Structures of electronic fuses (e-fuse) are provided. An un-programmed e-fuse includes a via of a first conductive material having a bottom and sidewalls with a portion of the sidewalls being covered by a conductive liner and the bottom of the via being formed on top of a dielectric layer, and a first and a second conductive path of a second conductive material formed on top of the dielectric layer with the first and second conductive paths being conductively connected through, and only through, the via at the sidewalls. A programmed e-fuse includes a via; a first conductive path at a first side of the via and being separated from sidewalls of the via by a void; and a second conductive path at a second different side of the via and being in conductive contact with the via through sidewalls of the via.