Translator Disclaimer
23 March 2009 CD-SEM tool stability and tool-to-tool matching management using image sharpness monitor
Author Affiliations +
As device feature size reduction continues, requirements for Critical Dimension (CD) metrology tools are becoming stricter. For sub-32 nm node, it is important to establish a CD-SEM tool management system with higher sensitivity for tool fluctuation and short Turn around Time (TAT). We have developed a new image sharpness monitoring method, PG monitor. The key feature of this monitoring method is the quantification of tool-induced image sharpness deterioration. The image sharpness index is calculated by a convolution method of image sharpness deterioration function caused by SEM optics feature. The sensitivity of this methodology was tested by the alteration of the beam diameter using astigmatism. PG monitor result can be related to the beam diameter variation that causes CD variation through image sharpness. PG monitor can detect the slight image sharpness change that cannot be noticed by engineer's visual check. Furthermore, PG monitor was applied to tool matching and long-term stability monitoring for multiple tools. As a result, PG monitor was found to have sufficient sensitivity to CD variation in tool matching and long-term stability assessment. The investigation showed that PG monitor can detect CD variation equivalent to ~ 0.1 nm. The CD-SEM tool management system using PG monitor is effective for CD metrology in production.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hideaki Abe, Yasuhiko Ishibashi, Yuichiro Yamazaki, Akemi Kono, Tatsuya Maeda, Akihiro Miura, Shunsuke Koshihara, and Daisuke Hibino "CD-SEM tool stability and tool-to-tool matching management using image sharpness monitor", Proc. SPIE 7272, Metrology, Inspection, and Process Control for Microlithography XXIII, 727210 (23 March 2009);

Back to Top