Patent ID: 6867437
Filing Date: 2005-03-15
Classification: H01L

Abstract:
1. A semiconductor device including a diode structure in which main current flows between first and second main surfaces sandwiching an intrinsic or a first conductivity type semiconductor substrate, comprising: a first impurity region of a first conductivity type formed at said first main surface of said semiconductor substrate and having a higher impurity concentration than that of said semiconductor substrate; and a second impurity region of a second conductivity type formed at said second main surface of said semiconductor substrate; wherein said semiconductor substrate has trenches extending parallel to each other formed at said first main surface to sandwich said first impurity region; said device further comprising: a third impurity region of the second conductivity type formed on a sidewall of the trench at said first main surface to be adjacent to said first impurity region; a forth impurity region of the first conductivity type having lower concentration than said first impurity region, formed immediately below said third impurity regions to be in contact with the sidewall of said trench and the region of said semiconductor substrate and to be adjacent to said first impurity region; a control electrode layer formed in said trench to oppose to said region of said semiconductor substrate and said third and fourth impurity regions with an insulating film interposed; a first electrode layer formed on said first main surface of said semiconductor substrate and electrically connected to said first and third impurity regions; and a second electrode layer formed at said second main surface of said semiconductor substrate and electrically connected to said second impurity region.