Backside Defect Monitoring Strategy and Improvement in the Advanced Semiconductor Manufacturing

Traditionally, control the defect on the front of wafer can improve equal yield because all chips located wafer's upper part. That's why wafer manufacturing engineers always focus on front side and bevel of wafer. However, with the rapid development of semiconductor technology, slight variation of backside condition may induce yield loss. Against this backdrop, monitoring the backside of wafer will be extremely important. Monitoring method include visual inspection (VI), macroscopic inspection (MAI), microscopically inspection (MII) and hyper fine inspection (HFI). All the above methods cross banded by different process characteristic build a multi-stage monitor system. There are a lot of challenges in backside inspection result from scanning algorithm. Monitor arrangement scientifically was elaborated in this paper. Meanwhile, graphic recognition system was introduced which can quantify the backside scan image and distinguish exceptions. Finally, the scan result can check and clear a fault after compare with the Backside Database (BDB). Certainly, use ingenious printing to collect the BDB was also discussed in this content.