Edge placement error measurement in lithography process with die to database algorithm

• Main Authors: Sato, Yoshishige, Huang, Shang-Chieh, Maruyama, Kotaro, Yamazaki, Yuichiro
• Format: Conference Proceeding
• Language: English
• Published: SPIE 11.04.2019
• ISBN: 9781510625655; 1510625658
• ISSN: 0277-786X
• DOI: 10.1117/12.2515143

The control of edge placement error (EPE) is playing key role in the patterning of advanced technology node in semiconductor industry. EPE is evaluated by the metric of overlay, distance of patterns between two layers in multi patterning, and patterning error in local area. In past instance, overlay between upper layer and underlayer was measured by electron beam (e-beam) metrology system with scanning electron microscopy (SEM) image. EPE which is caused by local patterning error on photoresist layer is influenced by scanner tool parameters such as focus and exposure. Technology and method of EPE measurement on photoresist layer is highly required to optimize scanner tool performance. This study provides the measurement method of EPE on photoresist layer resulting from variation of scanner tool condition. Definition of EPE in this study is the distance between contour of SEM pattern and contour of target layout. Die to Database (D2DB) technology which compares image and layout data was applied to this study with large image size which include huge number of patterns. The advantage of the method was confirmed by the experiment on the verification of local patterning error. The result of the experiment shows scanner tool conditions are well represented by these local patterning errors. In addition, optimizing scanner parameters and monitoring scanner condition by these local patterning errors are proposed.