A method of fabricating a stacked structure for forming a damascene
process is described. A doped dielectric layer is formed on a substrate.
A surface treatment is performed to the dielectric layer to make the
dopant concentration in an upper surface layer of the dielectric layer
lower than that in the other portions of the dielectric layer. A metal
hard mask is then formed on the dielectric layer. Since the dopant conc.
in the upper surface layer of the dielectric layer is lowered, the
reaction between the metal hard mask and the dopant in the dielectric
layer can be inhibited.