| 摘要 |
PURPOSE: To provide a method for manufacturing a stack-type capacitor device which has a large effective surface area for its electrode. CONSTITUTION: On the surface of a semiconductor substrate 30, a field oxide region 38, a gate layer 11 of a dielectric, and a 1st polysilicon layer 12 are provided to form a source/drain structure 22, and then a 1st oxide layer is formed. A capacitor is etched to have an opening for a desired source/drain structure. Then a 2nd silicon layer 32, which has been doped to a high density is stuck on a device and the field oxide region, and a 3rd polysilicon layer 34 which is not doped is stuck on the opening. The layers 32 and 34 are patterned anisotropically and left on a flat capacitor region, the part of the layer 12 of a gate structure, and a region 28. Part of the layer 32 is removed, an undercut of the layer 34 is formed on a part of the layer 12 of the gate structure and the region 28, and a storage node electrode of the bottom part of a desired capacitor is formed. Then the rest of the electrode is doped. |
