| 摘要 |
PROBLEM TO BE SOLVED: To enable formation of a capacitor of adequate capacitance without making a step-difference between a memory cell and a peripheral circuit so large that photolithography becomes difficult. SOLUTION: A capacitor structure is formed on a main surface 18a of a substrate 18 comprising an interlayer insulating film 10, a plug 14 and a silicon nitride film 16. The capacitor structure comprises a storage electrode 20, a capacitor insulating film 22 and a cell plate electrode 24. The lower surface of a bottom part 20b of the storage electrode 20 is in contact with the surface of a plug, and the wall part 20a is arranged perpendicularly to the main surface. The wall part constitutes a cylindrical surface, and its lower end is connected with the bottom part. The capacitor insulating film 22 and the cell plate electrode 24 are formed on the storage electrode 20. By making the area of the aperture of a cell contact hole large compared with the occupying area of a capacitor pattern restricted by the limit of resolution of photolithography, the area of an aperture part 26 is made larger than that in the normal case. |
