Method of manufacturing capacitor structure

A method of manufacturing a capacitor structure, comprising:

• providing a substrate;
• forming a transistor on the substrate;
• forming a dielectric structure surrounding the transistor over the substrate;
• forming a third interconnect structure in the dielectric structure, wherein the third interconnect structure is in contact with doped regions of the transistor;
• forming a first doped silicon material layer on the dielectric structure;
• performing a surface flattening process on the first doped silicon material layer through a plasma treatment;
• forming an insulating material layer on the first doped silicon material layer after performing the surface flattening process;
• forming a second doped silicon material layer on the insulating material layer;
• patterning the first doped silicon material layer into a first electrode;
• patterning the insulating material layer into an insulating layer;
• patterning the second doped silicon material layer into a second electrode, to form a metal oxide semiconductor capacitor including the first electrode, the insulating layer and the second electrode;
• forming a first interconnect structure electrically connected to the first electrode;
• and
• forming a second interconnect structure electrically connected to the second electrode,
• wherein a temperature for forming the first doped silicon material layer ranges from 200° C. to 400° C., and a temperature for forming the second doped silicon material layer ranges from 200° C. to 400° C.