A method for forming a metal wiring of a semiconductor includes forming an
inter metal dielectric layer on a semiconductor substrate having a
predetermined low structure with a conductive layer. A plurality of
contact holes is formed to expose the conductive layer through the inter
metal dielectric layer. A first titanium nitride layer is formed on
sidewalls of the contact holes. The first titanium nitride layer is
plasma processed. A first titanium silicon nitride layer is formed on the
first titanium nitride layer. Metal plugs are formed on the first
titanium silicon nitride layer. The metal plugs, the first titanium
silicon nitride layer, and the first titanium nitride layer are polished
to expose the inter metal dielectric layer. Metal wirings are formed to
cover the contact holes.