MANUFACTURE OF CAPACITOR

PROBLEM TO BE SOLVED: To provide the manufacturing method of a capacitor, which increases the capacity of the capacitor without reducing reliability of the capacitor. SOLUTION: This manufacturing method of this capacitor has a step of form an interconnection line 26 over a substrate 24, a step of depositing a first dielectric layer 28 on the line 26, a step of etching a through hole (increases toward the direction of the substrate and has a width of a tapered form) in the layer 28, a step of filling a conductive metal layer in the through hole for forming a metallic plug 32 in the layer 28, a step of etching a trench 30 in the layer 28 on the periphery of the upper part of the plug 32, a step of deposing a second dielectric layer 38 on a lower electric layer 36, in close proximity to the plug 32 and a step to deposit an upper electrode layer 40 on the layer 28.