[K-6] MEMS and Advanced Metallization I

[K-6-06] 18nm pitch EUVL Line/Space double-patterning exploration for N3 BEOL

〇Stephane LARIVIERE¹, Stefan DECOSTER¹, Sara PAOLILLO¹, Vincent RENAUD¹, Diana TSVETANOVA¹, Bart KENENS¹, Hanne DE COSTER¹, Quoc Toan LE¹, Yusuke ONIKI¹, Alfonso SEPULVEDA MARQUEZ¹, Karen STIERS¹, Felix SEIDEL¹, Martin O'TOOLE¹, Mircea DUSA¹, Kurt RONSE¹, Chris WILSON¹ (1. imec (Belgium))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.K-6-06

At N3, metal interconnect logic Back End of Line (BEoL) wiring could not be Cu metallization anymore as resistance will dramatically increase due to the Critical Dimension (CD) downscaling. Many studies have identi-fied Ruthenium (Ru) as a relevant alternative metal, which, with a suitable hard mask (HM), can be directly patterned at that node in a dry etch scheme (Direct Metal Etch, aka DME). Waiting for 0.55 high-NA EUV single exposure availability, multi patterning schemes circum-vent the challenge of chip scaling down to 18 nm pitch (MP18) gratings.
In this work, we will present the development of a double patterning EUV flow for sub-20 nm L/S (line/Space) where the HM grating output is delivered to etch design-friendly variable metal CD lines with DME.