Abstract: An interconnect structure includes a damascene structure, an inter-metal dielectric (IMD), a dielectric block and a metal via. The inter-metal dielectric layer is over the damascene structure. The dielectric block is embedded in the IMD layer and has a different etch selectivity than the IMD layer. The metal via is in the IMD layer and through the dielectric block to electrically connect the damascene structure.

Abstract: Methods of fabricating an integrated circuit device are provided. The method includes depositing a dielectric layer and a first hard mask layer in sequence over a substrate. The method also includes forming a patterned second hard mask on the first hard mask layer, and forming a third hard mask portion in an opening of the patterned second hard mask. The method further includes removing the patterned second hard mask to leave the third hard mask portion on the first hard mask layer, and etching the first hard mask layer to form a patterned first hard mask. In addition, the method includes etching the dielectric layer by using the patterned first hard mask as an etching mask to form trenches in the dielectric layer, and filling the trenches with a conductive material to form conductive lines.

Abstract: An interconnect structure includes a damascene structure, an inter-metal dielectric (IMD), a dielectric block and a metal via. The inter-metal dielectric layer is over the damascene structure. The dielectric block is embedded in the IMD layer and has a different etch selectivity than the IMD layer. The metal via is in the IMD layer and through the dielectric block to electrically connect the damascene structure.