32. Germanium: Harder, Better, Faster, Stronger

Silicon gets all the press, but germanium was the real trailblazer of the Information Age.

Featured above: One of Bell Lab’s publicity photos promoting the transistor, featuring John Bardeen, Walter Brattain, and William Shockley. “Boy, Walter hates this picture,” Bardeen told a reporter several years later. “That’s Walter’s apparatus and our experiment, and Bill didn’t have anything to do with it.’ “

Show Notes

Germanium was the second of Mendeleev’s predictions to come true, after gallium. If any doubt in Mendeleev’s periodic table after gallium, germanium squashed it.

As for neptunium, Herman’s discovery turned out to be some improperly identified niobium, so the name was freed up again a few years later when the element in between uranium and plutonium needed a name.

I couldn’t really get into exactly how transistors work, as it’s a little beyond the scope of this short episode. It also benefits from some visual aid. Once again, Veritasium does a good job explaining it for us:

The “traitorous eight,” as Shockley called them, went on to become giants in the field — as close to household names as electronics can become, including Gordon Moore, the founder of Intel.

Episode Script

When studying history, the point at which any story begins or ends is largely a matter of perspective. For instance: Germanium was discovered in 1886 by Clemens Winkler, but its existence was predicted by Dmitri Mendeleev about fifteen years earlier.

He called the element “eka-silicon,” because he knew it would occupy the space beneath silicon in Group 14, but that was merely a placeholder name. True naming rights belonged to whomever first chemically isolated an element in the lab, and Winkler was amused by a recent parallel in another of the sciences: Like element 32, the planet Neptune’s existence had been predicted decades before anyone ever saw it through a telescope. Winkler sought to name his own discovery “Neptunium” in celebration of this little coincidence — but sadly, the Russian chemist R. I. Herman had just taken that name for his own, entirely unrelated discovery.

So Winkler took a page out of de Boisbaudran’s book and lent the new element the Latinized name of his homeland: Germania.

Of course, that means the prologue to germanium’s story could include the entire Franco-Prussian War and unification of the German states, which is a just little too complex for the intro segment of this podcast.

The point is, Sometimes, a prequel can be just as interesting as the main story. When it comes to the blockbuster tale of semiconductor electronics, the name of that prequel is germanium.

You’re listening to The Episodic Table Of Elements, and I’m T. R. Appleton. Each episode, we take a look at the fascinating true stories behind one element on the periodic table.

Today, we’re lowering our resistance to germanium.

We discussed electronics the last time we visited Group 14 — it’s hard not to when the subject is silicon. But we didn’t have much time to get into the pre-silicon history of electronics.

The dawn of electronics was heralded by the invention of the vacuum tube. This device could manipulate an electrical current in several ways. It could amplify an electrical signal, or convert a current from AC to DC. But perhaps most groundbreaking was its ability to precisely control the flow of electricity by acting as a gate, or a switch. Depending on whether certain conditions are met, the tube can permit the flow of electricity in an “on” state, or switch off and break the circuit.

This simple mechanism provides the basis for all modern computers. When we say that our electronic devices speak in a language of zeroes and ones, this is what we’re talking about. “Zero” indicates a switch that’s off, while “one” indicates a switch that’s on. And everything can be translated into a series of zeroes and ones — from the simplest mathematical equation to sonorously spoken stories of science.

Of course, it requires an enormous number of switches to perform these tasks, especially as they grow more complex. One of the world’s first general-purpose computers, ENIAC, employed well over 17,000 vacuum tubes to carry out its assigned tasks — tasks that are laughably simple by modern standards.

There’s a very obvious practical problem with such a setup: 17,000 glass vacuum tubes take up a lot of space, and they’re pretty delicate, to boot. If you’ve ever wrestled with a tangled string of Christmas lights, you have a rough idea of how frustrating it can be to repair such a machine. ENIAC and machines like it were famously gargantuan, taking up entire rooms and weighing dozens of tons.

