| 摘要 |
PURPOSE:To enable to efficiently form the contact holes, each having a gently formed sectional configuration, without inflicting any damage on the substrate by a method wherein step forming films are coated on the contact hole forming regions, insulating layers are coated on the whole surface of the substrate covering the step forming films, then after an isotropic etching is performed on the insulating layers until the side surfaces of the step forming films are made to expose, the step forming films are removed. CONSTITUTION:An SiO2 layer 12 is formed on an Si substrate 11 by performing a heat treatment using wet oxygen. Then, polycrystalline silicon layers 13 are coated as step forming layers 13 by a CVD method, a patterning is performed by an anisotropic dry etching method and the step forming layers 13 are left on the contact hole forming regions only to form steps on the substrate 11. PSG layers 14 are coated on the whole surface of the substrate as insulating layers 14 covering the steps by a CVD method. An isotropic etching is performed on the layers 13, whereby the layers 13 are lifted-off together with the layers 14 coated on the layers 13. Then, the layers 12 on the contact holes are removed using an HF. According to such a process, the contact holes respectively have a good and gentle sectional configuration and no damage is inflicted on the substrate. |
