Patent ID: 7132725

Claim:
A semiconductor device characterized by comprising: a first semiconductor region ( 2 ) comprised of a semiconductor region of a first conductivity type and a second semiconductor region ( 3 ) formed at one major surface of said first semiconductor region ( 2 ) and comprised of a semiconductor region of a second conductivity type for forming a first semiconductor device ( 1 ) having a double RESURF structure and a second semiconductor device ( 21 ) having a single RESURF structure, wherein said first semiconductor device ( 1 ) includes: a third semiconductor region ( 5 , 43 ) formed at a predetermined surface region of said second semiconductor region ( 3 ) and comprised of a semiconductor region of the first conductivity type; and a fourth semiconductor region ( 9 , 42 ) formed near an interface between said first semiconductor region ( 2 ) and said second semiconductor region ( 3 ) in such a way as to face at least a part of said third semiconductor region ( 5 , 43 ) via said second semiconductor region, and comprised of a semiconductor region of the second conductivity type which has a higher impurity concentration than an impurity concentration of said second semiconductor region ( 3 ); and wherein said double RESURF structure of said first semiconductor device ( 1 ) is comprised of said first semiconductor region ( 2 ), said second semiconductor region ( 3 ), said third semiconductor region ( 5 , 43 ) and said fourth semiconductor region ( 9 ); and said single RESURF structure of said second semiconductor device ( 21 ) is comprised of said first semiconductor region ( 2 ) and said second semiconductor region ( 3 ).