Semiconductor storage device

Abstract

Abstract PURPOSE:To inhibit leakage currents flowing along the end of an isolation region and the fluctuation of threshold voltage, to increase the surface area of a capacitance, and to obtain a small-sized storage cell by forming the capacitance including the bottom and wall of a trench shaped to a substrate inside the isolation region while a transistor is formed into the trench on the inside of the capacitance. CONSTITUTION:A capacitance 2 on the inside of all isolation region 1 is constituted of an insulating thin-film shaped on the wall and bottom of a trench formed to a substrate and two electrodes of an impurity diffusion layer 7 and poly Si 8. Information from a data line is transmitted over an impurity diffusion layer 7 in a switching transistor 3 through a connecting hole 4, and stored in the impurity layer 7 in the capacitance 2 by opening and closing a FET 3. The surface area of the capacitance is increased by utilizing the bottom and wall of the trench. The flow of currents between source-drain in the FET is not made parallel with the end section of the isolation region 1, thus inhibiting the generation of leakage currents and the fluctuation of threshold voltage. According to the constitution, a small-sized one-transistor storage cell is acquired.

Inventors

• 👤 Shinichi Sato
• 👤 真一 佐藤

Bibliographic Details