Why is the CPU only made of silicon instead of germanium, which consumes less energy?

In 1883, the great inventor Edison was racking his brains to improve the carbon filament electric lamp he invented before, because carbon filament evaporates too easily. One day, he suddenly thought: Putting a copper wire in the bulb may prevent the carbon wire from evaporating and prolong the life of the bulb. As a result, the experiment failed again, and the carbon filaments still evaporated completely. However, he discovered a strange phenomenon from this failed experiment. There was actually a weak current passing through the copper wire. It's weird! Copper wire and carbon wire are not connected, where does the current come from? Physics at the time could not explain this problem. Edison, a business-minded person, immediately applied for a patent, named the "Edison Effect", and then went on to improve his electric light.

Edison and his light bulb. Later, it was known that this was due to heat excites electrons. British physicist Fleming invented the world's first diode electron tube based on the "Edison effect". Since the tube generally needs to be vacuumed, it is also called a vacuum tube. Later, the impoverished American inventor De Forest, cleverly added a grid between the filament and the plate of the diode, thus inventing the first vacuum triode. This kind of magical tube can amplify electronic signals and prevent weak signals from being lost. It is more like a gate that only allows current to flow in one direction so that electrons will not flow back into the circuit. You can think of it as a flush toilet. If the sewer is not one-way, how should we live? This immediately opened up the spring of electronics, and DeForest said: "I found an invisible empire in the sky!" At the earliest, the development of electronic tubes drove radio communications, and a large number of radio stations appeared quickly like wildfires. In all parts of the world. However, this is only the beginning!

De Forest, known as the "Father of Radio". In New Jersey, USA, just a few miles away from Edison's invention factory, there is a laboratory that is the most famous (no one) in the world-Bell Labs, where eight Nobel Prize winners were born. In 1945, after World War II, Shockley, a physicist at Bell Labs, planned to use silicon to create an amplifier that would replace electron tubes. At that time, all engineers had to use electron tubes, but they all hated them because their glass shells were long, brittle, bulky, and easy to overheat.

The best laboratory in history: Bell Labs. Shockley knows very well that semiconductors are the key to solving problems. Only semiconductors can achieve the balance that engineers expect. On the one hand, they allow enough electrons to pass through to form a loop without losing control on the other. It turned out that he was very far-sighted. He chose silicon as the electron tube. Unfortunately, several experiments failed. Two years later, there is still not much progress. Shockley has more important things to do. He threw the new transistor project to two subordinates: Budding and Bratton.

The ambitious Shockley Barding and Bratton are a good pair. Badin’s hands-on skills are poor, and Bratton is an excellent engineer. In many cases, it’s Badin who comes up with ideas, and Bratton rushes. Execute to the first line. After receiving this project, the two quickly found the crux of Shockley: Silicon is too brittle and difficult to purify. So they took out the periodic table of the elements to see what other elements were similar to silicon, and they saw germanium at a glance. Compared with silicon, germanium has a higher energy level of outer electrons, so outer electrons are easier to contribute and have better conductivity. Soon, in 1947, the world’s first transistor was born, made of germanium.

The world's first transistor was born in Bell Labs. At this time Shockley returned from a business trip in France and returned to this project, making him look like a leader. In 1956, the three of them won the Nobel Prize in Physics together. This matter is very meaningful. You must know that the Nobel Prize in Physics is selected by the Royal Swedish Academy of Sciences. Their tastes are more inclined to pure scientific research than technological development. . The Nobel Prize for the invention of the transistor in 1956 represented their recognition of applied science. Facts also proved that their vision was very strong, and the transistor did change the world later. Budding and Bratton are top R&D engineers, but they are too shy. It is said that at the Nobel Prize ceremony, they were so nervous that they had stomach cramps, and they were speechless when facing the King of Sweden. On the contrary, Shockley is a boss who wants to do whatever he wants. He drove Barding to another project, and he took the results of germanium transistors as his own. The Bell Labs team came to an end like this, and there were no new inventions.

Bell Labs completed the technical feasibility, and the industrialization was completed by the "Texas Instruments" company. At that time, germanium transistors were successfully developed, and the processing power of computers was improved by several orders of magnitude compared with that of the electron tube era, and the germanium transistors were also used in daily appliances such as radios. But germanium is too scarce after all, and the high price makes all engineers look at silicon again. Germanium is indeed very conductive, but it also generates unnecessary heat, causing the transistor to overheat and shut down. More importantly, silicon is cheap. In 1954, at an exhibition in the United States, Gordon Teal, an engineer from Texas Instruments, took the stage and changed his tricks. He threw a germanium transistor connected to the record player into a bucket of hot oil, and the record player was immediately silenced. Then he removed the germanium transistor, replaced it with his own silicon transistor, and threw it into the oil drum, the music of the record player continued. His advertisement was a big success and he signed numerous orders on the spot. Since then, germanium has been abandoned by transistors.

Gordon Teal, engineers must also show magic. In 1958, "Texas Instruments" ushered in a new employee. He spoke slowly and was always unsmiling. He found that his new company had a large group of low-income female workers who were wearing protective clothing and sweating every day. While looking at the microscope, they grumbled and welded tiny silicon components together. Sometimes, the thin wires are accidentally broken, and the previous work is wasted. Engineers can't do anything about this, because computer hardware is developing faster and faster, and they always have to make the hardware more complex, which requires more transistors.

What the women workers do every day is to solder these transistors together. One hot summer, all the employees of the company went out for vacation. Kilby came to the workbench by himself. The rare tranquility made Kilby contemplate. It is too stupid to spend thousands of people to solder transistors. Why can't all the parts be carved on a semiconductor? Kilby immediately began to act. He calculated it and felt that the purity of silicon was not enough to make the resistors and capacitors he needed, so he chose germanium. Soon, he succeeded. He described his invention like this: "In the body of a semiconductor material, all the constituent circuits seem to be independent, but they are all highly integrated!" Therefore, his new gadget is called: " integrated circuit".

The first integrated circuit invented by Kilby now looks a bit low. Just like last time, germanium was married again. Only half a year later, Noyce of Fairchild in the United States invented silicon-based integrated circuits. Kilby's germanium integrated circuits can only lie in the museum. In a highly competitive market, capitalists will choose cheap silicon without even thinking about it. Fortunately, Kilby has not been forgotten. In the field of computer hardware, many latecomers still regard him as the first idol. Until now, the CPU we use is still based on his design. In 2000, he finally got his reward: the Nobel Prize in Physics. Unfortunately, germanium seems to have been completely forgotten. The global information industry talents are concentrated in Silicon Valley, and no one mentions the "germanium valley". Although the germanium element played a pioneering role in the two technological development periods, it gave the glory to silicon, which can be called the darkest element. Is it just because it is scarce, is this also its fault?