| 摘要 |
PURPOSE:To obtain an I<2>L without the generation of the failure of collector-base withstand voltage by a method wherein a semiconductor layer containing an impurity of conductivity type different from that of a base region is placed on said region, and then a collector region is formed by making the thickness of an insulation layer covering the semiconductor layer larger as it becomes closer to the base region, when the collector region is formed in the base region by diffusing the impurity by heat treatment. CONSTITUTION:An N<-> type buried region 2 is diffusion-formed in the surface layer part of a P type Si substrate 1, an N type layer 3 is epitaxially grown over the entire surfaces including said region, and an N<+> type emitter region 4 reaching the region 2 is formed thereat. Next, thick field oxide films 5 are formed on both sides of the surface of the region 4 and on the other end of the layer 3, a P type injector region 6 and a P type base region 7 are diffusion-formed in the layer 3 other than the region 4, and the clearance therebetween is covered with an oxide film 9. Thereafter, a polycrystalline Si layer 8 containing As is provided on the region 7 and surrounded by an oxide film 11, and an N<+> type collector region is formed in the region 7 by diffusing the impurity in the layer 8 by heat treatment. At this time, the thickness of the film 11 is kept formed more thickly as it becomes closer to the region 7. |
