The Idea Factory: Bell Labs and the Great Age of American Innovation (25 page)

His early work at Bell Labs had been on plastics and rubber. After Mervin Kelly reorganized the Labs research department after the war, however, Fuller begun working on semiconductors such as germanium and silicon, with a special interest in how infinitesimal impurities affected them. He had noticed that a germanium crystal could be rendered impure if someone touched it after handling a brass doorknob,
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and he wondered if there was a way to take advantage of the remarkable sensitivity of these crystals to impurities. By the time Morry Tanenbaum got to know him, Fuller was using a technique called diffusion that suggested a way to manipulate the concentrations of impurities in silicon with remarkable precision.

In diffusion, a long silicon crystal (it looked about the size of a pretzel rod, says Tanenbaum) is cut into thin, round slices; the slices are then placed in a furnace. In the furnace, the silicon slices are exposed to a gas containing an impurity, such as aluminum. “At high temperatures, these impurity atoms bombard the crystal surface and slowly force their way into the interior,” the
Bell Laboratories Record
explained. Or to put it another way, the impurities in the furnace atmosphere, depending on the type, could create, on top of, say, an n-type silicon slice, exceedingly thin layers of p-type and n-type silicon stacked on top of one another. One might envision a crystal disc the size of a dime that emerges from a furnace with two thin coatings on top, each less than a thousandth of an inch thick. These are, respectively, the p-type and n-type layers.

Now that he had the right materials, Tanenbaum faced the challenge of actually making an electrical contact with the thin middle p-layer within the diffused silicon disc. That middle layer was far finer than a human hair. He spent weeks on the problem, trying to grind the dime-sized crystal on an angle to attach a wire, and attempting all sorts of other tricks. “Finally, one night, I went back into the lab because my wife was having a bridge game,” he recalls, and by trying a blunt method—in his lab notebook he wrote,
will try direct approach
—he melted an aluminum wire “through” the thin top layer. He made a good contact. It was late on
the evening of March 17, 1955. When he took some instrument readings, he was shocked to see that the device performed better than any germanium transistor then in existence. In his notebook he wrote,
This looks like the transistor we’ve been waiting for. It should be a cinch to make.
“Right away,” he recalls, “I knew that this would be
very
manufacturable.” He drove home like a demon to tell his wife. He could barely sleep, wondering if he had imagined the whole thing, and rushed back to the Labs in the morning to test it. Almost immediately the supervisors were called in, including Jim Fisk, who had returned from the Atomic Energy Commission and was now Bell Labs’ chief of research.

Jack Morton was in Europe, Tanenbaum recalls, but cut his trip short and flew home when he was told the news. Right away Morton—whose opinions on transistor innovation were akin to a final judgment at Bell Labs—understood the potential value. Even Kelly, too busy with management to properly assess the technical details that entered into Morton’s calculus, would defer to him on such matters. If Morton was on board with the diffused silicon transistor, Kelly was, too. That meant the future would be silicon.

D
IFFUSED SILICON
had another use, too.

Fifteen years had passed since the day Walter Brattain had been ushered into Mervin Kelly’s office to regard a strange piece of silicon that had been discovered down in Holmdel, New Jersey. The men had shone a light on the blackened chunk and the resulting electric charge had stunned them. In later years it came to be understood that this chunk of silicon contained a naturally occurring p-n junction where two types of silicon met. The junction is extremely photosensitive. In very general terms, the photons in light are hitting the semiconductor crystal and “splitting off” electrons from their normal location in the crystal; the process, if properly captured, can create a flow of electrons, that is, a flow of electricity.
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Kelly and Brattain and Ohl didn’t know it at the time, but in Kelly’s office the men had been looking at the world’s first crude silicon solar cell.

