Overview
Clean is not a property. It is a specification outcome.
A wafer, surface, component, chemical or tool is not “clean” in a universal sense. It is clean only relative to a defined purpose, risk model and measurement method.
This whitepaper introduces a practical framework for defining “clean enough”, aligning engineering and management expectations, and reducing misunderstandings between suppliers, fabs and internal stakeholders.
The framework treats cleanliness as a production-system question: the incoming contamination state, cleaning process, tool background, handling, storage, inspection and sampling strategy all influence whether the required condition is achieved and preserved.
Topics covered
- Defining cleanliness: clean for what, clean from what, and clean when.
- Cleanliness Vector: contamination class, threshold, measurement method and controlled location.
- Cleanliness Definition Sheet: translating a vague requirement into a usable engineering specification.
- Inspection and sampling: choosing methods and sampling rules that make results comparable and useful for process control.
- Manufacturing context: tool hygiene, process-chain effects, failure mechanisms and the economics of “cleaner”.
Central implementation point: cleanliness succeeds when definition, verification, inspection and sampling form one consistent system.