Semiconductor device including a separation region formed around a first circuit region

A semiconductor device comprising:

• a substrate of a first conductivity type;
• a first circuit region formed in the substrate and formed with a first circuit of which a power supply potential is a first voltage;
• a separation region that surrounds the first circuit region;
• a second circuit region formed in the substrate, the second circuit region being positioned outside the separation region in a planar view and formed with a second circuit of which a power supply potential is a second voltage lower than the first voltage;
• and
• a first conductivity type region formed in the substrate around a periphery of the separation region,
• wherein the separation region includes:
• a second conductivity type layer formed in the substrate;
• a first high concentration second conductivity type region formed in the second conductivity type layer;
• a second high concentration second conductivity type region formed in the second conductivity type layer and away from the first high concentration second conductivity type region, a bottom portion of the first conductivity type region being formed beneath the second high concentration second conductivity type region such that the second conductivity type layer is formed between the bottom portion of the first conductivity type region and the second high concentration second conductivity type region;
• an element isolation film formed in the substrate, the element isolation film being positioned between the first high concentration second conductivity type region and the second high concentration second conductivity type region and away from the second high concentration second conductivity type region;
• a first insulation film formed over a region of the substrate, the region being positioned between the second high concentration second conductivity type region and the element isolation film;
• a first conductive film formed over the first insulation film;
• a first contact coupled to the first high concentration second conductivity type region;
• a second contact coupled to the second high concentration second conductivity type region;
• and
• a third contact coupled to the first conductive film, and
• wherein the first contact, the second contact and the third contact are separated from each other.