Yoshinori Hagio*, Ichirota Nagahama, Yasuo Matsuoka, Hidefumi Mukai and Kohji Hashimoto
Process & Manufacturing Engineering Center, Toshiba Corporation, Semiconductor Company
8 Shinsugita-cho, Isogo-ku, Yokohama-shi 235-8522, Japan
We have constructed a hotspot management flow with die-to-database (D2DB) inspection systems of device patterns fabricated by spacer patterning technology, which is a strong candidate among various kinds of double patterning technologies expected for applying in the manufacture of NAND Flash memories below 3x-nm-half-pitch generation. At the SPIE conference in 2006, we stated that “Hotspot management” is a management flow to extract fatal defects in lithography, that are called “hotspot”, by computer calculation with a fast full-chip lithography simulator and to feed back the results to optical proximity correction to clean up the hotspot for making device masks with enough lithography margin. The spacer patterning technology, still remains difficulties due to the complexity in a process from printed image to final physical patterns. Many of real hotspots appear not just after the lithography but after the transfer etching. It is, therefore, difficult to capture all the hotspots and to disposition hotspots in the SPT. For the construction of an effective hotspot management flow for spacer patterning technology,, it is extremely effective to inspect a processed wafer with a D2DB system. In this work, we apply novel D2DB e-beam inspection system NGR-2100. As the NGR-2100 is developed for this purpose, it has improved performance in operating time even for the full-chip inspection.
NGR-2100 has a FOV (field of view) much wider than conventional CD-SEM. It is found that the hotspot management flow described in this paper can extract hotspots with a size down to 10 nm through the spacer patterning process. In this paper, we will demonstrate the hotspots fixing and clean up cycle with improved turn-around time.
Keywords: Spacer patterning process, Die-to-database inspection, Hotspot management, DFM