In-Situ Defect Detection Practical Considerations and Results

In-Situ Defect Detection Practical Considerations and Results

Timothy Potts
Dark Field Technologies, Inc.

"The need to inspect films and glass, during deposition, is crucial. Barrier films and other high-value films for flexible electronics and displays must be contaminant free, and in-situ inspection for defects of 1µm and larger is required in real time. Currently, deposition is performed “blind” – there is no feedback for contamination or defect detection until after the roll or sheet has been produced. Off-line inspection means rewinding and handling – adding to the cost and the risk of creating more defects. In-situ inspection must contend with many challenges including vacuum conditions inside the chamber, space constraints, alignment challenges and other factors. A special high-resolution Solid State Laser Reflection (SSLR) design has been completed and proven for in-situ inspection at resolutions to 1.5µm. All active modules are located outside the chamber. This self-aligning system delivers RTR or sheet-based inspection inside the chamber, in transmission, reflection or both. System theory will be explained, application examples will be given and practical/critical installation considerations will be presented.