Challenge: Recipe verification

Nowadays high-tech manufacturing recipes have become tremendously complex so that it is hard even for experienced process engineers to detect all potential contractions inside a process flow, especially as process sequences become longer and longer. Therefore the manual review of runcards and planned DoEs has become a tedious, time consuming and sometimes even error prone task.

Wrongly placed decimal points in manually generated runcards, inconsistent updates of submodules in a flow, material inconsistencies or incompatibilities are increasingly difficult to spot and can cause whole batches to be unuseable or, in extreme cases, even damage or contaminate the manufacturing equipment.

Solution:

In the verification phase of a newly assembled or modified process flow, a software system can show its full capabilities in checking the manufacturability of process flow. Most of the rules and knowledge used by an experienced process engineer (e.g., clean before deposition and do not exceed 150°C as long as a polymer for lithography is deposited at the wafer) have a form that can be expressed in a computer-readable way. So if a domain expert enters the rules for his/her process steps, they can be used by all engineers to check a newly developed process flows before manufacturing them in the line. This means that XperiDesk is able to manage rules, connect rules with Boolean terms (i.e., and, or and not) and XperiFication is able check process flows using these rules. These rules can then be used to check the complete manufacturing flows and can spot problems even if early and final steps influence each other. This way issues concerning contamination, material dependencies, temperature budgets, to name a few, can be automatically checked and problems and potential problems highlighted and alerted to the process engineers. Additionally the XperiDesk system enhances the collaboration and enables engineers to do peer reviews even when working at different sides of the globe.