Semiconductor device and manufacturing method thereof

摘要

An interconnect trench is formed on a dielectric layer 12 and a first HSQ layer 14 formed on a semiconductor substrate, and a tantalum family barrier metal layer 24a is formed all over the substrate. Then a seed copper-containing metal layer 60 and a plated copper layer 62 are formed so as to fill a part of the interconnect trench. After that, a bias-sputtered copper-containing metal layer 64 is formed on the plated copper layer 62 so as to fill the remaining portion of the interconnect trench and then heat treatment is performed. As a result, a dissimilar metal contained in the bias-sputtered copper-containing metal layer 64 diffuses uniformly into the plated copper layer 62.