dedicated fuse layer typical ic chip elements are formed on one or more circuit layers e g a surface silicon layer 130 of a chip formed in a silicon on insulator soi wafer the fuse 122 connects to a circuit in the circuit layer 130 or layers through wires 132 134 136 138 in a number 2 in this example of intermediate wiring layers 140 142 and interlevel through vias 144 146 148 150 152 154 passing through dielectric layers 156 158 160 existence of the fuse 122 completing the circuit between interlevel vias 144 and 146 may be treated as a one and removal of the fuse i e blowing the fuse to open the circuit may be treated as a zero or vice versa the dielectric layers 130 156 158 and 160 may be any suitable dielectric material preferably a low k dielectric the low k dielectric may be for example silk u2122 dielectric resin from the dow chemical company any low k dielectric formed e g by chemical vapor deposition cvd fig2 b shows a cross section of the preferred embodiment fuse 122 of fig2 a through b b and adjacent wiring 162 in the same wiring layer 124 with like elements labeled identically the bottom surface 164 of fuses 122 formed according to the preferred embodiment of present invention have preferably rounded lower corners 166 such that the fuse 122 has other than a rectangular cross section further rounding may be such that the entire bottom surface 164 is rounded preferably however the corner arc has an effective radius that is equal to the depth of the fuse 122 and is at least 5 of the depth the rounded corners 166 of this example distribute the force that the.