Semiconductor device and manufacturing method thereof

A semiconductor device, comprising:

• a first wire on an insulating surface;
• a second wire over the first wire and extending in a same direction as the first wire;
• a third wire over the second wire, the third wire electrically connected to the first wire and the second wire and crossing the first wire and the second wire;
• and
• an insulating film covering the first wire, the second wire, and the third wire,
• wherein the first wire is wider than the second wire at a crossing portion of the second wire and the third wire, and in a vicinity of the crossing portion.

A display device, comprising:

• a first scan line on an insulating surface, the first scan line comprising a first conductive layer and a second conductive layer over the first conductive layer;
• a second scan line on the insulating surface, the second scan line comprising a third conductive layer and a fourth conductive layer over the third conductive layer;
• an insulating layer over the first scan line and the second scan line;
• and
• a signal line over the insulating layer and intersecting with the first scan line and the second scan line with the insulating layer interposed therebetween,
• wherein the first conductive layer is wider than the second conductive layer at a first crossing portion of the first scan line and the signal line, and in a vicinity of the first crossing portion, and
• wherein the third conductive layer is wider than the fourth conductive layer at a second crossing portion of the second scan line and the signal line, and in a vicinity of the second crossing portion.