| 摘要 |
PURPOSE:To protect the accuracy of transistor in a post process by forming a thermal oxide film for high accuracy after the formation of ordinary accuracy transistors and further forming a gate electrode for the high accuracy transistor. CONSTITUTION:After the formation of an insulation isolation band which isolates and divides first and second areas which form a transistor Tr on the surface of a semiconductor substrate, a gate oxide film 6 is formed on the substrate 1 in the first area while a gate electrode 3a and a lower part electrode 5a for a capacitor 5 are simultaneously formed by selectively etching a first polysilicon substance deposited on the substrate 1. Then, the substrate 1 is exposed in the second area and thermally oxidized, thereby forming a gate oxide film 11 for a second Tr and an oxide film 5b on the surface of the lower part electrode 5a simultaneously. Then, a second polysilicon substance 14 is deposited in such a fashion that it may cover the gate oxide film 11 and an oxide film 5b and it is selectively etched so as to form a gate electrode 5a and an upper part electrode 5c. |
