Introduction

As semiconductor manufacturing transitions toward higher levels of automation and standardization, wafer carriers—the containers that safely transport wafers between process tools—have become increasingly specialized. Two major carrier types dominate modern fabs: the FOUP (Front Opening Unified Pod) and the FOSB (Front Opening Shipping Box).

While both serve to protect wafers during handling and transfer, they differ in design, purpose, and compatibility. To support these diverse carriers, modern Load Ports must be engineered with adaptable interfaces that accommodate 150mm, 200mm, and 300mm wafer sizes.

Understanding FOUP and FOSB

FOUP: Front Opening Unified Pod

The FOUP is the industry-standard wafer carrier for automated 300mm semiconductor fabs. It is a sealed, rigid container that protects wafers from particle contamination and enables automated loading and unloading through a standardized front interface.

Key characteristics include:

● Fully enclosed structure maintaining Class 1 clean conditions inside

● Front door interface that connects directly to the Load Port

● RFID identification for automated material tracking

● SEMI-standard compatibility (E47.1, E62, E63, and others)

FOUPs are optimized for integration with AMHS (Automated Material Handling Systems) and EFEMs (Equipment Front-End Modules), ensuring wafers are transferred automatically without human contact.

FOSB: Front Opening Shipping Box

FOSBs are primarily designed for wafer storage and transport, especially between fabs or during long-distance shipping. Although they resemble FOUPs in shape, they are not designed for continuous in-fab automation.

Key characteristics include:

● Less complex design optimized for protection during shipping

● Simplified locking mechanism without full automation features

● Manual or semi-automatic operation

● Often used in R&D, pilot lines, or wafer logistics

Because of these differences, Load Ports that support FOSBs require customized docking and alignment mechanisms to ensure secure and clean handling.

Load Port Compatibility Across Wafer Sizes

Wafer carriers—and thus Load Ports—are standardized for three main wafer diameters: 150mm, 200mm, and 300mm. Each generation comes with distinct structural and interface requirements.

150mm Load Ports

● Typically used for legacy production tools or research applications.

● Support open cassettes or FOSB-type carriers.

● Often manually operated, though semi-automatic options are available.

● Simpler mechanical interface and lower automation integration.

200mm Load Ports

● Used in mature technology nodes and specialty fabs (MEMS, power devices).

● Can accommodate open cassettes, FOSBs, or semi-sealed carriers.

● May include mapping sensors and ID readers, depending on fab automation level.

● Offer a balance between manual operation and partial automation.

300mm Load Ports

● Fully aligned with FOUP-based automated fabs.

● Designed for complete SEMI-standard compliance (E15, E47.1, E84, E87).

● Include automated door openers, wafer mapping, and RFID modules.

● Seamlessly integrate with EFEMs and overhead AMHS systems for continuous, contamination-free handling.

These Load Ports represent the highest level of automation and are essential for advanced semiconductor production environments.

Designing for Compatibility

To ensure flexibility across carrier types and wafer sizes, Load Port manufacturers incorporate several adaptive design strategies:

● Adjustable Docking Interfaces – Modular platforms allow alignment with different FOUP or FOSB baseplate geometries.

● Interchangeable Door Mechanisms – Customized openers accommodate varying latch and seal designs between FOUPs and FOSBs.

● Smart Sensing and Communication – The Load Port automatically detects the carrier type and adjusts its docking and interlock sequence.

● Wafer Size Recognition – Integrated sensors and configuration files enable the same Load Port frame to support multiple wafer diameters when equipped with the correct adapter kits.

These design innovations allow fabs and OEMs to optimize production flexibility while maintaining SEMI-standard compatibility and high equipment utilization.

Conclusion

As the semiconductor industry continues to operate across multiple wafer sizes and carrier standards, Load Port compatibility with FOUP and FOSB systems is essential for both automation efficiency and process reliability.

A well-designed Load Port bridges the gap between different carrier types—supporting legacy FOSB and open cassette systems while meeting the rigorous requirements of modern FOUP-based automation. This adaptability ensures a smooth transition for fabs evolving from manual handling to fully automated production.

Fortrend offers FOUP- and FOSB-compatible Load Ports for 150mm, 200mm, and 300mm wafer applications. Each system is built for precise alignment, contamination control, and seamless integration with both legacy and modern automation platforms.

With decades of experience in EFEM and Load Port design, Fortrend provides customized solutions that fit your wafer size, carrier type, and fab automation level.