| 摘要 |
PURPOSE:To prevent a thin natural oxide film from being grown in a reduced pressure CVD furnace by changing the natural oxide film formed on a surface of a polycrystalline silicon layer in which a high concentration impurity is diffused to a silicon nitride film by a rapid nitriding process. CONSTITUTION:An oxide film 12 is formed by oxidization of a semiconductor substrate 11 surface, and a polycrystalline silicon layer 13 is deposited on the resulting oxide film 12. Then, a natural oxide film 18 is changed to a nitride film 19 by rapid nitrization. Further, a silicon nitride film 15 is deposited on the nitride film 19 by a reduced pressure CVD process, and a surface of the silicon nitride film 15 is oxidized to form an oxide film 16. Further, a second layer polycrystalline silicon layer 17 is deposited on the oxide film 16, into which impurity P is doped by a necessary amount. As a result, a stable thickness and large capacity thin insulating film can be formed on the polycrystalline silicon layer in which high concentration impurity has been doped. |
