Patent ID: 8159001

Claim:
A semiconductor device comprising: a substrate that includes impurities of p-type, the substrate comprising: an n-well within the substrate that includes impurities of n-type; a p-well within the substrate that includes impurities of p-type, wherein the p-well is horizontally spaced apart from the n-well by a graded junction space within the substrate, the graded junction space between the p-well and the n-well of a width between 0.6 micrometers and 20 micrometers and doped with a concentration of p-type impurities at least two orders of magnitude less than a concentration of impurities of p-type in the p-well and a concentration of impurities of n-type in the n-well; a first field oxide (FOX) layer in the substrate between the n-well and the p-well; a first tap to the n-well that is surrounded by a first region implanted with impurities of n-type; and a second tap to the p-well that is surrounded by a second region implanted with impurities of p-type.