Semiconductor oil-free air compressor adopts water-lubricated air compressor

The semiconductor industry is undoubtedly an industry that needs to break through the technological blockade in the next 10 years. In the global semiconductor industry, the development of the domestic semiconductor industry is relatively late. In the process of gradually breaking through the technological blockade in various industries, semiconductor companies are also gradually expanding the scale of the industry. In the semiconductor industry, the "oil-free compressed air" of the "water-lubricated air compressor" It is an important role in development.

The gases commonly used in the semiconductor industry, such as carbon dioxide, argon, nitrogen, etc., water lubricated air compressor can compress a variety of special gases, there is a need to call us "Shanghai Granklin Group".

what is a semiconductor?

First, let's talk about semiconductors. From the point of view of the material: semiconductor refers to the material between the conductor and insulator at room temperature. Like copper wire in daily life, aluminum wire is a conductor, and rubber is an insulator. From the point of view of conductivity: semiconductor refers to a controllable conductivity, ranging from insulator to conductor.

Four characteristics of semiconductors:

the discovery of semiconductors can be traced back to 1833. Faraday, the father of British scientists and electronics, first discovered that the resistance of silver sulfide varies with temperature, which is different from that of ordinary metals. This is the first discovery of semiconductor phenomena.

Faraday

but the summary of the characteristics of semiconductors was not completed by Bell Labs until December 1947.

The resistance of a semiconductor decreases as the temperature rises, but in general, the resistance of a metal increases as the temperature rises.

Photovoltaic effect: The junction formed by the contact of a semiconductor and an electrolyte produces a voltage when illuminated.

Photoconductive effect: semiconductor in the case of light, will increase the conductivity.

Rectification effect: The conductivity of semiconductors is directional and is related to the direction of the applied electric field. A forward voltage is applied across the semiconductor and it conducts; if the polarity of the voltage is reversed, it does not conduct.

The original king is not silicon

in the early days of semiconductor chips, silicon was not the protagonist, germanium was. The first transistor is a germanium-based transistor, and the first integrated circuit chip is a germanium chip.

germanium

the first transistor was invented by Bardin and Bratton. They invented the bipolar transistor (BJT). The first P/N junction diode was invented by Shockley. Moreover, the junction type designed by Shockley immediately became the standard structure of BJT and has been in service ever since. The three of them also won the Nobel Prize in Physics that year in 1956.

Shockley, Barton, Bratton

A transistor can be simply understood as a miniature switch. According to the characteristics of a semiconductor, an N-type semiconductor can be formed by doping phosphorus in a semiconductor, and a P-type semiconductor can be formed by doping boron. The combination of N-type semiconductors and P-type semiconductors forms an important structure in electronic chips-PN junctions; this allows specific logical operations (such as AND gates, OR gates, NOT gates, etc.)

however, germanium has some problems that are very difficult to solve, such as many interface defects in semiconductors, poor thermal stability, and insufficient oxide density. Moreover, germanium is a rare element, the content in the earth's crust is only 7 parts per million, and the distribution of germanium ore is very scattered. It is precisely because germanium is very rare and unconcentrated that the raw material cost of germanium remains high; rare things are expensive, the raw material cost is high, and germanium transistors are not much cheaper, so germanium transistors are difficult to produce on a large scale.

So, the researchers, will study the gaze to jump up a level, fancy silicon element. It can be said that all the congenital defects of germanium are the inherent advantages of silicon.

Silicon is the second most abundant element after oxygen, but you basically can't find silicon in nature. The most common compounds are silicon dioxide and silicates. And silicon dioxide is one of the main components of sand. In addition, feldspar, granite, quartz and other compounds are based on silicon-oxygen compounds.

The thermal stability of silicon is good, with a dense, high dielectric constant oxide, can be easily prepared with few defects in the interface of silicon-silicon oxide interface.

