Trench capacitor of a DRAM and fabricating method thereof

A method of fabricating trench capacitors, comprising the steps of:

• providing a substrate having at least an isolation structure formed thereon;
• forming a first trench and a second trench in the substrate beside the isolation structure and removing a portion of the isolation structure between the first trench and the second trench to form an opening;
• forming a first lower electrode and a second lower electrode in the substrate around the first trench and the second trench respectively;
• forming a first capacitor dielectric layer and a second capacitor dielectric layer on the respective surfaces of the first trench and the second trench;
• and
• filling the first trench, the second trench and the opening with a conductive material to form a first upper electrode, a second upper electrode and a conductive layer, wherein the first upper electrode and the second upper electrode are electrically connected through the conductive layer.