Patent ID: 6555884
Filing Date: 2003-04-29
Classification: H01L

Abstract:
A semiconductor device comprising:a circuit region including transistors formed on a semiconductor substrate; a first guard ring of an ion diffused region formed around said circuit region; a second guard ring of a high concentration ion diffused region formed around said first guard ring with a prescribed gap therebetween; a first metal film electrically connected to the first guard ring via a contact hole formed through an insulating film; a second metal film electrically connected to the second guard ring via another contact hole formed through said insulating film; wherein said first metal film is supplied with a first potential; wherein said second metal film is supplied with said first potential; each of said transistors having a drain region and a source region; and wherein said first and second guard rings have higher concentrations of impurities than said drain region and said source region of said transistors.