Patent ID: 7745905

Claim:
A semiconductor device, comprising: a first insulator layer; a first trench formed in the first insulator layer; an electric fuse which includes a first barrier metal formed on a bottom surface of the first trench and a side wall of the first trench, and a copper metal formed on the first barrier metal and filling in the first trench, wherein a resistance of the electric fuse can be controlled by applying electrical current to the electric fuse; a second insulator layer formed on the first insulator layer and the electric fuse; and a third insulator layer formed on the second insulator layer, wherein a linear expansion coefficient of the copper metal is higher than that of the first and third insulator layers, wherein the copper metal has a lower melting point than melting points of each of the first and third insulator layers, and wherein a dielectric relative constant of the first and third insulator layer is 3 or less.