| 摘要 |
PROBLEM TO BE SOLVED: To provide a trench capacitor which exhibits reduced leakage of charge and increased capacitance. SOLUTION: A trench is formed in a substrate 301. The lower part of the trench is provided with a semiconductor material 320. A dielectric collar part is formed in the upper part of the trench above the semiconductor material. The semiconductor material is removed from the bottom of the trench. A node dielectric layer 364 backed by the collar and the sides of the trench is formed on the bottom of the trench. The trench is filled with a doped semiconductor material serving as an electrode for a trench capacitor 360. In this case, the diameter of the bottom of the trench is set at least almost equal to that of its upper part to be advantageous. |
