Patent ID: 8791576

Claim:
A semiconductor device comprising: a rectangular semiconductor substrate which includes a semiconductor circuit region and four corners; a first insulating film which is planarized and which includes silicon, oxygen and carbon formed above the rectangular semiconductor substrate; a first conductive layer, which includes a first tantalum based film and a first copper film, formed in the first insulating film; a second insulating film which includes silicon and nitrogen, formed above the first insulating film and the first conductive layer; a third insulating film which includes silicon and oxygen, formed above the second insulating film; a fourth insulating film which includes silicon and nitrogen, formed above the third insulating film; a fifth insulating film which is planarized, formed above the fourth insulating film, and which includes silicon and oxygen; and a second conductive layer formed in the fourth insulating film and the fifth insulating film, a plurality of guard rings surrounding the semiconductor circuit region; wherein: the guard rings comprise a groove-shaped via formed in the second insulating film and the third insulating film; the groove-shaped via and the second conductive layer include a second tantalum based film and a second copper film; the first conductive layer, the groove-shaped via and the second conductive layer include patterns bent twice each time at an angle of larger than 90 degree at each of the four corners; and the patterns are bent totally at 90 degree at each of the four corners of the rectangular semiconductor substrate.