| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the trench capacitor of an SOI board must conventionally extend a trench opening through the insulation body layer of the SOI board and is isolated from a board surface by the isolation body film of a board structure not to be easily contacted. SOLUTION: The trench capacitor 47 formed on the SOI board extends into a semiconductor base board 1 through an upward silicon layer 5 and the isolation layer. The outside electrode of the trench capacitor includes the part of the semiconductor base board 1 making the boundary of a trench forming the trench capacitor. The outside electrode is formed immediately near to the trench capacitor, and connected to a contact structure 45 extending through the isolation layer. The method for simultaneously preparing the trench capacitor 47 and the contact structure 45 includes a step for forming two trench openings 51, 53, a step for forming a dielectric liner on one of the trench openings 51, 53, and a step for filling the trench openings respectively with a semiconductor substance. |
