Patent ID: 7071527

Claim:
A semiconductor element comprising: a first semiconductor region ( 2 ) of a first conductive type; a second semiconductor region ( 3 ) of a second conductive type which is formed on said first semiconductor region ( 2 ); a third semiconductor region ( 6 ) of a first conductive type which is formed in a predetermined surface area of said second semiconductor region ( 3 ); a fourth semiconductor region ( 7 ) of a first conductive type which is formed in a surface area of said third semiconductor region ( 6 ) and has a higher impurity concentration than said third semiconductor region ( 6 ) has; and a fifth semiconductor region ( 8 ) formed in a surface area of said second semiconductor region ( 3 ) so as to surround said third semiconductor region ( 6 ); said third semiconductor region ( 6 ) having a central portion ( 6 a ) surrounding said fourth semiconductor region, and a peripheral portion ( 6 b ) surrounding said central portion ( 6 a ); said central portion ( 6 a ) being formed to have a depth from a surface of said second semiconductor region ( 3 ) deeper than that of said peripheral portion ( 6 b ); said second semiconductor region ( 3 ) arranged right under said central portion ( 6 a ) having a smaller amount of electric charges than an amount of electric charges of said second semiconductor region ( 3 ) arranged generally under said peripheral portion ( 6 b ), and said second semiconductor region ( 3 ) arranged generally under said central portion ( 6 a ) having a thickness thinner than that of said second semiconductor region ( 3 ) arranged generally under said peripheral portion ( 6 b ); and an isolation region ( 4 ) of a first conductive type which is formed at an outer edge of said second semiconductor region ( 3 ); and a sixth semiconductor region ( 5 ) formed in a surface area of said second semiconductor region ( 3 ) so as to contact said isolation region ( 4 ), wherein said second semiconductor region ( 3 ) which is present generally under said sixth semiconductor region ( 5 ) has a same thickness as that of said second semiconductor region ( 3 ) which is present generally under said peripheral portion ( 6 b ).