| 摘要 |
PURPOSE:To obtain a semiconductor memory device whose capacity is larger than 64M bits and which is able to carry out a sense operation stably by a method wherein each bit line is formed into a shielded structure, and a shielded electrode is kept at the same potential with the bit line. CONSTITUTION:The memory cell of a semiconductor memory device is composed of a transfer MOS transistor 11 and a stacked type capacitor 12. A polysilicon shield electrode and a bit line 24 are buried in a trench 21 provided adjacent to the memory cell, and the bit line 24 is directly connected to the drain region 14 of the MOS transistor 11 with a diffusion layer. That is, the bit line 24 is filled into the trench 21 of a semiconductor substrate, and a shield electrode is provided to the base and the side wall of the trench 21 to shield the bit line 24. By this setup, coupling capacitance between the bit lines 24 and the bit line 24 and a substrate can be lessened. |
