Patent ID: 7271449
Filing Date: 2007-09-18
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a first well region of the first conductivity type which is formed to extend from a surface of the semiconductor substrate toward an inside thereof; a pair of second well regions as of a second conductivity type which are formed to extend from the surface of the semiconductor substrate toward the inside thereof in such a manner as to sandwich the first well region there between; and a third well region of the second conductivity type which is formed under each of the first well region and the pair of second well regions in the semiconductor substrate, wherein the third well region intersects the first well region and the pair of second well regions at right angles with respect to a direction along which each of the first well region and the pair of second well regions extends. the third well region electrically connects the pair of second well regions to each other and the first well region is partially connected to a region of the semiconductor substrate in which he third well region is not formed.