| 摘要 |
PURPOSE:To achieve a simple and stable formation in spite of the large capacitance of a capacitor element by forming a groove at an insulation film isolating memory cell which are adjacent to each other and by expanding one electrode and the other electrode of the capacitor element to the inside of the groove. CONSTITUTION:The entire surface of an SiO2 film 17 is subjected to RIE for forming a side wall of the SiO2 film 17 at a word wire. At this time, overetching is performed so that a groove 12a is formed at an SiO2 film 12. N<+> regions 18a and 18b are formed, a polycrystalline Si film 24 is accumulated, and annealing is performed. Then, a resist 33 for the polycrystalline Si film 24 is subjected to patterning. Then, the polycrystalline Si films 24 and 32 are subjected to RIE using the resist 33 and the surface of the polycrystalline Si film 24 is oxidized after eliminating the resist 33, thus forming a dielectric film 28. Accumulation and patterning of a polycrystalline Si film 31 containing impurities are performed. Thus, the polycrystalline Si film 24 becomes one electrode, namely a memory node, which is connected to the n region 18b in a capacitor element and the polycrystalline Si film 31 becomes the other electrode of the capacitor element. |
