Method of manufacturing through-silicon-via and through-silicon-via structure

A method for fabricating a through-silicon-via, at least comprising:

• forming a first annular trench in a silicon substrate;
• forming a first conductive layer, a capacitor dielectric layer, and a second conductive layer in the first annular trench;
• forming an opening in the silicon substrate surrounded by the first annular trench;
• disposing an insulating layer on an inner surface of the opening;
• filling a conductive material into the opening;
• performing a planarization process on a back of the silicon substrate for removing a portion of the silicon substrate, which simultaneously removes the insulating layer from a bottom of the opening to form a conductive through-via and removes the first conductive layer and the capacitor dielectric layer from a bottom of the first annular trench;
• removing the silicon substrate, the first conductive layer, and the capacitor dielectric layer between the insulating layer and the second conductive layer to form a second annular trench;
• filling a low-k material into the second annular trench;
• and
• forming a bump to be in contact with the conductive through-via on the bottom of the opening.