Wiring structures having intersecting metal patterns

A wiring structure includes first to third metal patterns on a substrate. The first metal pattern extends in a second direction and has a first width in a third direction. The second metal pattern extends in the third direction to cross the first metal pattern and have a second width in the second direction. The third metal pattern is connected to the first and second metal patterns at an area where the first and second metal patterns cross each other, and has a substantially rectangular shape with concave portions in each quadrant. The third metal pattern has a third width defined as a minimum distance between opposite ones of the concave portions in a fourth direction having an acute angle to the second and third directions, which is less or equal to than a smaller of the first and second widths.