Wet process optimization to deposit conformal Cu diffusion barrier into TSV

This paper reports the use of SAM (Self Assembled Monolayer) formation to deposit the copper diffusion barrier into high aspect ratio TSV. SEM, AFM, water contact angle and zeta potential techniques have been used to better understand the surface functionnalization. Adhesion tape tests and SIMS analysis have been performed on Cu/NiP/SiO₂/Si coupons showing no limiting issue for further integration. Our results on TSV demonstrate the feasibility of wet process to get super conformal barrier deposit into high aspect ratio TSV.