What is the semiconductor compressed air standard?

In semiconductor manufacturing, the quality standard of compressed air is extremely strict, and it needs to meet the requirements of cleanliness, chemical purity and stability at the same time. The following are the key parameters and the criteria on which they are based:

1. Core standard system

• ISO 8573-1:2010(Compressed air impurity level)
  • oil content: To be reached Class 0(Completely oil-free, residue ≤ 0.01 mg/m & sup3;).
  • Water content: Dew point temperature ≤ -40°C(Part of process requirements -70°C below).
  • Particulate matter: Requires compliance ISO 8573-2 Class 1(Particles above 0.1μm ≤ 200 particles/m & sup3;).
• SEMI standard(International Semiconductor Equipment and Materials Association)

  • SEMI F58-0701: specifies the purity of gas and liquid, the total sulfur content is required to be less than or equal to 0.1 ppm, and there is no siloxane pollution.

  • SEMI C1.3: For wafer transfer systems, compressed air is passed through high efficiency filters (HEPA grade).

2. Detailed explanation of key parameters

3. Application scenarios and special requirements

• 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.
• lithography and etching process
  • compressed air is used for lens cleaning or reaction chamber isolation, and total organic carbon (TOC) is controlled to ≤ 50 ppb.
• Chemical Vapor Deposition (CVD)
  • when compressed air is used as carrier gas, CO₂ and NOx content shall be additionally detected (usually ≤ 1 ppm).
• Clean room environment control

  • when using compressed air, the positive pressure ventilation system shall comply with ISO 14644-1 Class 5 cleanliness.

4. Key points of system design

• oil-free air compressor adopt water lubrication or PTFE coating technology to avoid oil pollution.

• multistage filtration: Configuration of activated carbon filter (oil vapor), ultra-precision filter (0.01μm grade).

• Pipeline treatment: Use electrolytic polished stainless steel pipe (Ra≤ 0.4 μm), welded connection to reduce leakage.

• real-time monitoring: Install dew point sensor, oil vapor detector, data can be traced (in accordance with FDA 21 CFR Part 11).

5. Validation and authentication

• third Party Testing: A compliance report is issued by an authority (e. g. SGS, TÜV).

• Periodic verification quarterly detection of oil content, dew point and particulate matter, annual full analysis.

The semiconductor compressed air standard needs to run through the whole process of equipment selection, system design and operation and maintenance, and its strictness is designed to avoid process pollution and ensure good product rate. As the process node advances (e. g., below 3nm), higher requirements may be placed on nanoscale particles and new chemical contaminants in the future.