​​What is FOUP in Chip Manufacturing?​​

In semiconductor manufacturing, a ​​Front Opening Unified Pod (FOUP)​​ is a critical container used to protect, transport, and store wafers. Designed to hold ​​25 pieces of 300mm wafers​​, its primary components include a front-opening chamber and a dedicated door frame. As the core carrier in automated transport systems for 12-inch wafer fabs, FOUPs remain closed during transit and only open when positioned at a tool’s loading port for wafer transfer.

FOUPs are engineered to meet stringent microenvironment requirements. Their rear features wafer slots compatible with robotic arms, while the door aligns precisely with gripper mechanisms. Wafer handling robots operate in ​​Class 1 cleanrooms​​ (≤10 particles ≥0.1 μm/m³), ensuring contamination-free transport. Modern fabs utilize ceiling-mounted rail systems for FOUP movement, though older facilities may employ ground-based automated guided vehicles (AGVs).

Beyond transport, FOUPs serve as storage solutions. Due to lengthy manufacturing cycles (spanning months) and high monthly output, tens of thousands of wafers may be in transit or temporary storage at any time. FOUPs undergo periodic nitrogen purging to prevent pollutant exposure, maintaining ultra-high cleanliness during storage.

Core Functions & Importance​​

FOUPs protect wafers from mechanical shock and contamination during transit, directly impacting yield. Advanced FOUPs employ ​​gas purging​​ and ​​Localized Atmosphere Control (LAC)​​ to mitigate humidity and volatile organic compounds (VOCs). Their sealed systems restrict external elements—oxygen, moisture, and contaminants—to levels <3 particles/hour inside.
 

A full FOUP weighs ​​9 kg​​, necessitating automated material handling systems (AMHS) for transport. FOUPs integrate coupling plates, pins, and holes for AMHS compatibility, along with ​​RFID tags​​ for real-time tracking and classification. This automation minimizes human error and enhances safety/accuracy.​

Structural & Functional Classification​​

​1. Dimensions​​: 420 mm (W) × 335 mm (D) × 335 mm (H).

2. ​Key Components​​:

• ​​Top OHT (Overhead Handling Transport)​​: Interface for crane systems.
• ​Front Door​​: Wafer loading/unloading port.
• ​​Side Handle​​: Color-coded to denote contamination zones (e.g., red for high-risk areas).
• ​RFID Tag​​: Unique identifier for tool/amhs recognition.
• ​Alignment Holes​​: Four positioning points for tool compatibility.

​​3.Usage Categories​​:

• ​​PRD (Production)​​: For final product wafers.
• ENG (Engineering)​​: For R&D/experimental wafers.
• MON (Monitoring)​​: For process monitoring (CMP, lithography, etc.).
• Note: PRD FOUPs can be used for ENG/MON, ENG can use for MON，but reverse usage risks contamination.

4. ​​Contamination Grading​​:

•​FE FOUP​​: Front-end (metal-free processes).

•​BE FOUP​​: Back-end (metal-containing processes).

•​Specialized Types​​: NI (nickel), CU (copper), CO (cobalt) for specific metallization steps.

•​Note: Front-end FOUPs are compatible with back-end processes, but not vice versa.

​​Conclusion​​

FOUPs are indispensable in modern fabs, combining advanced automation, contamination control, and durability to safeguard wafers through complex manufacturing cycles. Their design directly supports yield optimization and high-volume production scalability.

As a leading domestic manufacturer of semiconductor core carriers, ZMSH are committed to delivering ​​end-to-end solutions​​ centered on lifecycle services, including customized design, rapid delivery, and post-sales technical support. Leveraging an ​​AI-driven supply chain network​​ and deep collaboration with global tier-1 fabs, we ensure 48-hour global response and 72-hour emergency replacement services to maintain production continuity. Moving forward, we will expand our ​​localized service network​​ to provide more efficient and secure wafer transportation solutions for the global semiconductor industry through technological iteration and ecosystem synergy.