In the early 1950s, Cal Fuller, who had made the diffused silicon that Morris Tanenbaum used to fashion his silicon transistor, was also working at Murray Hill with the experimental physicist Gerald Pearson. A genial presence at the Labs, slim and handsome and neatly kept, with his dark hair always combed straight back from his forehead, Pearson was Walter Brattain’s old laboratory mate, the same G. L. Pearson who had signed Brattain’s lab notebook on that fateful Christmas Eve in 1947 after Brattain and Bardeen had demonstrated the transistor for the Bell Labs brass. Now Fuller and Pearson were trying to build something with diffused silicon called a silicon power rectifier. In the course of the work on the device, Pearson noticed it was highly sensitive to light.
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Pearson had an old college friend at the Labs named Daryl Chapin, who he knew was trying to develop power sources for remote telephone installations. Often these remote installations—places where phone repeaters might be located, for instance—used diesel generators or dry cell batteries. The batteries had problems in humid weather. Pearson wondered if Chapin might be able to use the power of the sun.

With Pearson as the go-between, the three men—Fuller, Pearson, and Chapin—created over the course of a few months what the Labs eventually called a silicon solar battery. These were thin strips of specially diffused silicon, connected to a circuit, that in sunlight could generate a steady electric voltage. The “battery” was not the first solar cell; functional ones had been made before from the element selenium, for instance. But this was, by Bell Labs’ calculations, “at least fifteen times more efficient than the best previous solar energy converter.”
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That made it the first truly usable solar power device. The batteries promised to last forever, since they had no moving parts. What was striking but almost always overlooked about its invention, Fuller later recalled, was that all three inventors of the device were working in different buildings. “The solar cell just sort of happened,” he said. It was not “team research” in the traditional sense, but it was made possible “because the Labs policy did not require us to get the permission of our bosses to cooperate—at the Laboratories one could go directly to the person who could help.”
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The silicon solar cell generated a hurricane of publicity when it was
unveiled. “The subsequent attention,” Fuller recalled, “which exceeded that of the announcement of the transistor, was unbelievable.”
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By the front-page newspaper headlines,
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one might easily imagine that the cells’ ability to effectively harness the sun meant modern society had reached a pivotal juncture, and that soon enough the world’s energy supplies would be clean and inexhaustible. For those who knew anything about transistors, which had extremely low power requirements and could thus be a perfect match for the new solar technology, the news seemed yet another fantastical bit of Bell Labs augury. On October 4, 1955, a test project for the solar cells was set up by the Labs’ engineers at a remote rural phone installation in Americus, Georgia, 135 miles south of Atlanta. For six months, they powered equipment at the installation, and hinted at the remarkable future where power could be generated anywhere the sun shone.

And then the great excitement of the solar breakthrough dimmed. As Pearson would later recall, the installation was “a huge technical success, but a financial failure.” The solar battery could power the remote telephone equipment with ease. But for the power they generated, the solar cells, at several hundred dollars per watt, simply cost too much.
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In 1956, Daryl Chapin figured that it would cost the average homeowner nearly $1.5 million to buy enough Bell solar cells to power his house.
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By one of Kelly’s fundamental dictums of innovation—something that could do a job “better, or cheaper, or both”—the cost of the cells and the results in Georgia suggested solar power was not going to be a marketable innovation anytime soon. Sometimes, in describing a new invention that seemed technically brilliant but impractical, industrial scientists would quip that they had found “a solution looking for a problem.” The silicon solar cell needed a problem, as yet unimagined, to appear.

T
HE PUBLICITY AROUND
inventions like the solar cell tended to distort public perceptions about the actual work being done inside the Labs. Kelly would often point out that the Labs workforce—including PhDs, lab technicians, and clerical staff—by the early 1950s totaled around nine
thousand.
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Only 20 percent of those nine thousand worked in basic and applied research, however. Another 20 percent worked on military matters. Meanwhile, the rest of the Labs’ scientists and engineers—the majority—toiled on the never-ending job of planning and developing the system. Their work was arguably less glamorous. The research scientists at the Labs were thinking ahead to a glorious future that was ten or even twenty years away. The development and systems engineers were thinking about what they could do in the next year or two or three. And yet the projects undertaken by the latter group during Kelly’s presidency were in many ways just as ambitious as those done in research; one might see that they were logistically more difficult. In development, mistakes were not excusable. Building a new product or invention, and then putting it into the working telephone system, demanded perfection.

