Grade of compressed air in semiconductor enterprises

In semiconductor companies, the classification of compressed air is extremely strict and needs to be met at the same time. Cleanliness, chemical purity and stability requirements, its core grade standards and basis are as follows:

1. core standard system

1. ISO 8573-1:2010 (Compressed air impurity level)
   • oil content: To be reached Class 0 (completely oil-free) residue ≤ 0.01 mg/m & sup3;. Oil will be adsorbed on the wafer surface, affecting chip performance and yield, and even corrosion equipment.
   • Water content: Dew point temperature ≤-40°C (some processes require below -70°C). Excessive dew point will cause moisture condensation, causing equipment rust, photoresist performance degradation and other problems.
   • Particulate matter: Requires compliance ISO 8573-2 Class 1, I .e. particles above 0.1μm ≤ 200 particles/m & sup3;. Particle adhesion can cause short circuit and open circuit of electronic components.
2. SEMI F58-0701
   • the purity of gas and liquid is specified, and the total sulfur content is required to be ≤ 0.1 ppm, and there is no siloxane contamination. Sulfur and siloxane can contaminate semiconductor materials and affect process stability.
3. SEMI C1.3
   • for wafer transfer systems, compressed air is passed through high efficiency filter (HEPA grade) further filtering of small particles.

Detailed explanation of key 2. parameters

1. oil content control
   • adopt oil-free screw compressor or water Lubrication/PTFE Coating Technology avoid oil contamination.
   • Configuration activated carbon filter(degreased vapors) and ultra-precision filter(0.01μm level) to ensure that the residual oil content is extremely low.
2. Water content control
   • use adsorption dryer or freeze dryer reduce the air temperature, heat to close to the original temperature after the precipitation of water, so that the water content reached a very low level.
   • Installation dew point sensor real-time monitoring with traceable data (FDA 21 CFR Part 11).
3. Particulate matter control
   • pipe Adoption electrolytically polished stainless steel tube(Ra≤ 0.4 μm), welded connection reduces leakage.
   • Regularly check the amount of particulate matter to ensure compliance with the ISO 8573-2 Class 1 standard.

3. application scenarios and special requirements

1. wafer Transfer and Robotics
   • oil-free and dust-free compressed air is required to drive the cylinder to avoid particles from scratching the wafer surface.
2. Lens cleaning and reaction chamber isolation
   • control total organic carbon (TOC)≤ 50 ppb to prevent organic pollution.
3. Carrier gas application
   • additional detection of CO₂ and NOx content (usually ≤ 1 ppm) is required to avoid chemical impurities affecting the process.
4. positive pressure ventilation system
   • requires compliance ISO 14644-1 Class 5 Cleanliness prevent dust from entering the clean room.

4. testing and verification requirements

1. third Party Testing
   • A compliance report is issued by an authority (e. g. SGS, TÜV) to ensure that the compressed air quality is up to standard.
2. Periodic verification
   • quarterly detection of oil content, dew point and particulate matter, annual full analysis, continuous monitoring of quality stability.