Patent ID: 6867462
Filing Date: 2005-03-15
Classification: H01L

Abstract:
1. A semiconductor device comprising: an insulating layer; a semiconductor layer provided on the insulating layer; and an isolation region for dividing the semiconductor layer into a plurality of active regions for forming semiconductor elements therein, wherein each of the isolation regions includes: a trench penetrating the semiconductor layer to reach the insulating layer; side insulating films covering respective sides of the trench; and a polycrystalline semiconductor region interposed between the side insulating films and having a pn junction extending along the depth direction of the trench, wherein the polycrystalline semiconductor region includes: polycrystalline semiconductor layers of a first conductivity type covering respective sides of the side insulating films; and a polycrystalline semiconductor layer of a second conductivity type interposed between the polycrystalline semiconductor layers of the first conductivity type, and pn junctions extending along the depth direction of the trench are formed between each of the polycrystalline semiconductor layers of the first conductivity type and the polycrystalline semiconductor layer of the second conductivity type.