| 摘要 |
PURPOSE:To enlarge the surface area of a lower electrode, by forming an aperture window whose width belongs to an unsaturated region in microloading characteristics, in a conducting layer mask region in a pattern for working the conducting layer as the lower electrode, before the conducting layer is etched. CONSTITUTION:A pattern 10 has mask parts 11 for working the lower electrode of a capacitor of a conducting layer 9, and is formed so as to correspond with each of the memory cell on a wafer. Two small aperture windows are formed in each of the mask parts 11, whose width is set to be a dimension belonging to an unsaturated region. The conducting layer 9 is etched by an RIE method using the pattern 10 as a mask, and a lower electrode 14 is worked. Since the etching rate of the aperture windows 12, 13 is small, the etching is not ended when the working of the lower electrode 14 is finished, and recessed parts 15, 16 whose depth is (b) are formed in the upper surface of the lower electrode 14. Hence the surface of the lower electrode 14 turns to an uneven form, and the surface area of the electrode is increased. |
