| 摘要 |
PURPOSE:To stably open a contact hole by forming another polycrystalline layer on the first polycrystalline layer simultaneously upon formation of the second polycrystalline layer in such a manner as to equalize the thickness of an insulating film formed on the surface. CONSTITUTION:A thermally oxidized film is formed on a silicon single crystalline substrate 1, the first polycrystalline silicon layer 3 is selectively formed, and an oxidized film is covered. Then, the first polycrystalline layer 3 is partly exposed by photoetching, and a polycrystalline layer 13 is formed simultaneously upon formation of the second polycrystalline layer 6. Subsequently, a thermally oxidized film is formed on the surface of the layer 13, and an oxidized film layer 9 containing phosphorus is formed. A contact hole is then opened by using a photoresist 10. Accordingly, only the thickness of the oxidized film is approximately equalized by forming the layer 13, and the controllability for removing by etching can be increased. Further, the difference of the size of the contact hole can be reduced. |
