Conformal Deposition and Gap-Filling of Copper into Ultranarrow Patterns by Supercritical Fluid Deposition

Supercritical fluid deposition (SCFD) of Cu onto ultranarrow vias (50 to 220 nmφ and 1 µm depth) was studied with using angled polishing for future ultralarge scale integration metallization. SCFD conformally fabricated a smooth, continuous, and 10-nm-thick Cu film in ultranarrow vias. Excess H 2 compared with the precursor as well as surface saturation of the precursor enabled uniform nucleation and conformal deposition. Highest H 2 concentration in this study (0.39 mol/L) promoted the nucleation density, resulting in formation of a smooth and continuous film. In conclusion, SCFD successfully achieved complete filling without any voids onto via patterns.