughout that week, they bounced through a series of theoretical and experimental ideas. By Friday, Bardeen had come up with a way to eliminate the need to immerse the apparatus in water. Instead, he suggested, they could just use a drop of water, or a little gel, right where a sharp metal point jabbed down into the piece of silicon. “Come on, John,” Brattain responded enthusiastically. “Let’s go make it.” One challenge was that the metal point couldn’t be allowed contact with the water drop, but Brattain was an improvisational wizard and solved that with a bit of sealing wax. He found a nice slab of silicon, put a tiny drop of water on it, coated a piece of wire with wax to insulate it, and jabbed the wire through the water drop and into the silicon. It worked. It was able to amplify a current, at least slightly. From this “point-contact” contraption the transistor was born.