A Semiconductor Photolithography Overlay Analysis System Using Image Processing Approach

In semiconductor manufacturing, photolithography is one of the most important processes. To control the overlay errors, which is one of the key factors related to good production quality in this process, an Overlay Analysis System is proposed in this paper to help analyzing the overlay variations based on image processing approach. By comparing current running production lots with existing cases in the case base, the parameters required for overlay process control in photolithography process can be analyzed without effecting the process throughput as some other existing approaches.