| 摘要 |
PURPOSE:To lengthen the distance of a drain and a diffusion layer for capacitance substantially, and to reduce leakage currents even on fining by forming an insulating film to at least one part of the lower section of the drain between a capacitance section formed, surrounding a transistor and the drain. CONSTITUTION:A capacitance section as one element of a memory cell is shaped, surrounding a transistor, and an insulating film 48 is formed to at least one part of the lower section of a drain 46 between the capacitance section and the drain 46 in the transistor. The capacitance section such as a trench type capacitance section is formed so as to surround the transistor such as an MOS transistor constituted of a source 45, a gate 43 and the drain 46 shaped to a substrate such as a P-type Si substrate 31. The insulating layer 48 such as an oxide layer 48 is formed between an N-type diffusion layer 35 as one electrode of the trench type capacitance and the N-type diffusion layer 46 as the drain in the MOS transistor. The layer 48 is shaped by implanting oxygen to an silicon base body or formed by oxidizing silicon, and the oxide layer 48 is used as an insulator. |
