Dynamic RAM-and semiconductor device
View Patent ↗A semiconductor memory includes a plurality of first regions arranged along a first direction, each of which corresponds to a memory array including a plurality of word lines, bit lines and memory cells. A plurality of second regions are provided each of which is arranged alternately with respect to each of the first regions, and each including sense amplifiers connected to said bit lines to form an open line type semiconductor memory. A third region is also provided that is a region not sandwiched by the second regions, wherein the third region includes a plurality of dummy bit lines.
1. A semiconductor memory comprising:
a plurality of first regions arranged along a first direction, each of which corresponds to a memory array including a plurality of word lines, a plurality of bit lines and a plurality of memory cells; and
a plurality of second regions, each of which is arranged alternately with respect to each of said first regions arranged along said first direction and each including sense amplifiers connected to said bit lines to form an open bit line type semiconductor memory; and
a third region that is a region not sandwiched by said second regions, wherein said third region includes a plurality of dummy bit lines.
2. A semiconductor memory according to claim 1 , wherein said word lines extend in a second direction perpendicular to said first direction.
3. A semiconductor memory according to claim 1 , wherein said bit lines extend in said first direction.
4. A semiconductor memory according to claim 1 , wherein each one of said plurality of dummy bit lines and bit lines are alternately placed in said second direction in said third region.
5. A semiconductor memory according to claim 1 , wherein said plurality of dummy bit lines are not connected to said sense amplifiers.
6. A semiconductor memory according to claim 1 , wherein said plurality of dummy bit lines are connected to memory cells.
7. A semiconductor memory device comprising:
a plurality of memory mats arranged in line in a first direction; and
a plurality of sense amplifier blocks arranged in line in the first direction such that each of the sense amplifier blocks is sandwiched between adjacent ones of the memory mats and first and second memory mats among the memory mats are located respectively at one and the other ends of an arrangement of the memory mats and the sense amplifier blocks, each of the sense amplifier blocks including a plurality of sense amplifiers arranged in line in a second direction crossing the first direction;
each of the memory mats including:
a plurality of bit lines disposed in line in the second direction and each extending in the first direction,
a plurality of word lines disposed in line in the first direction and each extending in the second direction to cross each of the bit lines, and
a plurality of memory cells disposed respectively at all crossing points of the bit lines and the word lines,
a part of the bit lines of each of the memory mats except for the first and second memory mats being connected respectively to the sense amplifiers of an associated one of the sense amplifier blocks and a remaining part of the bit lines of each of the memory mats except for the first and second memory mats being connected respectively to the sense amplifiers of an associated another one of the sense amplifier blocks,
all of the bit lines of the first memory mat being connected respectively to the sense amplifiers of an adjacent one of the sense amplifier blocks to the first memory mat, and all of the bit lines of the second memory mat being connected respectively to the sense amplifiers of an adjacent one of the sense amplifier blocks to the second memory mat,
each of the first and second memory mats further including a plurality of dummy bit lines each having no electrical connection to any one of the sense amplifiers and a plurality of memory cells disposed respectively at all crossing points of the dummy bit lines and the word lines.
8. The semiconductor memory as defined in claim 7 , wherein each of said sense amplifiers includes a first input/output node coupled with a corresponding one of said bit lines of an associated one of said memory mats adjacent thereto and a second input/output node coupled with a corresponding one of said bit lines of an associated another of said memory mats adjacent thereto.
9. The semiconductor memory as defined in claim 8 , wherein said part of the bit lines and said remaining part of the bit lines of each of the memory mats except for the first and second memory mats are alternately disposed in line in said second direction and said dummy bit lines and said bit lines of each of said first and second memory mats are alternately disposed in line in said second direction.
10. The semiconductor memory as defined in claim 7 , wherein said first and second memory mats are simultaneously activated and the memory mats except for said first and second memory mats are activated individually.
11. The semiconductor memory as defined in claim 7 , wherein the memory mats except for said first and second memory mats comprise third, fourth and fifth memory mats, the fourth memory mat being between the third and fifth memory mats, said first, second and fourth memory mats being simultaneously activated in a first access condition, and said third and fifth memory mats being simultaneously activated in a second access condition.
12. The semiconductor memory as defined in claim 11 , wherein, in said first access condition, a half of said fourth memory mat and said first memory mat make a pair and the other half of said fourth memory mat and said second memory make another pair.