In semiconductor manufacturing, seamless communication between equipment is essential for efficient automation. A load port is more than a mechanical interface—it’s a smart communication hub linking the Automated Material Handling System (AMHS), Equipment Front End Module (EFEM), and host control system. Two key communication standards, SECS/GEM and SEMI E84, form the foundation of this connectivity, enabling precise coordination in wafer transport, carrier management, and equipment control.

Understanding SECS/GEM Communication

SECS/GEM (SEMI Equipment Communication Standard/Generic Equipment Model) is a software-level communication protocol defined by SEMI standards E5, E30, and related specifications. It provides a standardized method for data exchange between semiconductor equipment (such as a load port) and the factory host computer.

Through SECS/GEM, the load port can:

● Report status changes, such as carrier arrival, docking, or door open/close events.

● Send and receive commands, allowing the host system to control load port operations or query system parameters.

● Monitor alarms and events, improving process visibility and predictive maintenance.

● Enable data collection, supporting yield analysis and manufacturing optimization.

In essence, SECS/GEM provides the “language” that allows the host to monitor, command, and log every load port activity within a highly automated fab.

The Role of E84 in Material Transport

While SECS/GEM handles software communication, SEMI E84 defines the hardware-level handshake between the load port and the AMHS. This protocol governs the precise sequence of electrical signals exchanged during carrier transfer—covering approach, docking, clamping, and undocking actions.

The E84 interface uses photoelectric sensors and digital I/O signals to coordinate the timing between the load port and the OHT (Overhead Hoist Transport) or OHS (Overhead Shuttle). These signals ensure safe, reliable, and fully automated FOUP delivery without operator intervention.

In practical terms, SECS/GEM and E84 work hand-in-hand:

● E84 manages physical carrier movement.

● SECS/GEM manages data, status, and control logic.

Together, they synchronize every step of wafer loading and unloading within the automation network.

Communication with EFEM and Host Systems

Within an integrated EFEM (Equipment Front End Module), the load port serves as the entry point for wafer carriers. Once a FOUP is docked and verified through E84 signals, the EFEM’s control system coordinates with the host computer via SECS/GEM.

The host system can then:

● Identify the carrier through RFID or ID readers.

● Initiate wafer mapping and alignment.

● Trigger robot transfers to the processing module.

This multi-level communication structure ensures that every wafer is tracked, verified, and transferred according to the factory’s automation logic—supporting both traceability and production efficiency.

Why Communication Standards Matter

Without SECS/GEM and E84, fabs would face complex proprietary integrations and reduced automation reliability. By following these SEMI standards, load ports can operate seamlessly within diverse toolsets, ensuring interoperability between different vendors and equipment generations.

Fortrend designs and manufactures SEMI-compliant load ports equipped with SECS/GEM and E84 communication interfaces. Our systems ensure full compatibility with modern AMHS and EFEM architectures, enabling reliable, high-speed wafer handling across all automation levels.

Contact Fortrend today to learn more about our advanced load port and automation solutions for semiconductor manufacturing.