28 Jun Introduction to Semiconductor Cleanrooms
The electronics that power our smartphones, computers, and even our cars are often made in spaces cleaner than a hospital operating room. The smaller the components, the more sensitive they are to damage by tinier particles. And according to Moore’s Law, the number of transistors on an integrated circuit will double every two years, which means they will be sensitive to smaller and smaller particles. As you might’ve guessed, this makes cleanrooms more important than ever. The semiconductor industry relies heavily on them to produce the microchips and integrated circuits that power many modern technologies. In this article, we’ll explore what semiconductor cleanrooms are, their classifications, design features, and more.
What are Semiconductor Cleanrooms?
Semiconductor cleanrooms are controlled environments where airborne particles and several conditions, such as temperature, humidity, and static electricity, are tightly regulated. Such spaces are designed to prevent contamination of semiconductors during many stages of manufacturing, including photolithography, wafer fabrication, and even packaging and assembly. Semiconductor devices are so sensitive that even a few specks of dust can cause serious damage to parts during production.
What are the Classifications of Semiconductor Cleanrooms?
Cleanrooms, within the ISO 14644-1 framework, are classified based on the number of particles per cubic meter of air. The standard defines cleanroom classes from ISO Class 1 to ISO Class 9, with ISO Class 1 being the strictest, allowing the fewest particles, and ISO Class 9 permitting the most.
For most semiconductor processes, cleanrooms need to comply with ISO Class 4-6; however, they may at some times be more strict, depending on the application. This includes processes such as photolithography and wafer fabrication.
Packaging and assembly, on the other hand, are still required to be clean, but much less so, which is why such operations are often housed in ISO Class 7 or ISO Class 8 cleanrooms.
What are the Design Features of Semiconductor Cleanrooms?
Several design aspects of semiconductor cleanrooms are important for successful operations. Here are some of the most significant:
- Air Filtration: Semiconductors use high-efficiency particulate air (HEPA) filters and ultra-low penetration air (ULPA) filters to effectively remove tiny particles from the air. These filters can capture particles as small as 0.3 and 0.12 micrometers, respectively.
- Humidity Control: Controlling humidity levels is another important variable in semiconductor cleanrooms, especially because of its relationship to static electricity. By keeping humidity levels above 30%, these spaces reduce the risk of electro-static discharge, which can damage semiconductors.
- Temperature Control: Keeping a stable temperature is also necessary to prevent damage to semiconductor materials.
- Airflow: Unidirectional airflow, also known as laminar airflow, is another important design feature often found in semiconductor cleanrooms. It’s just what it sounds like: airflow that moves in one direction, typically downward or horizontally, to sweep away contaminants.
- Monitoring Systems: Monitoring is another central aspect in protecting semiconductor processes. Particle counters and environmental monitoring systems track air quality and detect contamination. They provide real-time data, so any deviation in conditions can quickly be addressed.
The Bottom Line
When even a tiny particle can ruin or damage electrical components, cleanrooms become indispensable in the manufacturing process. The recent surge in semiconductor demand has made cleanrooms essential for product reliability. As AI advances, the semiconductor industry will continue to rely on cleanrooms. And as parts shrink, cleanroom technology will need to innovate to meet the growing need for both precision and cleanliness.
Need to build cleanrooms that comply with the strict standards of semiconductor manufacturing? Get a free quote from Allied Cleanrooms today!