| 摘要 |
PURPOSE:To form thermal oxide films with no defects easily and effectively by a method wherein oxide films are formed by means of thermal oxidizing semiconductor wafer to form sulfur-added glass film on the oxide film for heat treatment. CONSTITUTION:A P-type Si wafer 1 is oxidized by means of burning hydrogen to form thermal oxide films 21, 22 on both sides. Then high concentration sulfuradded glass films 31, 32 are formed on the thermal oxide films 21, 22 on both sides by POCl3 diffusion. After removing the sulfur-added glass films 31, 32 and the thermal oxide films 21, 22 by etching process, the wafer 1 is oxidized in dried oxygen to form another thermal oxide film 4 to be a gate oxide film. A sulfur-added multicrystal silicon film is deposited and then this silicon film way be patterned by means of photoetching process to form a gate electrode 5 further forming an MOS capacitor. |
