Semiconductor device having a low resistivity trench capacitor

A trench capacitor, comprising:

• a first trench and a second trench disposed in a substrate;
• a first inner electrode disposed in a central portion of the first trench;
• a first capacitor dielectric layer disposed on the first inner electrode;
• a second inner electrode disposed in a central portion of the second trench;
• a second capacitor dielectric layer disposed on the second inner electrode;
• a first outer electrode and a second outer electrode disposed in the first trench and arranged symmetrically with respect to the first inner electrode;
• and
• a third outer electrode and a fourth outer electrode disposed in the second trench and arranged symmetrically with respect to the second inner electrode,
• wherein each of the first to fourth outer electrodes has a depth that is shallower than a depth of each of the first and second inner electrodes relative to a top surface of the substrate,
• wherein the first and second outer electrodes protrude above the top surface of the substrate, and each has a top surface located higher than a top surface of the first inner electrode, and
• wherein the second outer electrode disposed in the first trench is physically connected to the third outer electrode disposed in the second trench.

A trench capacitor, comprising:

• a first trench and a second trench disposed in a substrate;
• a first inner electrode disposed in a central portion of the first trench;
• a first capacitor dielectric layer disposed on the first inner electrode;
• a second inner electrode disposed in a central portion of the second trench;
• a second capacitor dielectric layer disposed on the second inner electrode;
• a first outer electrode and a second outer electrode disposed in the first trench and arranged symmetrically with respect to the first inner electrode;
• and
• a third outer electrode and a fourth outer electrode disposed in the second trench and arranged symmetrically with respect to the second inner electrode,
• wherein each of the first to fourth outer electrodes has a depth that is shallower than a depth of each of the first and second inner electrodes relative to a top surface of the substrate,
• wherein the second outer electrode disposed in the first trench is physically connected to the third outer electrode disposed in the second trench, and
• wherein the second and third outer electrodes are connected to each other through a connection portion disposed on and extending along the top surface of the substrate.