Today, a typical semiconductor 300mm front end fab may require thousands of process and metrology tools to build up a wafer die into an impressive and flexible device component. Each of these tools is incredibly complex and very specific in nature and each of these together must be orchestrated carefully to ensure overall equipment effectiveness (OEE).
Millions of Parts
To illustrate the maintenance & spare parts complexity, consider the photolithography process. At the photomask disposition step, masks used to expose film at Litho must be carefully inspected for defects under scanner-like conditions. The Zeiss AIMS Inspection tool is one example of this. For this specific tool, there are over 4,500 subsystems and 64,000 individual parts from 134 different suppliers. This is an incredible array of parts and a monumental management challenge—not only with the supply chain but also with the maintenance and effort involved with associating parts and part numbers (P/Ns).
The Right Part at the Right Time
To manage this complexity, fabs must ensure parts availability. For all the thousands of tools and millions of spare parts, many of the most needed or replaced parts are available in-house, either within the fab or at a short distance nearby where parts are housed and ready for use in a local “Stores” warehouse. Other longer lead time parts are shipped and ordered as needed from OEM and 3rd party suppliers.
All this part complexity contributes to the OEE of an individual tool because parts and P/Ns must be associated with maintenance work done on the tool. When a maintenance work order is planned or triggered for a tool in a fab, the required spare parts must be available and associated with that work order. Given the risk of not having the right part at the right time for maintenance, a need exists to efficiently manage the association of P/Ns to maintenance work orders in a way that reduces complexity and ensures the right part at the right tool.The Exchange of Part Information
To illustrate this part association process, figure 1 shows the flow of parts during staging and maintenance phases, divided into physical and logical systems. With physical systems, shown at the bottom, parts move from actual suppliers, to warehouses, and then to tools. To facilitate the automation management of spare parts to maintenance work orders we show the necessary logical flow as well, in which a massive volume of spare parts inventory, typically maintained by an ERP system, must exchange P/N information with the maintenance management system. This overlap and exchange of data between these two systems requires careful coordination and system integration to ensure the right part at the right tool for maintenance.
Applied Materials has a well-known maintenance management capability that is built on Xsite™ technology, which is used to efficiently automate maintenance schedules and track tool maintenance performance based on SEMI E10 states. This tracking ability provides a means of measuring OEE in terms of MTBF and MTTR metrics, which are captured automatically during maintenance when using the Xsite technology.
What Customers Have Told Us
To enhance this maintenance management capability, we’ve worked closely with our customers to identify the key challenges which arise from the integration of spare parts to maintenance.
- Automating and managing spare parts association to maintenance work orders
- Reduce system complexity by allowing the P/N to move between these two systems
- Providing faster-out-of-box integration with the ERP system
With these three customer priorities in mind, we have released two optional modules, Spares and ERP, both of which are available today with maintenance management. Figure 2 highlights both these modules in the Xsite technology framework.
What Do These Modules Do?
The Spares module is based on the well-known INV module and does the following:
- Associates work orders to P/Ns (both serialized and consumable parts)
- Consumes spares during PMs
The ERP module:
- Standardizes the data dictionary and Server-Side Rules (SSRs) for fast out-of-box integration with ERP
- Allows P/N tracking history and queries
- Ensures P/N consumption and returns to ERP
What are the Benefits in a Semiconductor Fab?
Essential benefits of these modules for manufacturers include:
- Data traceability (P/N association and usage counts)
- Improved MTTR by providing the right part at the right time through P/N to work order association, which reduces maintenance down time
- Lower ERP integration cost by providing standard touch points and simple SSR configuration
- Reduced complexity — P/Ns move between systems and do not need to exist in both places
- Improved OEE—spares outliers can be identified because P/Ns can be queried and associated to out-of-bounds MTBF metrics
