About the project
Accurate pre-alignment of wafers is key for each individual processing step. Contactless wafer edge measurement requires a dedicated vision system. Demcon has developed an image based measurement system that is capable of statically and dynamically detecting the edge of wafers with respect to the gripper and wafer table marker. Using a custom optical design we are able to combine the gripper marker, the wafer marker and the wafer edge into one image without the need for lens calibration.
This resulted into sub-micron accuracy in all three dimensions with extended depth of focus and flat field. One of the key enablers for such performance is the use of custom optical and opto-mechanical designs for imaging and through-the-lens-illumination in combination with vision algorithms.
Demcon Focal is highly experienced in sub-μm measurements and alignment applications. Amongst others, this also includes accurate mask alignment, high demanding imaging lens calibration techniques and small defect detection.
- Up to 6 mm out-of-focus, precision XY < 1 mμ
- Up to 12 mm out-of-focus, precision XY < ~2 mμ
- 24 mm field-of-view with TTL illumination