Patent ID: 7524749

Claim:
A method for forming a metallization contact in a semiconductor device, comprising the steps of: forming an insulating layer over a semiconductor substrate including an active device region or a lower metal wire; forming a contact hole to expose a portion of the active device region or lower metal wire by etching a portion of the insulating layer; depositing a first TiN layer on the insulating layer and inside the contact hole by a PVD process using a first carrier gas composition of nitrogen (N 2 ) and argon (Ar), the first TiN layer having a first density controlled by the first carrier gas composition; depositing a second TiN layer directly on the first TiN layer by a PVD process using a second carrier gas composition of nitrogen (N 2 ) and argon (Ar), the second TiN layer having a second density controlled by the second carrier gas composition; and forming a metal layer on the second TiN layer, wherein the second carrier gas composition has an N 2 -to-Ar ratio different from that of the first carrier gas composition.