| 摘要 |
PURPOSE:To facilitate easily the formation of a connection part with excellent controllability, by a method wherein, after only a region, in which the connection part of a side wall surface of a groove is formed, is coated with an oxidation-resistant film, and the inner surface of other groove is selectively oxidized, the oxidation- resistant film is eliminated, and the surface of the connection part is exposed. CONSTITUTION:A shallow groove 16 is formed, by selectively eliminating a PSG film 15, a poly-crystalline silicon film 14, an SiO2 film 2 and a silicon substrate 1, in the manner in which a part of an element isolation region formed on a P-type silicon substrate 1 is penetrated. By oxidizing the inner surface of the groove 16, a thin SiO2 film 17 is grown, and further a silicon nitride film 18 is deposited. By anisotropic etching, the film 18 is eliminated and left only on the side wall of the shallow groove. Then, a deep groove is formed, by anisotropically etching the SiO2 film 16 and the lower substrate. By thermally oxidizing the side wall of the deep groove, an SiO2 film 3 is formed on the inner wall, but the side surface 9' of a connection part coated with a film 18 is not oxidized at all. By eliminating the film 18, and further eliminating the thin film 17 on the region 9' surface, the silicon surface on the side wall is exposed. By forming a polycrystalline silicon electrode 4 so as to contain said surface, connection is completed. |