Silicon oxide is insoluble in water (germanium oxide is soluble in water), and insoluble in most acids, which is almost the same as the corrosion printing technology of printed circuit boards. The product of the combination is the integrated circuit plane process that continues to this day.

silicon crystal column

upper history of silicon

entrepreneurial failure: It is said that Shockley saw that no one had successfully made silicon transistors at that time, and there was a huge market opportunity; so in 1956, he left Bell Labs and went to California to start his own company. Unfortunately, Shockley is not a good entrepreneur, and his level of business management is a fool compared to his academic level. So Shockley himself did not fulfill his ambition to replace germanium with silicon, and the stage for the rest of his life was the podium at Stanford University. One year after its establishment, the eight talented young people he recruited collectively defected him, and the ambition of silicon to replace germanium will also be completed by the "eight traitors.

The rise of silicon transistors

before the "Eight Renegades" founded Fairchild Semiconductor, germanium transistors were the absolute mainstream of the transistor market. In 1957, nearly 30 million transistors were manufactured in the United States, only 1 million silicon transistors and nearly 29 million germanium transistors. With a market share of 20%, Texas Instruments has become a giant in the transistor market.

Eight Renegades and Fairchild Semiconductor

the U.S. government and military, the largest customers in the market, want to use chips in rockets and missiles to increase the precious launch load and improve the reliability of control terminals. But the transistor will also face high temperature, severe vibration caused by the harsh working environment.

In terms of temperature, germanium was the first to fail: the temperature that germanium transistors can withstand is only 80 ℃, while the military's requirement is to operate stably at 200 ℃. Only silicon transistors can withstand this temperature.

Conventional silicon transistors

fairchild invented the manufacturing process of silicon transistors, making the manufacture of silicon transistors as simple and efficient as printed books, and much cheaper than germanium transistors in terms of price. The production process of Fairchild's silicon transistor is roughly as follows:

first of all, draw the layout diagram by hand, which is sometimes large enough to occupy a wall, and then take the diagram down and reduce it to a small light transmission sheet. There are usually two or three light transmission sheets, each representing a layer of circuit;

secondly, a layer of photosensitive material is coated on the polished silicon wafer, and the circuit pattern on the transparent sheet is projected onto the silicon wafer by ultraviolet/laser;

third, the dark areas and lines on the light transmitting sheet will leave unexposed patterns on the silicon wafer, and these unexposed patterns will be cleaned with acid, and then semiconductor impurities (diffusion technology) will be added, or metal conductors will be plated;

fourth, repeat the above three steps for each light transmitting sheet, and a large number of transistors can be obtained on the silicon wafer, which are cut by female workers under a microscope and then connected with wires, which are then packaged, tested and sold.

With the large number of silicon transistors on the market, Fairchild, founded by the Eight Renegades, has become a company that can stand side by side with giants like Texas Instruments.

An Important Pusher-Intel

really sum up the dominance of germanium, or the subsequent invention of integrated circuits. At that time, there were two technical routes, one was the integrated circuit of the germanium wafer of Texas Instruments, and the other was the integrated circuit of the silicon wafer of Fairchild. At first, the ownership of the two patents on integrated circuits was very fierce, but after that, the patent office acknowledged the ownership of the two patents on integrated circuits.

However, because Fairchild's technology is more advanced, it has become the standard of integrated circuits and continues to be used so far. Later, the inventor of the integrated circuit-Noyce and the author of Moore's Law-Moore left Fairchild Semiconductor, by the way, they were all members of the "Eight Renegades. Together with Grove, they created what is now the world's largest semiconductor chip company, Intel.

In the subsequent development, Intel pushed silicon chips. He has defeated Texas Instruments, Motorola, IBM and other giants to become the king of semiconductor storage and CPU.

As Intel became the dominant industry, silicon also completely ended germanium, once the Santa Clara Valley, also known as "Silicon Valley". Since then, in the public's understanding: silicon chip is equal to semiconductor chip.

Although germanium is withdrawn from the chip field, it is still an important semiconductor material and still has an irreplaceable position in other fields.

Summary:

silicon can replace the dominant position of germanium on the chip and become the main material for the preparation of semiconductor chips. Not only in the physical and chemical properties of silicon, as well as the advantages of reserves; also lies in people's continuous pursuit of technological innovation.