Self-reference template matching for wafer alignment

摘要

The accurate fabrication of devices in photolithography processes relies on proper overlay control. Wafer features are created via overlaying multiple pattern layers, and thus the patterns must he aligned correctly for the devices to be functional. Accurate alignment is also required in wafer metrology and inspection, wherein a metrology apparatus must be directed to the correct wafer location with a high level of precision for measurements to take place.