A fusible structure includes a metal line with different portions having different thicknesses. Thinner portions of the metal line are designed to be destructively altered at lower voltages while thicker portions of the metal line are designed to be destructively altered at lower voltages. Furthermore, one or more dummy structures are disposed proximal to the thinner portions of the metal line. In some embodiments, dummy structures are placed with sufficient proximity so as to protect against metal sputtering when metal line is destructively altered.