| 摘要 |
PURPOSE:To prevent particles from attaching on a wafer surface on account of a silicon oxide film in a vapor growth equipment, and improve efficiency in a trench capacitor forming process, by forming an insulating film by oxidizing a polysilicon film deposited on a capacitance insulating film. CONSTITUTION:A trench is formed in an element forming region of a P-type silicon substrate 9, and a capacitance insulating film 2 is formed on the trench surface. A polysilicon film 3a is formed on the capacitance insulating film 2. A wafer is put in a thermal oxidation furnace, and an oxide film (insulating film 5a) is formed on the surface of the polysilicon film 3a. In order to fill the trench, a deposition film 4a like polysilicon is formed by a low pressure CVD method, and further the deposition film 4a is etched back, thereby filling the trench. After the formation of a trench capacitor is finished by patterning a multilayer film of the capacitance insulating film 2, the polysilicon film 3a, and the insulating film 5a, a gate oxide film 6 and a gate electrode 7 are formed, thereby obtaining a memory cell of a trench capacitor type. |
