Surfscan 6420 Particle Defect

Laser-based surface inspection systems of this type detect particles and defects on bare or unpatterned semiconductor wafers. Such systems are used in semiconductor fabrication for contamination monitoring and process control.

The system scans the wafer surface in a raster or spiral pattern, building a defect map that can be compared against cleanliness thresholds. The instrument typically provides both dark-field and bright-field channels to differentiate particles from surface roughness.

In the semiconductor manufacturing flow, unpatterned wafer inspection such as this is performed after cleaning, deposition, or other processes that can introduce particulates. The tool monitors bare wafers or monitor wafers that run through process steps to verify low particle levels.

The inspection results guide process engineering decisions, such as whether a cleaning step is effective or if a tool is generating particles. The data are also used for yield improvement and equipment qualification.

The primary application is particle and defect detection on bare silicon wafers, including monitor wafers used for process certification. The system is also used in research and development to study defect formation.

Additional applications include inspecting wafers after chemical-mechanical polishing, film deposition, and etch processes to check for micro-scratches and residual particulates.