Patent ID: 8704328

Claim:
A high-voltage integrated circuit device, which is a high-voltage semiconductor integrated circuit device that drives a high-potential-side power transistor out of two serially connected power transistors, the high-voltage semiconductor integrated circuit device comprising: a high-potential region of second conductivity type that is formed on a surface layer of a semiconductor substrate of first conductivity type; a breakdown voltage region of second conductivity type that is formed on the surface layer of the semiconductor substrate, in contact with the high-potential region and along an outer circumference of the high-potential region, and that has an impurity concentration lower than that of the high-potential region; a ground potential region of first conductivity type that is formed on the surface layer of the semiconductor substrate, in contact with the breakdown voltage region and along an outer circumference of the breakdown voltage region, and that is applied with a ground potential; a low-potential region of second conductivity type that is formed outside the ground potential region on the surface layer of the semiconductor substrate; an intermediate-potential region of first conductivity type that is formed within the high-potential region so as to be joined to and separated from the high-potential region; a first contact region of second conductivity type that is formed along an end part of the breakdown voltage region that is on the high-potential region side; a second contact region of first conductivity type that is formed on a surface layer of the ground potential region so as to face the first contact region; a first pickup electrode that is in contact with the first contact region; and a second pickup electrode that is in contact with the second contact region, wherein the intermediate-potential region is a region to which is applied an intermediate potential between a high-potential-side potential and a ground potential of a high-voltage power supply, which is a main circuit power supply of the two serially connected power transistors, the low-potential region is a region to which is applied a high-potential-side potential of a first low-voltage power supply based on the ground potential, the high-potential region is a region to which is applied a high-potential-side potential of a second low-voltage power supply based on the intermediate potential, a high-voltage junction terminating region, which is configured by the breakdown voltage region, the ground potential region, the first contact region and the second contact region, is formed, and in a section of the high-voltage junction terminating region, whose distance to the intermediate-potential region is shorter than those of other sections, a resistance of a current path between the first pickup electrode and the second pickup electrode is higher than those of the other sections.