Tri-layer process is the one of the key technique both for the lithography and etching around Hp20nm patterning. In applying for tri-layer process, we are focusing on inorganic type under layer which mainly containing Si atoms. This Si type hard mask (Si-HM) can perform not only as the Lithography performance enhancement layer for fine pitch, but also as the etching hard mask against bottom layer (spin on carbon : SOC). In this paper, we propose our new Si-HM concepts to achieve high sensitivity, wide process window and good line edge roughness. The key point of our concepts is EUV sensitive unit in Si-HM. Our EUV sensitive unit strongly promotes acid generation from PAG of EUV photo resist. Especially, for EUV NTD lithography process, EUV sensitive unit can perform as the adhesion enhancer between Si-HM and photo resist at EUV exposed area. As this result, we could resolve 22nm L/S=1/1 pattern on the EUV sensitive Si-HM by EUV NTD process even in the condition which hp40nm was the resolution limit with HMDS treated Bare-Si / PR stack. Moreover, from the view point of etching hard mask, 30nm dense L/S pattern and 20nm semi iso line pattern could be transferred to SOC layer successfully. We will present our latest Si-HM performance specialized for EUV lithography.

Date Published: 1 April 2013
PDF: 8 pages
Proc. SPIE 8679, Extreme Ultraviolet (EUV) Lithography IV, 867914 (1 April 2013); doi: 10.1117/12.2011441

Published in SPIE Proceedings Vol. 8679:
Extreme Ultraviolet (EUV) Lithography IV
Patrick P. Naulleau, Editor(s)