A method of forming a dual damascene structure on a substrate having a
dielectric layer already formed thereon. In one embodiment the method
includes depositing a first hard mask layer over the dielectric layer;
depositing a second hard mask layer on the first hard mask layer;
depositing a third hard mask layer on the second hard mask layer and
completing formation of the dual damascene structure by etching a metal
wiring pattern and a via pattern in the dielectric layer and filling the
etched metal wiring pattern and via pattern with a conductive material.
In one particular embodiment the second hard mask layer is an amorphous
carbon layer and the third hard mask layer is a silicon-containing
material.