Edge Rounding
Edge Rounding is a wafer finishing process that smooths sharp corners at the wafer edge to reduce chipping, particle generation, and film stress during processing.
## What Is Edge Rounding?
- Method: Chemical-mechanical polishing or wet etching of wafer bevel
- Profile: Transitions sharp 90° corner to rounded ~45° bevel
- Timing: After wafer slicing, before device processing
- Specification: Typically 200-400μm radius
## Why Edge Rounding Matters
Sharp wafer edges concentrate mechanical stress, leading to chips that contaminate entire lots. Rounded edges reduce breakage by 50%+ during handling.
Edge Rounding Benefits:
- Reduced edge chipping during robot handling
- Better epitaxial film uniformity at edge
- Reduced particle generation during CMP
- Lower film stress at wafer periphery
- Fewer handling-related scratches