Improving fab productivity with new standards for equipment data acquisition
01/01/2007
Deploying the set of new SEMI standards encompassing equipment data acquisition (EDA) enables the customization of requests by engineers and other fab personnel for equipment data. This enhanced ability to monitor equipment health and performance can directly improve fab productivity.
Trying to improve performance and productivity for semiconductor fabs and equipment used to involve searches for elusive equipment data and critical process information. Today, one no longer has to endure long waits while automation programmers answer requests for data to analyze and characterize equipment performance. This is because a new standard, the Equipment Data Acquisition (EDA) Interface, also known as Interface A, is available and ready to be deployed in manufacturing organizations.
Data collection
Because EDA allows more than one client to link to equipment through a secure, web-based network connection, many users and applications-including fab technicians, maintenance specialists, process engineers, and factory applications-can gather data simultaneously (Fig. 1). This capability enables productivity gains from increased overall equipment efficiency (OEE), fewer test wafers, reduced equipment process changeover, and minimal downtime. Increasing equipment productivity and manufacturing effectiveness is a challenge to most IC makers. ISMI’s experience in the semiconductor industry shows that manufacturing can become reliable and cost-effective if it is based on standards-oriented solutions that address current challenges while lowering factory cost of ownership (COO).
 Figure 1. EDA multiclient capability. |
As seen in Fig. 2, the areas of greater improvement are the ones related to OEE, particularly those with higher potential productivity gains such as maintenance, setup, and speed. The EDA interface brings to the industry a standard data collection solution based on proven technology that can significantly improve the equipment OEE and overall factory COO by providing more data at faster rates using secure communication to a wide variety of client applications.
 Figure 2. Sources of potential OEE improvement. |
To increase yield from current industry averages, the first step is to optimize manufacturing processes in ways that lower the number of wafer defects per square inch. An obvious solution-to increase wafer size-presents additional challenges, including uniformity, weight, new transport, and equipment requirements. Although an eventual transition to larger wafers may be justified, many chipmakers are looking for solutions that offer more immediate productivity gains. Making the most of an already depreciated and stable manufacturing environment provides a more immediate way to stay competitive by achieving productivity gains through OEE improvements (Fig. 2) and reduced COO.
Improved OEE through EDA
For semiconductor manufacturers, higher OEE means lower cost and higher productivity; for capital equipment suppliers, it means increased product differentiation. Both definitions can be met with access to high-quality data and precise process information to improve and resolve manufacturing challenges, methods, and processing needs. EDA was created to develop, operate, and deliver an information platform that follows standards and enables factories to use intelligent manufacturing.
Enabling world-class capabilities across the technology through seamless utilization of data at all levels of manufacturing and facility management was EDA’s ultimate goal. EDA brings these options to our factories through a new data pipeline that promises richer data, high data reporting throughput, and multiclient connectivity.
With EDA, the time needed to characterize a tool delivered to your dock is simplified by the new Common Equipment Model standard (SEMI E120), which allows fab engineers to check the equipment configuration, query its software modules for specific versions, and check the major component serial numbers and specifications. A process engineer, with help from the automation department, will be able to connect to the equipment after it has been installed and perform several operations:
- Check for supplier-defined data collection plans (SEMI E134) based on metadata defined for each major process module (SEMI E125).
- Discover what additional data can be collected to characterize the equipment and determine its process capabilities.
 Figure 3. Secure communication using SSL. |
A properly designed interface will identify all standardized state models defined by the most common standards for automation and control (SEMI E30, E87, E40, E90, E94, and E116). These state models, in turn, can be monitored by operations engineers or maintenance personnel, who can join the process engineer in connecting and creating their own data collection plans according to their needs. This capability eliminates the wait time for automation to come into place, the requirement for factory-specific programs to reside in expensive cell controllers, and the need for special personnel to integrate idiosyncratic requests within current fab architecture.
Ensuring secure data access
EDA provides mechanisms to use encryption to hide sensitive data and to safely request data from the equipment. Using secure sockets layer (SSL) internet security protocol as the base technique, the client establishes a secure session using certificates issued by the factory (certificate authority) so any data exchange is protected from phishing or spoofing (Fig. 3). Authorization is done through a simple but powerful privilege-and-role mechanism (SEMI E132) that defines specific client rights, allowing the client to use selected services defined in the EDA standards suite. Thus, factory data is controlled by those who use EDA capabilities, allowing for a variety of roles. For example, a process engineer can be assigned the highest rights, or be given rights that only allow use of specific data collection plans. Conversely, maintenance personnel and external users (such as suppliers) can be prevented from using and executing factory-specific data collection plans. Thus, privilege and role authorization in the EDA session management feature provides the IC maker with enough tools to build a secure environment to limit accessibility and functionality for many different types of users in the fab.
