With the expansion of the computing, telecommunications, and automotive and military electronics markets, the microelectronics and semiconductor industry has experienced substantial growth. These industries rely on complex processes and a wide variety of chemicals. Given the often microscopic scale of the components produced, even minimal contamination can have severe consequences. Advanced microelectronics manufacturing methods therefore require the use of extremely clean fluids (water, chemicals, air, gases). And this requirement continues to intensify with ongoing miniaturization. Controlling and preventing micro-contamination is thus a constant concern in semiconductor device manufacturing.
Multiple sources of contamination
Ces contaminations ont des origines diverses et des effets multiples sur la production. Les contaminants organiques peuvent par exemple endommager les substrats, avec une répercussion négative sur les rendements de production. La contamination moléculaire aéroportée (AMC) est elle aussi désormais un enjeu majeur pour tous les sites de prodThese contaminants originate from multiple sources and have various impacts on production. Organic contaminants, for example, can damage substrates, negatively affecting production yields. Airborne molecular contamination (AMC) has also become a major concern for all advanced microelectronics manufacturing sites. The presence of submicronic insolubles in chemicals must likewise be avoided, as these residues can scratch semiconductor wafers.
Submicron particles present in inert and specialty gases used for dry-coating operations (atomic layer deposition, physical vapor deposition), diffusion, oxidation, and metal deposition processes can settle on the substrate and create critical defects. In plasma etching, highly reactive and corrosive ultra-high purity (UHP) gases are used to etch or remove silicon, polymers, or certain metals, and therefore require pre-filtration.
Overall, all these contaminants can affect production yields and the quality of finished products through:
• mechanical effects: scratching, airflow obstruction, interference with moving or optical components, surface deformation
• chemical effects: corrosion of electrical components
• electrical effects: impedance variations and modifications of electronic circuit properties
Filtration of submicron contaminants is therefore a key factor in reducing defects that compromise quality throughout microelectronics manufacturing processes.
Filters must therefore be installed in production facilities manufacturing:
• silicon wafers
• transistors
• chips for computers and tablets
• chips for mobile phones
• chips for IoT sensors and control devices
• microelectromechanical systems (MEMS)
• hard drives
The porous media used in these industries are avail…ibles avec une vaste gamme de tailles de pores et dans différents matériaux : Teflon™, PES , fibres ou poudre de métal fritté en acier inoxydable 316, fibres et poudre de nickel fritté, poudre d’Hastelloy® C22 fritté.
Producing ultrapure water
The microelectronics industry requires very large quantities of ultrapure water (UPW) as part of its manufacturing processes. Cleaning, rinsing, and etching semiconductor wafers and substrates consume thousands of cubic meters of UPW per day in most facilities.
To meet the purity levels required for ultrapure water in the microelectronics sector, raw water undergoes a multi-step treatment sequence, including filtration. The standards and specifications used to assess water purity in semiconductor manufacturing are primarily based on particle measurement and Total Organic Carbon (TOC) contamination.
Ultrapure water used in the semiconductor industry is similar to pharmaceutical-grade water.
Traditionally, most ultrapure water systems for microelectronics were equipped with pleated membrane filters with a filtration rating between 0.04 and 0.02 µm. However, hollow-fiber technology now delivers unmatched performance in this area. Experimental tests have shown that polysulfone (PS) hollow-fiber filters (0.05 µm) installed downstream of reverse osmosis units are as effective—or even more effective—than pleated membrane filters of 0.02 and 0.03 µm made of polyethersulfone (PES) or polysulfone (PS).
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Hollow-fiber filters also have, unlike other filters, the ability to reduce Total Organic Carbon (TOC) by retaining endotoxins present in the water.
Achieving high-purity chemicals
Chemicals are used in numerous processes: etching, texturing, chemical mechanical polishing (CMP), thin-film deposition. They must be of the highest purity. To achieve this, qualified PTFE media filters, hollow fibers, and high-purity PFA external components (cages, cores, end caps, etc.) are used. The choice of the most suitable industrial filter depends on the required chemical and thermal compatibility.
Preventing airborne contamination in cleanrooms
Airborne molecular contamination (AMC) produces a wide range of effects and significantly impacts productivity. Corrosion of chips, hard drives, or wafers by acidic compounds, condensable organic deposits on sensitive surfaces, or exposure to low levels of ammonia can all disrupt production processes. Just a few particles or gas molecules, such as ozone, are enough to cause yield losses.
In some facilities, wafers may spend an entire month inside the plant and undergo hundreds of operations before being integrated into a final product. Any contamination, even minimal, at any point in this processing chain can have serious consequences for overall production yield. For cleanroom air filtration, two main filter types are used: HEPA filters (High Efficiency Particulate Air) and ULPA filters (Ultra Low Penetration Air), depending on the cleanliness class required.
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