| 摘要 |
PURPOSE:To enable formation of different capacitors in the same substrate by enhancing the integrity of the capacitors by forming a groove on the substrate when forming MOS capacitors and burying capacitor electrodes through capacitor insulating film therein. CONSTITUTION:A thick field SiO2 film 12 is formed at the periphery of a P type substrate 11, a groove 13 is formed by photoetching process at one side of the substrate 11 surrounded by the film 12, and an SiO2 film 14 becoming an insulating film for the capacitor later is coated on the substrate 11 including the side walls and the bottom surface. Then, polycrystalline Si film 15 including N type impurity are accumulated on the entire surface, and are filled also in the groove 13. The film 15 is etched to expose the film 14 formed thereunder, and capacitor electrode 16 is retained through a capacitor insulating film 17 made of the film 14 in the groove 13. Thereafter, an SiO2 film 18 is covered on the surface of the substrate, a window is opened thereat, an N<+> type region 22 becoming digit line is diffusion formed, and a gate electrode 20 is formed on the film 18 corresponding to the electrode 16.
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