Method of forming metal interconnection and method of fabricating semiconductor device using the same

Low-k dielectric layer (low-k dielectric layer) deposition step, forming a trench (trench) for the low-k dielectric layer, forming a barrier layer (barrier layer) in the trenches, comprising the steps of filling a metal on said barrier layer, a step of forming a flattening (planarization) step, and a capping layer (capping layer) on said planarized metal for the metal, and the capping layer is disclosed a semiconductor production process comprising at least two layers.