The semiconductor devices may include a semiconductor substrate, and a guard ring and a crack sensing circuit on the semiconductor substrate. The semiconductor substrate may include a main chip region that is defined by the guard ring and includes the crack sensing circuit, a central portion of the main chip region surrounded by the crack sensing circuit, and a chamfer region that is in a corner portion of the main chip region and is defined by the guard ring and the crack sensing circuit. The semiconductor devices may also include at least one gate structure on the semiconductor substrate in the main chip region, a plurality of metal pattern structures on the at least one gate structure in the chamfer region, and an insulating layer on the plurality of metal pattern structures. The plurality of metal pattern structures may extend in parallel to one another and may have different lengths.