Semiconductor device and a method of increasing a resistance value of an electric fuse

A semiconductor device, comprising:

• a semiconductor substrate;
• a first interlayer dielectric formed over the semiconductor substrate, the first interlayer dielectric having a trench;
• an electric fuse comprising:
• a main wiring in the trench;
• and
• a barrier film covering a lower face of the main wiring and side faces of the main wiring;
• a second interlayer dielectric formed on the first interlayer dielectric such that the second interlayer dielectric directly contacts with the main wiring;
• and
• a first wiring overlapping with the main wiring in a plan view,
• wherein the main wiring comprises:
• a first portion;
• and
• a second portion connected with the first portion, the second portion having a width greater than a width of the first portion;
• wherein the first portion and the second portion are formed in the trench,
• wherein a linear expansion coefficient of the electric fuse is larger than a linear expansion coefficient of the first interlayer dielectric and the second interlayer dielectric, and
• wherein a melting point of the main wiring is lower than a melting point of the first interlayer dielectric and the second interlayer dielectric.