The semiconductor industry’s dryness requirements for compressed gas
In the high-tech field of semiconductor manufacturing, the dryness requirements of compressed gas are extremely strict, and its standards are higher than ordinary industrial scenarios. The following is an analysis from three aspects: technical requirements, implementation methods and potential risks:
1. Core standards for dryness
The requirements for compressed gas dryness in semiconductor processes usually need to be met Pressure dew point below-40℃, some key processes (such as lithography, etching) and even require Below-70℃。This indicator means that the moisture content in the gas needs to be controlled to ppm level, almost completely dry to prevent any potential contamination of the wafer.
2. Drying realization method
Semiconductor factories pass Three-level deep processing Ensure compressed air dryness:
- Source control of oil-free air compressor
Adopt oil-free lubricated air compressor to completely eliminate oil pollution and comply with ISO 8573-1 Class 0 standard. - Adsorption dryer deep water removal
Use adsorbents such as molecular sieves to reduce the dew point of compressed air to below-70℃ to ensure that the moisture content approaches zero. - Terminal filtering and real-time monitoring
A 0.01μm precision filter is installed at the end of the gas supply, and it is coordinated with a dew point meter for 24-hour monitoring. Once the humidity is found to exceed the standard, the system will automatically trigger the drying equipment to strengthen operation.
3. Serious consequences of insufficient dryness
If the dryness of the compressed air fails to meet the standard, it will cause triple risks：
- Equipment corrosion and shortened life
Moisture reacts with metal pipes and valves, accelerating oxidation and corrosion, and increasing equipment failure rates. - Process accuracy failure
- A water film forms on the surface of the wafer, causing distortion of the lithography machine’s projection and deviation of the etch line width from the design value.
- The risk of electrostatic discharge (ESD) has increased sharply, directly breaking down nanoscale transistor structures.
- The yield rate dropped like a cliff
Moisture reacts with photosensitive components in the photoresist, causing pattern defects; residual water molecules evaporate in the vacuum chamber, contaminating the entire batch of wafers.
4. Industry practice cases
An incident occurred in a global Top 5 wafer factory where the compressed gas dew point rose to-35℃ due to a dryer failure, causing a trigger 2000 12-inch wafers scrapped, direct economic losses exceed US$2 million. Since then, the plant has upgraded the drying system to a dual adsorption tower redundant configuration and added a backup dew point monitoring loop to ensure that any single point failure can be quickly switched to the backup system.
conclusion: Semiconductor industry approved Oil-free compression + deep adsorption drying + terminal precision filtration Combined with real-time dew point monitoring, it builds an iron wall for compressed gas quality control. This standard not only ensures the stable operation of equipment, but also is the key support for the chip yield from 95% to 99%.