By the 1940s, it was clear that for the field to progress, it needed to move beyond bulky glass bulbs. No one felt this more urgently than William Shockley, a physicist at Bell Labs. He came up with the idea of the solid-state transistor: A device that could switch on or off like a vacuum tube, but had no moving parts. This would make it faster, smaller, more efficient, and much less prone to breakage.1

But Shockley couldn’t figure out how to build the thing. His best attempt involved “a small cylinder, coated thinly with silicon,”2 but practice never bore out the theory. He recruited a handful of scientists to help tackle the problem, most notably John Bardeen and Walter Brattain. Even on this team of legendary chemists, physicists, and engineers, Bardeen was renowned as the brains of the operation. Meanwhile, Brattain was the man with the magic hands, able to build just about anything. Shockley performed the imperative task of supervising the team, often from a distance as he attended lectures and conferences overseas.

Left to their own devices, Bardeen and Brattain got along famously and made steady progress on the problem. By December 1947, they had learned enough to construct a working prototype of the solid-state transistor. Critically, they tossed out Shockley’s silicon cylinder in favor of germanium — as we mentioned in episode 14, germanium possesses some electrical qualities that make it easier to work with for this purpose. The two unveiled their invention — and Shockley was furious.3 4

The duo might have used Shockley’s original research as a jumping-off point, but they had clearly advanced much further on their own. Additionally, on the day when Bardeen and Brattain revealed their work, Shockley was in Paris for the Christmas holiday, highlighting just how out-of-the-loop their supervisor was.5

Shockley ran back home, and the man who had been so conspicuously absent from the lab for years was suddenly making his presence very known. Since this whole project was his idea, he figured, he deserved all the credit.

When he returned to Bell Labs, he went straight to the lawyers, and ensured that his name would be the only one to appear on U.S. Patent No. 2502488, “Semiconductor Amplifier.” Whenever a photo was taken for publicity, Shockley made sure he was in front of the camera. And finally, he split up the dynamic duo, sending Bardeen off to work in an entirely different building on unrelated projects. Shockley then locked himself inside a Chicago hotel room for four straight weeks until he drew up schematics for an even better transistor.

Shockley effectively ruined any relationship the three men had. Bardeen left Bell Labs not long afterward. Brattain remained, but refused to report to Shockley anymore.

Bardeen and Brattain remained friends, occasionally meeting up for a round of golf even as their careers went in separate directions. But they understandably kept their distance from Shockley until 1956, when all three were summoned to Stockholm, where King Gustaf VI of Sweden jointly awarded them the Nobel Prize in Physics.

So Shockley got exactly what he wanted. But that didn’t make him a better person. The same year they won the Nobel Prize, Shockley founded his own semiconductor company.  It was barely up and running for a year before eight of his top scientists resigned in protest of his tyrannical personality. The company limped along for a few years after that, but it never brought a single product to market, and was finally shuttered in 1968.

Today, Shockley Semiconductor is widely regarded as the birthplace of Silicon Valley. Considering it was a foolhardy endeavor fueled more by ego than ideas, that seems like an appropriate designation.

And somehow, by the time he died, Shockley’s reputation had little to do with his Nobel Prize or Silicon Valley. He spent the rest of his life as a fierce proponent of eugenics, and spouted such overtly racist rhetoric so passionately that the issue took up half of his lengthy obituary in the New York Times.6

Regardless of the personalities involved, the transistor was a revolutionary invention — one of the most important of the twentieth century. Pretty much every electronic device that’s ever made its way into consumers’ homes — and there are a lot of them — only exists because of the transistor.

But while the gents at Bell Labs invented the transistor, they didn’t perfect it. For years, computer chips were knotted messes of solder and wire. Much like the old vacuum tubes, these were delicate, and prone to failure. And while the shift from glass tubes to solid-state transistors allowed for more complex circuitry, computers were being called upon for increasingly difficult tasks… which meant even more complex circuitry. It was a problem that hardware engineers called “The Tyranny of Numbers.”

Enter Jack Kilby, who was a rookie engineer at Texas Instruments in 1958. He arrived at the TI campus in the middle of the summer, just as literally every other employee was going on vacation. So he had a lot of free time to work on whatever his heart desired.7

He had an idea to change how computer chips were built from the ground up. Rather than take a bunch of separate components and solder them together, he thought, why not start with one big block of material and carve the circuit into it?

