In today’s semiconductor industry, wafer sorters serve as the critical link between processing tools, inspection stations, and storage systems. As fabs adopt more automation and integrate legacy and modern nodes, different types of wafer sorters are required to handle a wide range of wafer formats and carrier systems. Understanding the differences between Open Cassette Sorters, FOUP Sorters, and Bridge Sorters is key to selecting the right equipment for optimized throughput, cleanliness, and compatibility.

Open Cassette Sorter

Overview

Open Cassette Sorters are typically used for 150mm and 200mm wafers and are common in legacy fabs, pilot lines, and R&D environments. These systems handle top-opening open cassettes, where wafers are exposed to the ambient cleanroom environment.

Key Features

● Compatible with 6" and 8" wafer sizes

● Supports manual loading or integration with semi-automated handlers

● Simple mechanical structure and low maintenance

● Ideal for facilities without full FOUP or SMIF infrastructure

Use Cases

● Mature-node production lines

● Process development and testing labs

● Small-lot or low-throughput applications 

FOUP Sorter

Overview

FOUP (Front Opening Unified Pod) Sorters are designed for 300mm wafers, housed in sealed FOUP carriers. These systems are built for highly automated, ultra-clean environments and support direct communication with factory automation systems.

Key Features

● Full compatibility with SEMI E84, E87, and E88 standards

● Integration with AMHS (Automated Material Handling Systems)

● Supports automatic ID reading, wafer alignment, flipping, and mapping

● Operates in ISO Class 1–10 cleanrooms

Use Cases

● High-volume 300mm fabs

● Fully automated front-end process environments

● Inline metrology or inspection equipment

Bridge Sorter

Overview

Bridge Sorters are hybrid systems designed to connect different wafer sizes or carrier types, often enabling transition from open cassette environments to FOUP-based automation. They “bridge” gaps between legacy and advanced manufacturing lines.

Key Features

● Dual-load capability: supports both open cassettes and FOUPs

● Can transfer wafers between 200mm and 300mm carriers

● Often equipped with OCR/ID reading, notch alignment, and flip modules

● Helps maintain fab flexibility during node migration or integration phases

Use Cases

● Facilities upgrading from 200mm to 300mm

● Mixed-node fabs supporting both mature and advanced process flows

● Equipment manufacturers requiring tool-to-tool transfer between formats

Choosing the Right Wafer Sorter for Your Fab

● Selecting the appropriate wafer sorter depends on a combination of factors:

● Wafer size: 150mm, 200mm, or 300mm

● Carrier type: Open cassette, FOUP, SMIF

● Level of automation: Manual, semi-auto, or full AMHS integration

● Process requirements: Yield sensitivity, cleanliness, traceability

● Legacy vs. advanced node support

Wafer sorters are not one-size-fits-all. The right configuration ensures smoother process flows, better yield management, and lower risk of contamination or misprocessing.

Conclusion

From open cassette systems supporting legacy wafers to fully automated FOUP sorters and flexible bridge solutions, wafer sorters are essential for material handling across the semiconductor value chain. As fabs evolve toward higher levels of automation and node diversity, the demand for versatile, intelligent sorter systems will only continue to grow.

Fortrend offers a full range of wafer sorter solutions tailored for 150mm, 200mm, and 300mm environments. Whether you’re managing a legacy fab or scaling into advanced automation, our systems help optimize wafer flow and production efficiency.

Contact our team to learn more about the right solution for your operation.