E-beam inspection of EUV programmed defect wafers for printability analysis

Understanding the effect of defect sizes and their impact on EUV lithography is an ongoing challenge due to continued scaling of devices [1], [2]. The objective of this study is to assess printability of defects on post develop photoresist wafers and their detection capability with an electron beam inspection tool on EUV resist for various patterns (Line/Space, Contacts). Total capture of defects is an important factor for assessing printability on photoresist patterned wafers and monitoring process window. In this work, we present a comparison of Die to Die (reference to programmed defect to sites on wafer) and Die to Database (program defect sites on wafer to design). A programmed defect test mask is used to understand the impact of printing mask defects at multiple lithography levels (ex. gate, metal etc.) at 20 and 14nm technology ground rules. It is designed with both additive and subtractive features at defect sizes ranging from 30nm to 1nm. The defect inspection tool parameters such as averaging, threshold value were varied to assess its detection capability.