SECS (SEMI Equipment Communications Standard)/GEM (Generic Equipment Model) is correspondence interface conventions for correspondence between semiconductor gear and a fab host. Fab host is a product application that is controlling and screens hardware handling utilizing SECS/GEM convention. SECS/GEM consistent gear can speak with the fab host utilizing either TCP/IP (utilizing SEMI guidelines E37 and E37.1 – HSMS) or RS-232 (utilizing SEMI standard E4 – SECS-I). The SECS/GEM standard interface is utilized to begin just as stop hardware handling, gather estimation information, select plans for items, and change factors. With SECS/GEM, this can be acted in a standard way. SECS/GEM convention has been normalized by the non-benefit affiliation SEMI (Semiconductor Equipment and Materials International). Actually, take a look at www.SEMI.org to find out about SEMI principles and SECS/GEM convention.
To comprehend the SECS/GEM guidelines you should buy the accompanying 3 fundamental principles from SEMI:
SEMI E30 GEM Standard
Specification for the Generic Model for Communications and Control of Manufacturing Equipment (GEM)
This specification defines a standard implementation framework of SECS-II messages for basic semiconductor manufacturing equipment. By defining a common set of equipment behavior and communications capabilities around data collection, alarm management, remote control, configuration, and control, this Standard allows equipment suppliers to develop a single SECS-II interface that provides a solid foundation for host automation. It also allows device manufacturers to implement unique automation solutions within a common industry framework. This standardization reduces the cost of software development for both equipment suppliers and device manufacturers, which would in turn allow device manufacturers to automate semiconductor factories more quickly and effectively.
SEMI E5 SECS-II
SEMI E5 - Specification for SEMI Equipment Communications Standard 2 Message Content (SECS-II)
This Standard, otherwise known as the Specification for SECS-II messages, works with the Protocol Layer to define how messages are communicated between equipment and host. The functions defined in this Standard support the most typical activities required for IC manufacturing. Together with other SECS/GEM Standards, SEMI E5 helps define a software interface for monitoring and controlling manufacturing equipment.
SEMI E37 HSMS
High-Speed SECS Message Services (HSMS) provide a means for independent manufacturers to produce implementations that can be connected and interoperate without requiring specific knowledge of one another.
HSMS is intended as an alternative to SEMI E4 (SECS-I) for applications where higher speed communication is needed or when a simple point-to-point topology is insufficient. SEMI E4 (SECS-I) can still be used in applications where these and other attributes of HSMS are not required.
SEMI E30 GEM STANDARD
SEMI E30 - Specification for the Generic Model for Communications and Control of Manufacturing Equipment (GEM)
This specification defines a standard implementation framework of SECS-II messages for basic semiconductor manufacturing equipment. By defining a common set of equipment behavior and communications capabilities around data collection, alarm management, remote control, configuration, and control, this Standard allows equipment suppliers to develop a single SECS-II interface that provides a solid foundation for host automation. It also allows device manufacturers to implement unique automation solutions within a common industry framework. This standardization reduces the cost of software development for both equipment suppliers and device manufacturers, which would in turn allow device manufacturers to automate semiconductor factories more quickly and effectively.
Communication
The COMMUNICATION state model defines the behavior of the equipment in relation to the existence or absence of a communication link with the host. It also defines how communication is established or re-established with S1F13/S1F14 when communication is broken
Control
The CONTROL state model defines the level of cooperation between the host and equipment. The CONTROL model provides the host with three basic levels of host control which determine the host's ability to control the equipment:
OFFLINE (Lowest Level): Operation of the equipment is performed manually by the operator at the operator console. Equipment will respond with an SxF0 to any primary message from the host other than S1F13 or S1F17.
ONLINE/LOCAL (Middle Level): In this state, the host is only allowed to perform "read-only" operations like data collection. The host shall be prohibited from modifying any equipment constants that affect processes, remote commands that cause physical movement or which initiate processing.
ONLINE/REMOTE (Highest Level): In this state, the host may operate the equipment to the full extent available through the communications interface ("read-write" operations).
Processing
The PROCESSING state model is highly dependent on the equipment process, technology, and style. However, there are expected to be common aspects to these models.
Remote Command
The host can send commands to instruct the equipment to perform an automatic operation. E.g.: START, STOP, PAUSE, etc. This is similar to the manual operation performed by the operator on the console.
Variables
The GEM standard defines three types of variables that are accessible by the Host:
Status Variable: This is a "read-only" global variable defined in the equipment. Whenever there is processing the equipment will update the respective status variable to reflect the latest data. E.g.: incremental of some counter, current/previous state, etc.
Equipment Constant: This is a "read-write" global variable defined in the equipment. The host can set or modify the equipment constant variable which may affect the setting that in turn change the way equipment's behaviors.
Data Variable: This is a "local" variable which only exists in collection events.
Data Collection
SECS/GEM a couple of avenues for Host to collect data or information from the equipment:
A set of status variable values can be requested at any time using the S1F3 command.
A set of equipment constant values can be requested at any time using S2F13
The host can define a report containing a status variable, equipment constants, and data variable then attaches it to a collection event. When equipment raises the event (using the S6F11 command), the report containing those variables' values will be sent together.
The host can define traces which will do a sampling of status variable data at a periodic basis.
Another way is to leverage alarm notifications to collect more data with collection events. By standard, whenever an occurrence or clearance of an alarm, an event (collection event) must be sent to the Host.
Alarm Notification
This feature allows the Equipment to notify the Host of every occurrence or clearance of an alarm/error on the equipment. Alarm refers to that occurrence that is abnormal, undesirable and endangers people, equipment, or physical material being processed.
Below are some of the characteristics of Alarm Management defined by GEM:
Each alarm has two associated state models. ALARM SET (occurrence) and ALARM CLEAR (clearance)
Each AlarmSet and AlarmClear has an associated Collection Event. This is to address the host's potential need for more extensive and flexible data reporting.
A host can request which Alarms to be enabled/disabled and Equipment will only notify the Host for the enabled Alarms.
