Recently, when I was studying the computing power sector, I took a look at the hard-core link behind semiconductor production - the clean room. This thing sounds like a "very clean room", but in practice, it is far more complex than you think.

**Air cleanliness: 10,000 times cleaner than an operating room**
The chip process has been rolled up to 3 nanometers, and the standards of the clean room have also been rolled to outrageous. Now the top is called "ISO Level 1", and there can be no more than 10 particles larger than 0.1 microns per cubic meter of air. What concept? This particle starts in the millions of particles in the outdoor air, and the cleanroom requires **hundreds of thousands of times** purity.

Why is it so perverted? Because a 0.1 micron dust falls on the chip, it can directly scrap the circuit - either short circuit or break, and the yield rate instantly collapses from 85% to 30%. Producing a high-end chip would have burned money, and then it would be scrapped because of dust, which would really throw money into the water.

**Temperature and humidity control: 0.1°C error is too much**
The temperature should be locked at about 22°C, and the fluctuation in the core area should not exceed **±0.1°C**. This is not a joke, the thermal expansion and contraction of the silicon wafer, the temperature difference of 1°C can make it expand by 0.24 microns, the lithography machine is not aligned, and the entire wafer is directly invalidated.

The humidity is also stuck at 45% ±5%. If it is too wet, the static electricity cannot be dissipated, and the dust will be sucked up; If it is too dry, static electricity will fly around, and it may directly break down the circuit. Therefore, the whole workshop must be equipped with a bunch of high-precision sensors, 24-hour monitoring and adjustment, and there is no room for sloppiness.

**Airflow and pressure difference: Air must also be "obedient"**
The air in the clean room is not turbulent, but vertically one-way flow - 0.45 m/s blows from the ceiling to the ground, bringing all the dust to the return air outlet. The pressure difference between different areas must be maintained, and the pressure in the core area is the highest, decreasing layer by layer to ensure that the air always flows from the clean place to the dirty place, and the pollutants are poured backwards? Inexistent.

**Micro-vibration control: even earthquakes are protected**
How sensitive is the lithography machine to vibration? The RMS value (root mean square of vibration velocity) is ≤ 1 micron per second, and the most stringent areas must reach VC-E level. To do this, the entire clean room had to be built on a separate raft with an air spring isolation system. Opening a machine in the workshop next door may affect the chip yield.

**Electrostatic Protection: The Human Body is a Walking ESD Bomb**
A casual friction on a human body can generate thousands of volts of static electricity, and the chip cannot withstand a voltage of more than 100V. Therefore, the staff must be equipped with anti-static equipment: anti-static flooring, dust-free clothing, bracelets, and ion fans must be installed in the workshop to neutralize static electricity. This combination of punches can compress the electrostatic voltage to a safe range.

**Ultrapure water + ultrapure gas: Even water and air must be "purified"**
The resistivity of the water used for production is ≥ 18.2 trillion ohms centimeters (close to absolute pure water), and the gas purity ≥ 99.999% (five nines). A little bit of impurity will affect the chip performance.

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**Industry prospects: AI computing power is exploding, and clean rooms are also soaring**
Recently, the demand for computing power for AI training and cryptocurrency mining has skyrocketed, which has directly led to the expansion of semiconductor production capacity. Global cleanroom investment is expected to be 194.3 billion yuan in 2025, with the Chinese market accounting for 58.3 billion yuan.

The threshold for high-end clean room projects is extremely high - large investment, short construction period, and low fault tolerance rate, so the industry concentration is very high and the leading enterprises are sticky. There are two main growth points in the future:
1. **Domestic substitution acceleration**: China's chip self-sufficiency rate is only 16.7% (2021 data), there is huge room for import substitution, and policy support is also increasing.
2. **Technology iteration driven**: The more advanced the process, the higher the standard of the clean room, and the cost per square meter will also rise. The upgrading and transformation of old production lines is another wave of continuous demand.

In short, the semiconductor clean room has deep technical barriers and fierce capital expenditure, but the market cake is big enough. For investors who pay attention to the computing power sector, these "hidden champions" in the upper reaches of the industrial chain are also worth taking a closer look.