| 摘要 |
PURPOSE:To prevent the surface from being doped with needles impurities for improving reliability, by separating a doped oxide layer, which is a diffusion source, and a silicon oxide film, which is a mask material, with a polycrystalline film interposed between the two. CONSTITUTION:An oxide siliconfilm 2 and a polycrystalline silicon film 3 are piled up by turns on one conducting type semiconductor substrate 1. Next, the silicon film 2 is by turns etched to provide an opening part 4. Then, a doped silica film is applied to the surface including the opening part 4 for performing firing in order to form a doped oxide layer 5. Subsequently, heat treatment is performed to form an invese-conductive type diffusion layer 6. Then, after removing the doped oxide layer 5 by etching, and an axidation treatment is performed to form silicon oxide film 7. Next, the silicon oxide films 7 and 2 are removed by etching to grow the opposite conductivity type epitaxial layer 8 on the surface of the semiconductor substrate 1 including a difusion layer 6 so as to make the diffusion layer 6 a buried layer.
|
