Wafer Edge Inspection and Metrology
This inspection process focuses on the area near the wafer edge, an area that poses difficulty for traditional frontside inspection technology due to its varied topography and process variation. This inspection step is implemented during ADI, post-etch, post-clean and post-CMP.

Typical defects include:

• Peeling films
• Residual slurry or photoresist
• Cleaning contaminants
• Residual films
• Surface and embedded defects
• Edge Bead Removal and Bevel Clean metrology

Edge Bevel Inspection (Edge Normal)
This inspection focuses on the side edge of a wafer to determine if it has any chips, cracks, contamination or layering delamination. This process identifies wafers that have a risk of breaking, and catches them early to prevent them from breaking at a point in the process where they might cause contamination for other wafers and equipment. Edge Bevel Inspection can be implemented at any point throughout the wafer manufacturing process.

Typical defects include:

• Chips
• Cracks
• Contamination
• Layering delamination
• Residual photoresist

Edge Bead Removal (EBR) and Bevel Clean Metrology
This edge film boundary measurement is required exclusively in the photolithography process, primarily to determine if wafers have been properly aligned for the creation of the edge exclusion region. This process also verifies that the EBR and bevel clean process worked as intended. EBR metrology measures the distance from the wafer apex to the edge of the resist film at up to 360 points around the wafer circumference. Bevel clean metrology measures the distance from the wafer topside to the film boundary at up to 360 points around the wafer circumference.