| 摘要 |
PURPOSE:To inhibit leakage currents along the end section of an end section region in an isolation region and the fluctuation of threshold voltage, to increase the surface area of capacitance and to miniaturize a storage cell by forming a capacitance region including the bottom or side surface of a trench shaped to a substrate inside the isolation region while forming a transistor inside the capacitance region. CONSTITUTION:An isolation region 1 surrounds the periphery of a cell, and a capacitance 2 is constituted of an insulating thin-film shaped onto the wall and bottom of a trench and two electrodes of an impurity diffusion layer 7 and poly Si 8. Information from a data line is transmitted over a diffusion layer 7 through a connecting hole 4, and stored in the diffusion layer 7 in the capacitance 2 by opening and closing a PET 3. The surface area of the capacitance 2 is increased by utilizing the wall and the bottom, and one part of the FET 3 is shaped into the trench and an occupying area is reduced. The flow of currents between source-drain in the FET 3 is not made parallel with the end section of the isolation region 1. Consequently, the generation of, leakage currents and the fluctuation of threshold voltage are inhibited. According to the constitution, a small-sized one-transistor storage device is acquired. |