Metadata management
For those authorized, EDA provides a series of services relating to the equipment structure and metadata availability. This information is critical to creating the control interfaces to factory applications. Cell controllers are a good example of such interfaces. With the tool metadata descriptions, an automation engineer can quickly discover the number of loadports, material handling subsystems, and process modules within equipment. The metadata includes state model definitions provided by each tool component for collecting component or processing data (Fig. 4).
 Figure 4. Equipment metadata representation. |
At each metadata-described component (often called an equipment node), the user can discover which parameters to use to collect, control, or modify data during processing or equipment runs. With a set of five messages, the user can learn everything needed to characterize, automate, and qualify the equipment. This feature eliminates the time-consuming searches of automation engineers, who used to pore over outdated manuals trying to find the information a tool provided to satisfy process, operation, and maintenance requests. Also, it reduces times for tool ramp-up, process setup, and qualification, providing immediate productivity returns to chipmakers.
DCP management
Data collection plan (DCP) management (SEMI E134) allows a user to rapidly set up DCPs based on the equipment-provided metadata. All that is needed are: 1) a connection to the equipment through the EDA authorization and authentication feature, 2) access to the metadata, and 3) rights to create and activate the newly edited DCP. Such plans allow the user to include event, trace, and alarm requests on a persistent and/or cyclical basis. Plans can be buffered or reported at once, and one or more applications or clients can collect and receive data from a common DCP.
Another EDA feature includes a maximum-session parameter setting that allows the factory host to control the number of users who are allowed to connect to the equipment. This prevents the tool from being overwhelmed by too many clients requesting information. These and other novel capabilities are not available today on equipment that does not offer an EDA solution.
Once the user has access to equipment metadata, he or she can choose a specific process module or equipment subsystem from which to collect information and then selectively gather data to help troubleshoot an equipment component; monitor processes, equipment utilization, and performance; and compare such data to that of similar tools. This enables predictions on when a part may fail or whether a process is reliable and within specifications.
A global solution
The ultimate result from EDA deployment into manufacturing can make a huge difference in IC makers’ operations. With more data available from the equipment and flexibility to customize the request, engineers can gather only the information they need. The ability to monitor equipment health and performance directly impacts downtime and OEE, resulting in valuable productivity gains. Detailed monitoring of processing can lead to less scrap and fewer test wafers.
Moreover, data collection and equipment monitoring are no longer limited to automation departments or certain applications. With EDA, many authorized clients can access data directly from the tool, create their own data collection plans based on their current needs, and extract information to resolve problems and ensure high product yields.
 Figure 5. EDA data collection management. |
In summary, EDA offers: faster installations and commissioning to specification from an integrated hardware, control software, and networked environment; increased up-time, OEE, yield, and availability with field-proven, robust information to enable hardware, control software, and diagnostic solutions; higher throughput and data collection rates to allow applications and engineers to control and monitor processes efficiently; multiclient capability that allows multi-user benefits to data access and use; globally available support that allows automation maintenance at a relatively low cost; and enabling techniques to perform preventive maintenance only when necessary (as opposed to schedule-based systems).
Conclusion
The industry’s reception of EDA has been encouraging. In 2005, Microsoft announced its intent to support EDA adoption by developing architectural guidance to deliver Microsoft-based solutions. Leading equipment suppliers have implemented the EDA interface and delivered their solutions to IC makers interested in evaluating their tool’s new capability.
Third-party software suppliers also have made EDA available in their products. Adventa, AIS, Asyst, CenterPoint, Cimetrix, HCLT, and others all offer software modules that allow equipment suppliers to provide EDA capabilities to IC makers. Additionally, AMAT, Mattson, Novellus, SEZ, Thermo-Electron, Tokyo Electron, and other suppliers have also announced EDA availability for several of their tools. Today, IC makers can buy commercial client applications from suppliers such as CenterPoint, OSISoft, Wonderware, and others.
Support tools and products for developing web-based solutions from software companies have allowed EDA implementations to be completed in less than six months. The availability of experienced programmers and adoption in mainstream technologies such as XML, SOAP, and Web Services are allowing EDA to be developed and delivered with unprecedented speed-one of the greatest advantages of this new interface.
Gino Crispieri is a member of the e-Manufacturing Program at ISMI. SEMATECH, 2706 Montopolis Drive, Austin, TX 78741-6499; ph 512/356-7547, [email protected].