| abstract |
A dielectric layer is formed on the substrate, an anti-reflection layer is formed on the porous dielectric layer, and a first hard mask is formed on the anti-reflection layer. An anti-reflection layer and a first hard mask are used as a mask material to form via openings and trench openings in the porous dielectric layer. After the via hole opening and the trench opening are formed, the first hard mask is removed. An interconnect is formed in the opening, and the interconnect has a guide hole, the guide hole has a contour angle between about 70 degrees and about 80 degrees, and a depth ratio between about 65% and 70% . |