| 摘要 |
PURPOSE:To make it needless to effect a heat treatment at a high temperature for a long time and to enable the enhancement of a density of an integrated circuit by using a polysilicon layer as a ground connection region and a collector contact region. CONSTITUTION:An N<+> buried layer 2 is formed on a silicon substrate 1 selectively and a silicon dioxide film 8 is grown to become ground connection regions and collector regions selectively. An N type silicon layer 3 is grown and a polysilicon layer 5 is grown over the whole surface. An N type single crystal layer is exposed and a protective coating layer is formed. After that a U-shaped groove 4 is etched till it reaches the substrate 1 and polysilicon is grown by gas phase so far as it fills the U-shaped followed by polishing or etching to level it. After the ground connection region 10 is removed, boron ions are implanted and a resist film is removed. Subsequently the collector contact region 9 is exposed and phosphorus ions are implanted. Consequently a decrease of a temperature for the heat treatment in those regions becomes possible and impurities do not diffuse widely, thereby reduction of those regions becomes possible. |
