E-Diagnostic Systems from Nikon Keep NSRs Operating at Peak Condition

As we continue to move to smaller and smaller geometries, lithography equipment has become more complex and increasingly expensive. Now more than ever, IC manufacturers need to keep their steppers and scanners running within specifications at all times. To help customers keep their NSRs operating at peak condition with the maximum availability and productivity, Nikon has developed a suite of powerful diagnostic and performance monitoring systems that include Multi-User Remote Connectivity (MRC), Remote Equipment Monitoring (REM), and the Lithography Equipment Engineering System (LEES). These systems are being used extensively by Nikon and customers worldwide.

MRC is an internal Nikon tool that enables comprehensive remote access to steppers and scanners within the fab. Machine log files can be accessed to support detailed offline analysis by Nikon; remote application of software upgrades/patches can be performed; and if necessary, MRC can also be used for remote operation of the NSR. The REM system is another internal Nikon analysis and charting tool that resides within the Nikon network and receives data that is pushed to it from our customer sites. Nikon Service and Engineering personnel across the United States and Europe utilize these sophisticated e-diagnostic tools to monitor tool performance for proactive/predictive NSR maintenance and to reduce equipment mean time to repair (MTTR), as well as to provide offsite support and diagnosis on escalated stepper or scanner problems. MRC and REM support are available to any Nikon customer with a service contract in the US or Europe, with no additional charge for this heightened level of tool monitoring. (Network setup for MRC and REM access is required on the customer side.) Nikon is also able to work with third party connectivity solutions, if that is preferred.

Going beyond internal Nikon REM capabilities, LEES is offered as a customer product that provides data acquisition, analysis, and charting capabilities for your team at your facility, and has been operating in leading-edge manufacturing facilities around the world since 2004. Data is collected from the NSRs in the fab, and LEES then stores the information in a database providing customers the flexibility to trend and monitor a wide variety of system parameters. Additionally, control limits can be defined to trigger messages sent directly to the tool owner or other key individuals. LEES improves system availability and reduces rework by providing near real-time information about a problem, as well as flagging impending issues ahead of time.

Figure 1. Nikon has developed a suite of powerful diagnostic and performance monitoring systems for MCSV/MCSW-based NSRs that include Multi-User Remote Connectivity (MRC), Remote Equipment Monitoring (REM), and the Lithography Equipment Engineering System (LEES).

In the following usage case, it was noticed during LEES dashboard monitoring that an SX08 system was exhibiting instability in wafer rotation results. Further investigation highlighted this was actually driven by a difference between the first wafer and the remainder of the wafers within the lot (left image below), and root cause investigation identified an issue with the prealigner, which was subsequently corrected (right image). Nikon Service engineers now routinely monitor the necessary data across REM and LEES-connected SX08 systems for this signature as an indictor of impending prealigner issues, thereby minimizing downtime effects through proactive parts order and replacement.

Figure 2. LEES dashboard monitoring highlighted instability in wafer rotation data. Further investigation identified differences between first wafer and subsequent wafers in the lot (left image). LEES data confirmed the issue was resolved following part replacement.

As another usage example - for preventative maintenance purposes, Nikon Service engineers routinely monitor SX05 systems on REM and LEES for a particular loader robot error that is an indication of an impending hardware failure. To replace the entire associated unit at the point of failure would cost on the order of $20,000. In contrast, proactive monitoring and repair of the specific subcomponent before it fails will cost significantly less and have a minimized impact on manufacturing, when performed as a scheduled event. Besides monitoring for hardware related issues, Nikon can also use REM and LEES to flag errors or trends that indicate problems with NSR process recipes and quickly alert the customer to minimize the production impact.

In addition to providing remote support, Nikon Applications engineers and Service Operations representatives also use e-diagnostics for detailed productivity monitoring, and in customer-specific improvement programs focused on areas such as alignment optimization. REM and LEES can provide breakdowns of how the NSR is utilized throughout the day or week, and deliver invaluable information on assist types or rates, which not only indicate potential system issues, but also highlight process specific problems. In conjunction with aiding troubleshooting efforts, these advanced e-diagnostic tools identify key areas of opportunity to maximize NSR efficiency and output, which the fab would then focus engineering resources on.

Figure 3. REM and LEES can provide breakdowns of how the NSR is utilized throughout the day or week (left image), and identify key areas of opportunity, which the fab would then focus engineering resources on.

Nikon has developed a suite of powerful diagnostic and performance monitoring systems that we are using extensively with our customers to maximize fab performance and productivity. We are eager to partner with you to determine which of these solutions would be most beneficial to your manufacturing facility. Please contact accountsupport@nikon.com for more information.