Semiconductor chips are used in every computerized device — from household objects like your cell phone or coffee maker to complex machines like vehicles, defense technology, or spacecraft. They’re produced using highly sensitive materials to create delicate layers that must be worked on with care. That’s why tasks like semiconductor chip manufacturing, testing, and packaging must be carried out in a controlled cleanroom environment.
Below, we explore more about semiconductor cleanrooms, including their common applications, classifications, and design features.
What are Semiconductor Cleanrooms?
Before we dive into the many specialized features of semiconductor cleanrooms, let’s back up and get a better understanding of what semiconductors are and why they must be handled within a cleanroom.
What Are Semiconductors?
Semiconductors are made using a glassy, solid material of pure silicon, which is shaped in a molten state and then cut into thin wafers. Semiconductors are prized for their special conductive behavior — which behaves both like a metal and an insulator — and are a vital ingredient for manufacturing computer chips and circuitry. A wafer is a substrate that’s used for the base in an integrated circuit, or chip.
Semiconductor chips are fragile materials. Even the slightest inconsistency can compromise their safety and effectiveness — and in turn, compromise the safety and effectiveness of the machines and equipment powered by those chips. That’s why semiconductor cleanrooms are important and why they must comply with strict standards to ensure total control over the chip manufacturing environment.
Boost to the Semiconductor Industry
In August 2022, the United States government passed the CHIPS and Science Act. This act was created with the intention to boost semiconductor chip manufacturing and bring more of it back to the U.S. rather than overseas. It authorized nearly $52 billion in government subsidies for U.S. semiconductor manufacturing and research, as well as an estimated $24 billion in investment tax credits for semiconductor chip manufacturers.
Needless to say, this act has impacted the nation’s semiconductor industry tenfold. Plants that once had to stall their semiconductor projects due to lack of funding and resources can now resume. Other semiconductor chip manufacturing companies are likely to expand their operations. In order to do that, they’ll need more cleanrooms.
Sound like you? Contact Angstrom Technology to get started on your semiconductor cleanroom project today.
Semiconductor Cleanroom Applications
Semiconductors are used in many industries and applications. Whenever maintaining quality and purity in semiconductor chip manufacturing is crucial (which is all the time), a cleanroom is required. Some of the most common industries and applications that require semiconductor cleanrooms include:
- Computer and cell phone manufacturing
- Automotive manufacturing
- Aerospace and defense manufacturing
- Robotic and automated equipment manufacturing
- Household appliance manufacturing
- Biotechnology manufacturing
Semiconductor Cleanroom Classifications
Semiconductor cleanrooms often run 24 hours per day due to our technologically inclined society’s demand for valuable circuitry components. Some of the most stringent cleanroom classifications must be maintained consistently throughout the chip manufacturing process.
In most cases, semiconductor cleanrooms must comply with ISO 14644-1 Class 4-6 requirements. This stipulates a maximum allowed particle count between 352-35,200 particles 0.5μm or smaller. They must also meet the requirements of ISO 14644-2, which imposes a quality control system in order to maintain these standards. However, not all processes require such stringent control. The packaging, assembly, and testing of manufactured wafers could be performed in ISO class 7 or ISO class 8 cleanrooms.
Depending on their unique application, semiconductor cleanrooms will also likely have to meet some industry-specific requirements, for example, ASTM standards for automotive applications and NASA standards for aerospace applications. These are usually complied with in addition to ISO standards to ensure that semiconductor cleanrooms are always controlled and that the chips that come out of them are of consistent quality.
Any drop below these stringent standards could lead to defects.
Semiconductor Cleanroom Design
Semiconductor cleanrooms require a robust cleanroom design that helps them reach and maintain strict cleanliness standards while also allowing for easy movement and workflow. Here are a few especially important semiconductor cleanroom design aspects to consider.
Operators & Operator Processes
Just like with any other type of cleanroom, the biggest threat to cleanliness and control in semiconductor cleanrooms is the people working within them. That’s why semiconductor cleanroom operators must be specially trained and outfitted to prevent contamination.
But this semiconductor-operator relationship goes both ways. Semiconductors and the processes that are needed to manufacture circuitry from them can be harmful to human health. Therefore, it’s important to design semiconductor cleanrooms in way that allows operators to complete tasks safely. Some semiconductor cleanrooms even have robotic equipment or special safety protocols in place to protect workers from radioactive processes, toxic chemical exposure, lasers, and magnetic fields.
Air Quality & Filtration
As mentioned above, semiconductor cleanrooms must have a high level of air quality — some of the cleanest air required for any cleanroom application. This starts with powerful cleanroom HVAC and filtration systems, like HEPA or ULPA filters, which are used to process the air to remove particles up to allowed limits.
Machines within the cleanroom may also have their own exhaust system that removes unclear air and particulate matter.
Other Environmental Threats
Aside from airborne particle filtering, semiconductor cleanrooms must also be protected against other environmental threats. Control is especially important over factors like:
- Static – Electro-static discharge damages the conductive properties of semiconductors. Static dissipative materials for flooring, wall panels, furniture, and more must be used.
- Humidity – Uncontrolled humidity in semiconductor cleanrooms can result in inconsistent bake-out times, surface swelling and corrosion, and evaporation of solvents. A consistent relative humidity between 35-65% is necessary.
- Out-gassing – Semiconductor cleanroom equipment can produce outgassing and introduce airborne contaminants into the space. This must be controlled with proper equipment cleaning and maintenance, as well as consistent air filtration.
Do You Have a Semiconductor Cleanroom Project in Mind? Let’s Talk!
If your facility needs a new semiconductor cleanroom, Angstrom Technology can design, build, and install one that meets your specifications. Using proven design strategies and static dissipative materials, you can trust that your work and employees will always be protected.
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