Semiconductor device having copper metal line and method of forming the same

A method of forming a copper (Cu) metal line in a semiconductor device, said method comprising the steps of:

• an intra-metal dielectric (IMD) deposition step of depositing an interlayer insulating layer on a semiconductor substrate in which a lower metal line is formed;
• a photo process and an etch process step of forming a via contact hole and a metal line pattern in the semiconductor substrate;
• a seed deposition step of sequentially depositing a metal barrier film and a seed copper (Cu) film;
• an electrochemical plating (ECP) step of forming a copper (Cu) film on a surface of the semiconductor substrate by an electrochemical plating (ECP) method;
• a chemical mechanical polishing (CMP) step of removing the copper (Cu) film and the metal barrier film, other than the portion of a copper metal line to be formed, from the semiconductor substrate having the copper (Cu) film formed thereon, by means of a chemical mechanical polishing (CMP) process;
• a pre-deposition processing step of removing a native oxide film existing on a surface of the copper (Cu) metal line of the semiconductor substrate;
• a silicon deposition step of depositing a silicon (Si) layer on the surface of the copper metal line of the semiconductor substrate by an atomic layer deposition method;
• an annealing step of making the deposited silicon layer and copper (Cu) metal react to each other to form a copper (Cu) silicide layer;
• a wet etch step of removing a remaining silicon layer without being reacted in the annealing step;
• and
• an insulating anti-diffusion film deposition step of depositing an insulating anti-diffusion film over the semiconductor substrate;
• wherein the silicon layer deposited in the atomic layer deposition method of the silicon deposition step has a thickness ranging from 10 to 20 angstrom.