| 摘要 |
PURPOSE:To enable to form a deep diffusion layer by performing a short-time heat treatment by a method wherein a polycrystalline semiconductor region is formed in advance on the spot requiring a deep diffusion processing, and the characteristics of the polycrystalline semiconductor, having a larger impurity diffusion coefficient than a single crystal semiconductor, is utilized. CONSTITUTION:A buried diffusion region 2 is formed on a single crystal Si substrate 1, and a polycrystalline Si patterns 12A and 12B are formed on the region which comes in contact with the above region 2 and the region on the substrate which will be used as an isolation region. Then, when an epitaxial layer is formed on the whole surface, polycrystalline Si patterns 12A and 12B, and a single crystal layer 3 is formed on the other region. When the impurities, which are reverse conductive type to the single crystal layer 3 located around the polycrystalline layers 13A and 13B, are doped from the surface of the epitaxial layer, they are easily and uniformly diffused as far as to the single crystal substrate, and they are turned into a contact region 13B and an isolation region 13A respectively. |
