What is SECS/GEM?

SECS (SEMI Equipment Communications Standard)/GEM (Generic Equipment Model) is communication interface protocols for communication between semiconductor equipment and a fab host. Request A Demo

SECS (SEMI Equipment Communications Standard)/GEM (Generic Equipment Model) is communication interface protocols for communication between semiconductor equipment and a fab host. Fab host is a software application that is controlling and monitors equipment processing using SECS/GEM protocol. SECS/GEM compliant equipment can communicate with the fab host using either TCP/IP (using SEMI standards E37 and E37.1 – HSMS) or RS-232 (using SEMI standard E4 – SECS-I).


The SECS/GEM standard interface is used to start as well as stop equipment processing, collect measurement data, select recipes for products, and change variables. With SECS/GEM, all this can be performed in a standard way. SECS/GEM protocol has been standardized by the non-profit association SEMI (Semiconductor Equipment and Materials International). Check to learn more about SEMI standards and SECS/GEM protocol.


In simple words, the SECS/GEM standard defines messages, state machines, and scenarios to enable factory host applications to control as well as monitor manufacturing equipment. GEM standard is officially designated as SEMI standard E30 but is frequently referred to as the GEM or SECS/GEM standard. The GEM is beneficial for both device manufacturers and equipment suppliers as it defines a common set of equipment behavior and communication capabilities to provide functionality as well as the flexibility to support manufacturing. Since the GEM standard has only a few semiconductor-specific features, it has been adopted by other manufacturing industries as well, such as PV.

SEMI Standards:


Specification for the Generic Model for Communications and Control of Manufacturing Equipment (GEM)


Specification for SEMI Equipment Communications Standard 2 Message Content (SECS-II)


Specification for High-Speed SECS Message Services (HSMS) Generic Services


Specification for High-Speed SECS Message Services (HSMS) Generic Services

Among the capabilities offered by the SECS/GEM standard is –

  • For a fab host to start and stop processing
  • For a fab host to select, download, and upload recipes from/to the equipment
  • For a fab host to query the equipment for values of various process parameters and equipment configuration
  • For a fab host to set equipment configuration parameter values
  • For equipment to send alarms to the fab host
  • For a fab host to define reports of various variables and associate them with events such as lot start or
    wafer complete
  • For equipment to send various events and associated reports to the fab host

Since SECS/GEM is a communication protocol, it is platform and technology as well as programming language independent. The host side of a connection is executing on a computer system provided by the factory, and the equipment side of a connection is running on a controller computer provided by the equipment manufacturer. This gives both – the fab as well as the equipment manufacturer interoperability, flexibility, and platform independence. Both, the fab and the OEM can develop their software application without having to worry about communication compatibility, as long as both of them are adhering to SECS/GEM standards.

Best Offers for SECS/GEM Software Solutions

eInnoSys offers SECS/GEM software solutions for equipment manufacturers (OEMs) as well as factories (FABs or ATMs). By integrating eInnoSys’ EIGEMEquipment plug-n-play software with equipment controller software of equipment, OEMs can significantly reduce the cost and time it takes to make their equipment SECS/GEM capable. Likewise, EIGEMHost is a SECS/GEM software for FABs and ATMs (Assembly and Test Manufacturing) to communicate with various equipment in the factory. EIGEMSim is a simulator software for SECS/GEM testing. It is software that can be configured as a host or equipment to test SECS/GEM communication of the other.

SECS describes the communication between a host computer and the equipment using a single connection. In the original concept and even today in the most common scenario, the equipment provides a single SECS interface for exclusive use by a single host. The message types defined by SECS are partially asymmetric – some message types are defined only for host use, others are defined only for equipment, but also many of them are defined for the same use by either side.

However, there is a provision in the SECS standards for sharing a connection by specifying the device identification value in each message. The practice of connection sharing is not recommended for new deployments. It is a common practice that a connection is maintained for long periods of time and only interrupted if the equipment or host is rebooted. SECS connections are lightweight and don’t use much network bandwidth. It is possible to run several SECS connections on a typical desktop computer.

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