Standards can be defined as any voluntary technical agreements between customers and suppliers created with the objective of improving product quality and reliability at an affordable price and steady supply. Standards make sure that interoperability & compatibility of goods and services are maintained.
SEMI standards are written in the form of guidelines, specifications, practices, test methods, terminology, etc. The documents which are published in the 16 volume set of SEMI International Standards. SEMI standards cover each and every aspect of semiconductor manufacturing and photovoltaic: Equipment Automation (Hardware and Software),3D-IC, High Brightness-LED, Facilities, Gases, Microlithography, MEMS/NEMS, Materials, Process Chemicals, Packaging, Photovoltaic, Traceability, Silicon Material & Process Control, and other related issues. Additionally, standards are published for Flat Panel Displays.
GEM defines a standard for implementing all semiconductor manufacturing
Equipment of SECS-II standard.
This standard SEMI E30 defines a common set of communication capabilities and equipment behavior that will provide the flexibility & functionality to support the manufacturing of automation programs for semiconductor device manufacturers. Any additional SECS-II features which are not included in GEM can be included by Equipment Suppliers, the only requirement is this feature should not conflict with GEM standards.
Any such additional features which may be included could be SECS-II messages, codes, variable data items (data values, status values or equipment constants)alarms, collection events, remote command, processing states, or other functionality which is unique to a class (etchers, steppers, etc.) or specific instance of equipment.
The main aim of GEM is to provide economic benefits for both equipment suppliers and device manufacturers. Equipment suppliers benefit from the feature to develop and market a single SECS-II interface that satisfies most customers. Device manufacturers benefit from the increased standardization and functionality of the SECS-II interface across all manufacturing equipment. This standardization reduces the cost of software development for both equipment suppliers and device manufacturers. By reducing costs and increasing functionality, device manufacturers can automate semiconductor factories more quickly and effectively. The flexibility provided by the GEM Standard also enables device manufacturers to implement unique automation solutions within a common industry framework.
The GEM Standard shows the following for Semiconductor Manufacturing Industry:
• The behavioral model to be exhibited by semiconductor manufacturing equipment in a SECS-II communication environment.
• Detailed information on the control functions required in a Semiconductor Manufacturing.
• Definition of the basic SECS-II communication capabilities of semiconductor manufacturing equipment.
• A single consistent way of achieving an action when SECS-II provides multiple ways for the same methods.
• It also shows the Standard message dialogues required to achieve useful communications capabilities.
GEM Standard contains two types of requirements. One is the Fundamental GEM requirements and the other is the requirements of additional GEM capabilities.
The foundation of GEM standards is laid by the fundamental GEM requirements. The additional GEM capabilities offer the functionality required for a few types of factory automation or functionality applicable to specific types of equipment.
Equipment suppliers and the customers should work hand in hand in order to ascertain which additional GEM capabilities should be incorporated for a specific type of equipment. Because the Capabilities defined in the GEM Standard are specifically developed to meet the factory automation requirements of semiconductor manufacturers, it is anticipated that most device manufacturers will require most of the GEM capabilities that apply to a particular type of equipment. Some device manufacturers may not require all the GEM capabilities due to differences in their factory automation strategies.
The scope of the GEM Standard is limited to defining the behavior of semiconductor equipment as viewed through a communications link. The SEMI E5 (SECS-II) Standard provides the definition of messages and related data items exchanged between host and equipment. The GEM Standard defines which SECS-II messages should be used, in what situations, and what the resulting activity should be.
The detailed interpretation of messages exchanged between SMART equipment and a host is defined in the SEMI Equipment Communications Standard (SECS-II).
This Standard is meant to be compatible with SEMI E4, Equipment Communication Standard(SECS-I) and alternative message transfer protocol.
This Standard defines messages at a very detailed level such that some host software can be developed with very little information on equipment as well as the equipment can be developed with very little knowledge of the host.
Most of the activities required for IC production are supported by the messages defined in the standards. These standards also outline the equipment-specific messages to support activities that are not considered by the standard messages. While some of the specific activities can be handled by common software in the host, it is expected that equipment-specific host software may be required to support the full capabilities of the equipment.
SECS-II defines the complete structure (form and meaning of the messages) of the messages exchanged between equipment and host with the help of a message transfer protocol, like SECS-I.
SECS-II defines the process of transferring the information between equipment and host in the form of messages. These messages are organized as per activities, called streams, which contain specific messages, called functions. A request for information and its corresponding data transmission is a simple example of such an activity.
SECS-II defines the structure of messages into entities called a list of items and items. This structure allows a self-describing data format that guarantees proper interpretation of the message.
The exchange of messages is governed by a set of rules for handling messages called the transaction protocol. The transaction protocol places some minimum requirements on any SECS-II implementation.
This Standard gives a means to independent manufacturers to produce equipment and/or hosts that can be connected without requiring specific knowledge of each other.
The SECS-I Standard lays a communication interface that is suitable for the exchange of messages between semiconductor processing equipment and a host. Semiconductor processing equipment includes equipment required for wafer manufacturing, wafer processing, process measuring, assembly, and packaging. A host is a computer or network of computers which exchange information with the equipment to accomplish manufacturing. This Standard includes detail information about the physical connector, signal levels, data rate and logical protocols required to exchange messages between the host and equipment over a serial point-to-point data path. This Standard does not define the data contained within a message. The meaning of messages is determined through a message content standard such as SEMI E5, Specification for SEMI Equipment Communications Standard 2 Message Content (SECS-II).
High-Speed SECS Message Services (HSMS) provides a way to independent manufacturers for producing implementations that can be connected and interoperate without requiring specific knowledge of one another.
HSMS is also intended as an alternative to SEMI E13 (SECS Message Services) for applications where TCP/IP is preferred over OSI.
It is intended that HSMS be supplemented by subsidiary standards which further specify details of its use or impose restrictions on its use in particular application domains.
HSMS defines a communication interface suitable for the exchange of messages between computers in a semiconductor factory.
Listed below the Subordinate Standards for SEMI E37:
SEMI E37.1-0819 — Specification for High-Speed SECS Message Services Single Selected-Session Mode (HSMS-SS)
SEMI E37.2-95 (Withdrawn 1109) — High-Speed SECS Message Services General Session (HSMS-GS)