Systems engineers—the ones who looked at new ideas and decided whether they could improve the system—lived by Kelly’s rule:
Better, or cheaper, or both
. In the years immediately following the war, one idea that met with their approval involved a project whereby the Labs, working in conjunction with AT&T’s Long Lines Department, could ease the congestion on the long-distance phone network. The plan was to create a new, long-distance corridor that would forsake cables altogether—in effect, it would be wireless. At the time, all long-distance calls, along with some coast-to-coast TV transmissions, were carried on thick underground coaxial cables that crisscrossed the country. But it was believed that a nationwide chain of microwave relay antennas, linked to one another in a relatively straight line, could efficiently move calls and programs great distances. Indeed, the microwave links would liberate the phone company from the onus of buying and burying or stringing more of its expensive cables. To test the idea, “an eight-hop route,” as the
Bell Laboratories Record
described it—with seven antenna stations along a 220-mile corridor—was built in the late 1940s. The test route linked New York with Boston, via eight microwave towers, some built from concrete blocks and others from steel girders, most located on hillsides (or in some cases on tall urban buildings), topped by special horn-shaped antennas, vaguely resembling megaphones, which had been invented at
Bell Labs largely under the direction of Harald Friis, the head of Bell Labs’ Holmdel, New Jersey, research office.
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Usually, two horn-shaped antennas on the towers would receive calls; a repeater apparatus inside the tower would amplify them; and then two other horn-shaped antennas, facing the opposite way, would instantly relay them to the next tower in the phone link. The height of these towers was crucial: Transmissions by microwaves traveled in straight lines and required a clear line of sight. Any interruptions—buildings, trees, mountains—would affect the signal.

When the local test proved successful, AT&T and Western Electric built a national system of microwave links, requiring the construction of 107 towers across the United States, or about one every thirty miles. A phone call could now be handed off automatically—that is, received and immediately resent—between towers in some of the most remote locations imaginable. For instance, a long-distance call made from a Manhattan advertising agency could be switched through the network to a microwave tower atop a New York skyscraper; from there it could move from east to west at nearly the speed of light, passing from station to station—through a 406-foot steel tower in Des Moines, for instance, and another installation high atop Mount Rose, in Nevada—before ultimately arriving at a receiving station perched high in the Oakland hills east of San Francisco, where it would be routed to a switching center and tied into the local phone exchange.

“Mark, how are you?” an AT&T vice president in New York asked Mark Sullivan, president of Pacific Bell, in San Francisco, during a call on the system’s opening day in August 1951.

“It’s nice to hear your voice,” Sullivan said. “I’m fine, thank you.”
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This exchange of dull pleasantries seemed fitting for the occasion. In contrast to the opening of the first transcontinental line some thirty-five years before, the relay system produced only a slight riffle of excitement, suggesting that the public had come to take for granted easy coast-to-coast communications. Microwave towers would shape the future of telecommunications, as well as the fate of Bell Laboratories. But at this point, nobody could see how.

O
ne project under Kelly’s direct supervision captured the public’s imagination, and expanded the system’s reach, in a way that microwave towers could not. The project was given the name TAT-1; it was the first transatlantic phone cable, a joint project of AT&T and the British Post Office, that was intended to carry thirty-six phone conversations at any given time from the tiny village of Clarenville in Newfoundland, Canada, to the city of Oban, Scotland. Actually, TAT-1 was two cables that would be laid side by side. One cable would carry voices to Europe, the other would carry responses back.

Sending a message over land had always been easier than doing so over or under the water. Engineers had first tried to connect North America to Europe in the 1850s, when successive attempts were made to lay down a telegraph cable on the floor of the North Atlantic. “It was a mathematical impossibility to submerge the cable successfully at so great a depth, and if it were possible, no signals could be transmitted through so great a length,” the British royal astronomer predicted at the time.
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Indeed, the first two tries had ended in failure; the cable layings, done by way of a sailing ship outfitted with a giant spool of copper wire in its hold, were deemed perilous, multimillion-dollar disasters. Cables would
snap, snag, kink, and leak; ocean storms would batter the crews and equipment; and in the end, transmissions on the line might work for a couple of weeks before going dead for no apparent reason. But in 1866, a cable—made of better materials, and laid down with more care and expertise—finally succeeded in carrying dots and dashes back and forth between Canada and Ireland. And in the decades after, engineers figured ingenious ways to increase the speed and capacity of other submarine cables. By the early 1900s, overseas telegraph communications had become a lucrative business.