Semiconductor memory device
View Patent ↗Parasitic capacitances formed between bit lines to which signals are to be read out of memory cells and a signal transmission line arranged above them are to be reduced. Second complementary global bit lines for transmitting data read out of memory cells MC via complementary bit lines are arranged above a memory cell array. Each second global bit line is so arranged that a triangle having as its vertexes the center of the section of one of the complementary bit lines, that of the section of the other and that of the section of the second global bit line arranged directly above these complementary bit lines be an isosceles triangle.
1. A semiconductor memory device comprising:
a pair of first data transmission lines; and
a second data transmission line,
wherein said pair of first data transmission lines are formed in a first layer on the main face of a semiconductor substrate and arranged to extend in a first direction of said main face,
wherein said second data transmission line is formed in a second layer which is different from said first layer and is arranged to extend in said first direction,
wherein said second data transmission line is so arranged as to substantially equalize a capacitance between one of said pair of first data transmission lines and said second data transmission line to a capacitance between the other of said pair of first data transmission lines and said second data transmission line, and
wherein said pair of first data transmission lines is positioned underneath said second data transmission line.
2. A semiconductor memory device according to claim 1 ,
wherein said second layer is positioned above said first layer.
3. A semiconductor memory device according to claim 1 , further comprising a plurality of memory cells,
wherein said pair of first data transmission lines is a pair of bit lines, and
wherein said plurality of memory cells are coupled to said pair of bit lines.
4. A semiconductor memory device according to claim 3 ,
wherein each of said plurality of memory cells is a static type memory cell.
5. A semiconductor memory device according to claim 1 , comprising a plurality of pairs of complementary first data transmission lines BL, /BL formed in said first layer on the main face of the semiconductor substrate and arranged to extend in said first direction of said main face in a series that includes, sequentially, BL, /BL followed by BL, /EL, and wherein said one and said other first data transmission lines are a pair of complementary first data transmission lines BL, /BL.
6. A semiconductor memory device according to claim 1 , wherein the first data transmission lines and the second data transmission line are arranged at vertexes of an isosceles triangle.