Method for forming metal plug

摘要

Disclosed is a method of forming a metal plug which selectively forms the metal plug within a contact hole or a via hole in a simple manner. The method of the invention comprises the following steps of: (a) forming an insulation film having a contact hole on a lower structure, the contact hole exposing the lower structure; (b) forming a diffusion barrier with a uniform thickness on the whole surface of the resultant structure of the (a) step; (c) exposing the resultant structure having the diffusion barrier to an oxygen plasma atmosphere or an ozone plasma atmosphere to form a nucleation-preventing film made of an oxide on the surface of the diffusion barrier outside the contact hole; and (d) depositing a metal only inside the contact hole via a CVD to form the metal plug. According to the present invention, the manufacturing yield is improved whereas the manufacturing cost thereof is saved.