Semiconductor memory device
According to one embodiment, a semiconductor memory device includes a memory array and a peripheral circuit. The memory array has a plurality of memory cells, word lines, and bit lines, in which a first, second, and third blocks are set in the order along the bit line. The peripheral circuit has a transistor group. The transistor group includes a first transfer transistor belonging to the first block, a second transfer transistor belonging to the second block, and a third transfer transistor belonging to the third block. The first, second, and third transfer transistors share the other of a source and a drain of each. With regard to a direction in which either of the source and the drain is connected to the other in each of the first, second, and third transfer transistors, the directions of the adjacent transfer transistors are different from each other by 90° or 180°.
1. A semiconductor memory device comprising:
a memory array including:
a plurality of memory cells arranged on a substrate in a matrix state;
a plurality of word lines, each of the word lines commonly connected to the memory cells in a common row among the plurality of memory cells; and
a plurality of bit lines, each of the bit lines commonly connected to the memory cells in a common column among the plurality of memory cells,
a first block, a second block, and a third block being set in the order along the bit line and including the plurality of memory cells; and
a peripheral circuit including:
a transistor group formed on the substrate having:
a first transfer transistor, one of a source and a drain of the first transfer transistor being connected to a part of the word lines belonging to the first block;
a second transfer transistor, one of a source and a drain of the second transfer transistor being connected to a part of the word lines belonging to the second block; and
a third transfer transistor, one of a source and a drain of the third transfer transistor being connected to a part of the word lines belonging to the third block,
the first transfer transistor, the second transfer transistor, and the third transfer transistor sharing one other of the source and the drain, and
a direction connecting the source to the drain in each of the first transfer transistor, the second transfer transistor, and the third transfer transistor being different from each other by 90° or 180°.
2. The device according to claim 1 , wherein
the memory array further includes a fourth block subsequently to the first block, the second block, and the third block being set in the order along the bit line, and
the peripheral circuit further has a fourth transfer transistor, one of a source and a drain of the fourth transfer transistor being connected to a part of the word lines belonging to the fourth block,
the first transfer transistor, the second transfer transistor, the third transfer transistor, and the fourth transfer transistor sharing the other of the source and the drain, and
a direction connecting the source to the drain in each of the first transfer transistor, the second transfer transistor, the third transfer transistor, and the fourth transfer transistor being different from each other by 90° or 180°.
3. The device according to claim 2 , wherein
the direction of the first transfer transistor and the direction of the fourth transfer transistor are different from each other by 180°,
the first transfer transistor is arranged at a position closer to the first block than the fourth transfer transistor, and
the fourth transfer transistor is arranged at a position closer to the fourth block than the first transfer transistor.
4. The device according to claim 2 , wherein
the peripheral circuit has a plurality of the transistor groups,
arrangement of the first transfer transistor, the second transfer transistor, the third transfer transistor, and the fourth transfer transistor in each of the plurality of transistor groups being equal.
5. The device according to claim 3 , wherein
the peripheral circuit has a plurality of the transistor groups, and
arrangement of the first transfer transistor, the second transfer transistor, the third transfer transistor, and the fourth transfer transistor in each of the plurality of transistor groups being equal.
6. The device according to claim 4 , wherein
the plurality of transistor groups are arranged in the matrix state and the adjacent transistor groups are arranged with a shift in each of the row direction and the column direction by a half pitch.
7. The device according to claim 1 , wherein:
the peripheral circuit has
a first contact interconnect provided on either of the source and the drain, and
a second contact interconnect provided on the other of the source and the drain,
a longer direction in a cross section parallel to the substrate of the first contact interconnect being same as a longer direction in a cross section parallel to the substrate of the second contact interconnect.
8. The device according to claim 1 , wherein
the transistor groups are provided in a part of the peripheral circuit away from the memory array.
9. The device according to claim 1 , wherein
the first transfer transistor, the second transfer transistor, and the third transfer transistor drive for the first block, the second block, and the third block, respectively.
10. The device according to claim 2 , wherein
the first transfer transistor, the second transfer transistor, the third transfer transistor, and the fourth transfer transistor drive for the first block, the second block, the third block, and the fourth block, respectively.
11. The device according to claim 1 , wherein
the shape of a subscribed rectangle of the transistor group as viewed in a direction orthogonal to the substrate is a regular square.
12. The device according to claim 1 , wherein
a distance from the source to an end of the drain of the first transfer transistor, a distance from the source to an end of the drain of the second transfer transistor, and a distance from the source to an end of the drain of the third transfer transistor are equal.
13. The device according to claim 2 , wherein
a distance from the source to an end of the drain of the first transfer transistor, a distance from the source to an end of the drain of the second transfer transistor, a distance from the source to an end of the drain of the third transfer transistor, and a distance from the source to an end of the drain of the fourth transfer transistor are equal.
14. The device according to claim 1 , wherein
the peripheral circuit has a plurality of the transistor groups,
the plurality of transistor groups being arranged in a matrix state, and
the layout of the first transfer transistors, the second transfer transistors, and the third transfer transistors of the two transistor groups adjacent in the column direction being reversed with respect to the axis along the row direction.
15. The device according to claim 1 , wherein
the peripheral circuit has a first region and a second region closer to the memory array than the first region,
the first region includes the first transfer transistor, the second transfer transistor, and the third transfer transistor, and
the second region includes a fifth transfer transistor and a sixth transfer transistor adjacent to the fifth transfer transistor,
a direction connecting the source to the drain of the fifth transfer transistor and a direction connecting the source to the drain of the sixth transfer transistor being different from each other by 90°.
16. The device according to claim 2 , wherein
the peripheral circuit has a first region and a second region closer to the memory array than the first region,
the first region includes the first transfer transistor, the second transfer transistor, the third transfer transistor, and the forth transfer transistor, and
the second region includes a fifth transfer transistor and a sixth transfer transistor adjacent to the fifth transfer transistor,
a direction connecting the source to the drain of the fifth transfer transistor and a direction connecting the source to the drain of the sixth transfer transistor being different from each other by 90°.