The Importance of Airflow in a Semiconductor Cleanroom

Posted: May 28th, 2024

Semiconductor manufacturing is an incredibly delicate process, and as such, requires significant levels of control for key environmental factors to ensure the successful production of semiconductor products.

One of the environmental factors that needs to be controlled is the airflow in the cleanroom. This blog explores the importance of airflow in a semiconductor cleanroom and its impact on the manufacturing process, as well as the appropriate solutions required to maintain the airflow required for an effective semiconductor cleanroom. A crucial component for this environment being the need for a cleanroom panel system.

 

The Role of Airflow

Airflow within a cleanroom is critical for several reasons:

1- Contaminant Control:

  • Particle Removal: Consistent airflow aids in the removal of particles generated by equipment, processes, and personnel. High-efficiency particulate air (HEPA) filters and ultra-low penetration air (ULPA) filters are generally used to capture these contaminants.
  • Pressure Gradients: Positive pressure airflow prevents unfiltered air from entering the cleanroom. This is a key part of maintaining a contamination-free environment.
  • Unidirectional Flow: Unidirectional (laminar) airflow systems ensure that air moves across surfaces, effectively sweeping away contaminants and stopping them from settling on sensitive equipment or wafers.

2- Temperature and Humidity Control:

  • Thermal Stability: Consistent airflow is an important part of maintaining stable temperatures, which is needed for processes such as photolithography and etching. Temperature fluctuations can increase the chance of defects in semiconductor wafers.
  • Humidity Regulation: Proper airflow also helps to maintain the required humidity levels: too much humidity can cause condensation and corrosion, while too little can result in static electricity buildup, both of which are detrimental to semiconductor manufacturing. In reality, they tend to have very low humidity and design ways to deal with higher ESD build up (for example, anti-static panels.

3- Electrostatic Discharge (ESD) Mitigation

  • Airflow helps dissipate static charges that can accumulate on surfaces and the personnel working in the cleanroom. ESD can cause immediate damage to semiconductor devices or defects that affect performance over time.

Implementing Effective Airflow Systems

There are 3 main elements involved in cultivating an effective airflow in a cleanroom environment.

1- Design and Layout:

  • Air Showers and Air Locks: Typically connecting cleanrooms to non-controlled areas to help reduce contaminants brought in by personnel and materials.
  • Flow Patterns: Designing the space to be conducive for laminar flow will minimise any turbulence, therefore reducing the risk of particle build up.

2- Filtration:

  • HEPA and ULPA Filters: To ensure they continually provide clean, filtered air, HEPA & ULPA filters need regular maintenance and replacement.

3- Monitoring and Control:

  • Continuous Monitoring: Using sensors and control systems to continuously monitor particle counts, airflow velocities, temperature, and humidity ensures that the cleanroom environment remains within specified limits.
  • Adaptive Controls: Advanced systems can adjust airflow rates and pressure differentials in real-time to respond to changes in contamination levels or process requirements.

Conclusion

In semiconductor cleanrooms, airflow is a fundamental aspect of manufacturing high-quality products. Properly designed and maintained airflow systems help control contamination, maintain thermal and humidity stability, and mitigate electrostatic discharge. Considering the importance of regulating semiconductor cleanroom airflow, it’s wise to invest in quality products designed to aid in this task.

Cleanroom panels play a critical role in supporting the levels of controls required in this environment.  At Gilcrest we offer a range of solutions, such as an air return box, raised air wall as well as others to support optimal airflow in your cleanroom.

Contact us today to learn more about our air flow solutions and how they can help ensure the performance of your semiconductor cleanroom, and the quality of your product.

 

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