Ki-Kwan Park

Highly reliable Cu interconnect strategy for 10nm node logic technology and beyond

CVD-Ru represents a critically important class of materials for BEOL interconnects that provides Cu reflow capability. The results reported here include superior gap-fill performance, a solution for plausible integration issues, and robust EM / TDDB properties of CVD-Ru / Cu reflow scheme, by iterative optimization of process parameters, understanding of associated Cu void generation mechanism, and reliability failure analysis, thereby demonstrating SRAM operation at 10 nm node logic device and suggesting its use for future BEOL interconnect scheme.

Superior Cu fill with highly reliable Cu/ULK integration for 10nm node and beyond

It is possible to overcome Cu void issues beyond 10nm node device by adapting CVD-Ru liner instead of conventional PVD Ta liner. However, CVD Ru liner integration degrades TDDB performance without optimizing its scheme. In this paper, superior gap-fill performance without TDDB performance degradation will be described in our optimized integration scheme along with a proposal for the mechanism of TDDB degradation in the Ru integration scheme. CVD-Ru liner is the prime candidate for Cu metallization at 10nm node and beyond.

High performance Cu/low-k interconnect strategy beyond 10nm logic technology

CVD-Ru based reflow Cu scheme demonstrates robust gap fill performance at 10nm and 7nm node equivalent patterns. Potential EM and TDDB reliability concerns associated with Ru CMP are identified and successfully addressed by the application of new processes and materials. This suggests our proposed scheme can be one of promising candidates for 10nm node logic device and beyond.

Alleviating electromigration through re-engineering the interface between Cu & dielectric-diffusion-barrier in 90 nm Cu/SiOC (k=2.9) device

Despite the initial success in integrating a 90 nm Cu/SiOC (k=2.9) device using the HSQ via-filler scheme, the reliability issues remain. By correlating electromigration (EM) with the moisture blocking capability of the dielectric-diffusion-barrier, we target the factors contributing to the moisture blockage, namely, the N and H-content within SiC. Consequently, increasing the N/H ratio in the SiCN film, we demonstrated a significant enhancement in EM reliability.