Special Requirements for Semiconductor Filter Cartridges
As semiconductor processes advance toward nanometer-scale nodes, filter cartridge requirements are evolving toward higher precision, resistance to extreme conditions, and customization. Depending on specific process steps, the selection criteria for filter cartridges may vary.
Wet Cleaning Process
Wet processing, a critical step in semiconductor manufacturing, uses chemicals (acids, alkalis, solvents, etc.) and liquid media such as ultra-pure water to etch and clean the wafer surface. A typical wafer cleaning process is shown below.
Typical Water Cleaning Process
This process stage typically involves highly corrosive media, including acids (SPM, DHF, SC-2), alkaline solutions (SC-1), and oxidizing agents (H₂O₂), and demands the removal of nanoscale particles and metallic ions.
Membrane Solutions offers high-performance filtration solutions for semiconductor wet processes. Our filter cartridges are specifically engineered for liquids such as SC-1, SC-2, 49% HF, HNO₃, EKC, and NMP. A wide range of application-specific cartridges have been developed to effectively remove particles from high-purity chemicals, helping to safeguard and improve wafer yield.
Typical Cleaning Tank Process (Take SC1 as an example)
Semiconductor Wet Process Applications
Product Recommendation
Membrane Solutions has independently developed the ExafPure WF series all-fluoropolymer filter cartridges, which offer excellent high-temperature and corrosion resistance, along with low extractables, meeting the requirements of most wet process applications.
This series utilizes high-flow-rate PTFE membranes and is specifically designed for liquid filtration in semiconductor wet applications, including SC-1, SC-2, 49% HF, HNO₃, EKC, and NMP.
Product Features & Advantages:
🔹 Excellent flow rates and extended service life
🔹 Superior chemical and temperature resistance
🔹 All-fluoropolymer construction with ultra-low extractables
🔹 Convenient pre-wetting options
🔹 100% filter cartridge integrity testing
Chemical Mechanical Planarization (CMP)
CMP slurries consist of abrasive particles, buffers, and polishing agents. If particulate contaminants are introduced into the slurry, they may cause wafer surface damage or even circuit shorting.
In this process step, filter cartridges are typically made of depth-structured polypropylene (PP) or high-flow, high dirt-holding capacity polyethersulfone (PES). They are required to effectively remove agglomerates and colloids, filter out large particles, while retaining the nanoscale abrasive particles in the slurry, thereby improving slurry purity.
CMP Slurry Conveying System:
Semiconductor Chemical Mechanical Planarization (CMP) Applications
Membrane Solutions offers filter cartridges specifically designed for chemical mechanical polishing (CMP) filtration. These cartridges effectively remove agglomerated particles and colloids from various CMP slurries while retaining the desired abrasive particles and maintaining the slurry's particle size distribution. Recommended filter options include:
Product Recommendation
Membrane Solutions' PoliCap-Plus series is a capsule filter specifically designed for CMP filtration applications. It is suitable for filtering CMP slurries containing colloidal SiO₂, CeO₂, and ultrafine Al₂O₃ abrasives, effectively reducing process defect rates. Structurally, its convenient disposable design enables quick installation while minimizing slurry exposure and waste
Product Features & Advantages:
🔹 100% polypropylene construction for cost efficiency
🔹 Disposable design for easy replacement and reduced slurry exposure
🔹 Low hold-up volume to minimize slurry waste and prevent sedimentation
🔹 Multiple filter media and adaptor options available
🔹 Low pressure drop with excellent particle removal efficiency
🔹 High dirt-holding capacity and extended service life
Photolithography Process
In photolithography, the process media requiring filtration include photoresists, developers, and strippers. These applications demand extremely high removal rating and excellent chemical compatibility (resistance to strong polar organic solvents such as propylene glycol monomethyl ether acetate (PGMEA) and dimethyl sulfoxide (DMSO)). Filter cartridges used in this process are typically made of high-cleanliness, high-performance materials such as PTFE, UPE, or Nylon.
Semiconductor Photolithography Applications
Product Recommendation
Membrane Solutions' Photo-Unix series UPE membrane filter cartridges offer a removal rating range from 2nm to 0.2μm. They utilize ultra-low extractables HDPE (high-density polyethylene) plastic components, delivering high cleanliness, low particle shedding, excellent contaminant removal performance, and strong chemical resistance, making them suitable for various SEMI photolithography applications.
Product Features & Advantages:
🔹 High filtration efficiency
🔹 Excellent chemical resistance
🔹 Superior inherent cleanliness
🔹 Low metal and organic extractables
🔹 100% filter integrity testing
In semiconductor processes, filters must not only meet the above requirements but also possess excellent initial cleanliness. Initial cleanliness plays a critical role in enabling rapid filter startup and reducing wafer defect rates. Once particles or metal contaminants are released from the filter, they can ultimately impact downstream chip yield.
To obtain filters suitable for high-purity applications in semiconductor manufacturing, the filters need to be effectively cleaned to further reduce trace extractables. Proper cleaning processes are essential to ensuring initial cleanliness. Filters that are not adequately cleaned may fail to perform effectively and can even become contamination sources, releasing particles, organics, or metal ions that affect product yield and lead to significant economic losses. Therefore, an effective filter cleaning process is crucial for semiconductor production.
Membrane Solutions Filter Cleaning Process
Pre-cleaning Stage
Before formal production, raw materials are cleaned using volatile polar solvents and ultrapure water to remove soluble contaminants. After filter formation, additional ultrapure water cleaning is applied to remove loosely attached surface particles and residual soluble contaminants introduced during manufacturing, preventing cross-contamination in subsequent chemical cleaning steps.
Deep Decontamination Stage
Different chemical cleaning agents are used depending on the type of contaminants. For organic contaminants, strong oxidizing agents break them down into small molecules such as CO₂ and H₂O for effective removal. For metallic contaminants, acidic cleaning agents combined with specific additives are typically used to achieve targeted chelation and removal.
Schematic Diagram of Cleaning and Contaminant Removal Using Chemical Cleaning Agents and Ultrapure Water
Membrane Solutions Filter Cleanliness Testing Methods
For semiconductor filters, key cleanliness indicators include resistivity, TOC (Total Organic Carbon), metal ion extractables, anion extractables, and particle shedding. Membrane Solutions operates a CNAS-accredited validation center, where all high-cleanliness filter products undergo rigorous testing, including ICP-MS, IC-MS, and DLS, to ensure that the filter cleanliness meets customer requirements.
As a professional filtration solution provider, Membrane Solutions is committed to delivering high-quality products and services. Leveraging advanced cleaning processes, Membrane Solutions provides customized high-cleanliness filtration solutions to meet the cleanliness control requirements of advanced customers, reduce the risk of secondary contamination, and help customers achieve cost reduction and efficiency improvement for mutually beneficial cooperation. For more information about Membrane Solutions' microelectronics filtration products and application cases, please feel free to contact us.