Silicon chips were commonplace by that time, but for this experiment, Kilby didn’t want to take any unnecessary risks. He went back to the ol’ reliable of semiconductors: germanium. It took a little while to work out all the kinks, but by September of that year, Kilby had built a complete working circuit out of a single slab of germanium. It eliminated the many thousands of potential points of failure, reduced heat and power consumption, and allowed for a much smaller design. In short, it was superior in every way.8

Kilby called his design the integrated circuit. Colloquially, people called it the microchip.

Surprisingly, this breakthrough didn’t take the world by storm. It amused other scientists on the lecture circuit, but that was about it. So, largely in an effort to show off the practical value of the microchip, Kilby designed the pocket calculator — as powerful as a desktop computer, but a fraction of the size.

Kilby received the 2000 Nobel Prize in Physics for his contributions, and for once, the honor wasn’t mired in controversy. And microchips only became smaller and more powerful. In 1965, Intel co-founder Gordon Moore famously predicted that scientists would double the number of transistors they could fit on a microchip every eighteen months. That became known as Moore’s Law, and it was more or less accurate through the end of the twentieth century.

We’re now at a point where whatever device you’re using to listen to this podcast almost certainly holds billions of individual transistors, some of them no larger than fifty atoms across, on a processor that’s conducting millions of operations per second. If a typical mobile phone were built using vacuum tubes rather than microchips, it would be the size of the Hindenburg.9

We’re now at a point where if scientists try to build transistors any smaller, quantum effects start interfering with their operation. It’s the latest obstacle hardware engineers need to break through if microelectronics are to advance. In the meantime, companies like Intel and Texas Instruments are focusing on decreasing processors’ power consumption, rather than increasing their speed. Germanium tends to play second fiddle to silicon in the semiconductor industry these days, but who knows? It’s been the battering ram scientists used to break down walls in the science of electronics twice before. Perhaps it’s just waiting to come out of mothballs to break down this one, too.

You can find Jack Kilby’s original germanium microchip in the Smithsonian Museum, in case you weren’t convinced of element 32’s esteemed place in the history of semiconductors, and you can be sure that it’s of very high purity. The only problem is, the museum staff won’t let you take it home to add to your collection.

Germanium isn’t completely absent from modern electronics. It’s used in LEDs and some processor chips, but it’s more often appreciated for its unique properties. In the same way that beryllium is completely transparent to x-rays, infrared light passes straight through germanium as though it were clear glass. Any kind of infrared camera you can buy almost certainly relies on a high-purity sample of element 32.10

In fact, because of these specialized uses, any germanium you get your hands on is likely to be pretty pure. That might not be the main reason so many people invested so much time and money into researching germanium, but it is a nice side effect.

Thanks for listening to The Episodic Table of Elements. Music is by Kai Engel. To learn why the neptunium discovered by R. I. Herman wasn’t the neptunium on the periodic table, and how William Shockley did even further damage to his own reputation, visit episodic table dot com slash G e.

Next time, we’ll get off our lazy arsenic.

Until then, this is T. R. Appleton, reminding you that much like the microchip, Marvel’s Ant-Man also grows more powerful as he shrinks, until he encounters serious trouble in the Quantum Realm.

Sources

  1. American Physical Society, John Bardeen, William Shockley, Walter Brattain. Alaina G. Levine.
  2. PBS.org, Transistorized! This verbatim description of Shockley’s first attempt is replicated in all sorts of media, but it all seems to point back to this source.
  3. PBS.org, Transistorized! Shockley, Brattain, Bardeen.
  4. IP Watchdog, Evolution of the Transistor. Steve Brachmann, April 3, 2017.
  5. The Disappearing Spoon, p. 40-44. Sam Kean, 2010.
  6. The New York Times, William B. Shockley, 79, Creator Of Transistor And Theory On Race. Wolfgang Saxon, August 14, 1989.
  7. All About Circuits, Jack Kilby And The World’s First Integrated Circuit. Tim Youngblood, September 16, 2017.
  8. Texas Instruments, The Chip That Jack Built.
  9. This is a really rough calculation assuming a volume of 75ml per vacuum tube, with some assistance from Wolfram Alpha.
  10. PeriodicTable.com, Germanium. Theodore Gray.

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