Patent ID: 7880262

Claim:
A semiconductor device having an output element formation region, an other element formation region, and an active barrier region arranged between said output element formation region and said other element formation region, comprising: a semiconductor substrate having a main surface, a first region of a first conductivity type formed in said semiconductor substrate in said output element formation region, said other element formation region, and said active barrier region; a second region of a second conductivity type formed in said semiconductor substrate in said output element formation region, said other element formation region, and said active barrier region so as to form a pn junction with said first region and to be positioned on the main surface side of said semiconductor substrate rather than said first region; an active barrier structure having a third region of the first conductivity type and a fourth region of the second conductivity type, each of which is in contact with said first region and which are ohmic-connected to each other to attain a floating potential, in said active barrier region; and a trench isolation structure having a trench formed at least one of between said active barrier region and said output element formation region and between said active barrier region and said other element formation region and formed to extend from the main surface of said semiconductor substrate through said second region and then reach said first region.