Semiconductor memory device with plurality of arrays
According to an embodiment, a semiconductor memory device includes a first memory cell array, a second memory cell array, and a row decoder. The first memory cell array includes a first select transistor, a first memory cell, a second select transistor, a first word line, a first select gate line, and a second select gate line. The second memory cell array includes, a third select transistor, a second memory cell, a fourth select transistor, a second word line, a third select gate line, a fourth select gate line. The first word line and the second word line are commonly coupled to the row decoder. The first select gate line, the second select gate line, the third select gate line, and the fourth select gate line are separately coupled to the row decoder.
1. A semiconductor memory device comprising:
a first memory cell array;
a second memory cell array arranged above the first memory cell array in a first direction; and
a row decoder,
wherein the first memory cell array includes:
a first select transistor;
a first memory cell;
a second select transistor, the first select transistor, the first memory cell, and the second select transistor being arranged along the first direction and coupled in series;
a first word line extending in a second direction crossing the first direction and coupled to the first memory cell;
a first select gate line extending in the second direction and coupled to a gate of the first select transistor; and
a second select gate line extending in the second direction and coupled to a gate of the second select transistor,
the second memory cell array includes:
a third select transistor;
a second memory cell;
a fourth select transistor, the third select transistor, the second memory cell, and the fourth select transistor being arranged along the first direction and coupled in series;
a second word line extending in the second direction and coupled to the second memory cell;
a third select gate line extending in the second direction and coupled to a gate of the third select transistor; and
a fourth select gate line extending in the second direction and coupled to a gate of the fourth select transistor,
the first word line and the second word line are commonly coupled to the row decoder,
the first select gate line, the second select gate line, the third select gate line, and the fourth select gate line are separately coupled to the row decoder,
the first memory cell array further includes:
a first contact plug extending in the first direction and provided on the first word line; and
a second contact plug passing through the first word line and the second select gate line and not electrically coupled to the first word line and the second select gate line,
the second memory cell array further includes
a third contact plug extending in the first direction and provided on the second word line, and
the first word line is electrically coupled to the second word line via the first contact plug, the second contact plug, and the third contact plug.
2. The device according to claim 1 , wherein
in a read operation of the first memory cell, the first select transistor and the second select transistor are set in an ON state, and the third select transistor and the fourth select transistor are set in an OFF state.
3. The device according to claim 1 , wherein
the first memory cell array further includes a first bit line coupled to a drain of the first select transistor, and a first source line coupled to a source of the second select transistor,
the second memory cell array further includes a second bit line coupled to a drain of the third select transistor, and a second source line coupled to a source of the fourth select transistor,
the first bit line and the second bit line are electrically coupled, and
the first source line and the second source line are electrically coupled.
4. The device according to claim 1 , wherein
the first select gate line, the first word line, and the second select gate line are stacked apart in the first direction, and end portions of the first select gate line, the first word line, and the second select gate line are arranged in a staircase shape in the second direction.
5. The device according to claim 1 , wherein
the first memory cell array further includes a memory pillar passing through the first word line, the first select gate line, and the second select gate line and extending in the first direction,
the first memory cell is formed by a combination of the first word line and the memory pillar,
the first select transistor is formed by a combination of the first select gate line and the memory pillar, and
the second select transistor is formed by a combination of the second select gate line and the memory pillar.
6. The device according to claim 5 , wherein
the memory pillar includes a semiconductor layer and a charge storage layer.
7. The device according to claim 1 , wherein
in the first direction, the first memory cell array is arranged between the row decoder and the second memory cell array.
8. The device according to claim 3 , further comprising a sense amplifier,
wherein the first bit line and the second bit line are commonly coupled to the sense amplifier.
9. The device according to claim 1 , further comprising:
a first chip including the first memory cell array;
a second chip including the second memory cell array; and
a third chip including the row decoder,
wherein the second chip is bonded to a first surface of the first chip, and
the third chip is bonded to a second surface of the first chip facing the first surface.
10. The device according to claim 1 , wherein
one end of the first word line and one end of the second word line are commonly coupled to the row decoder, and the other end of the first word line and the other end of the second word line are coupled to each other.
11. The device according to claim 10 , wherein
in a read operation of the first memory cell, the first select transistor and the second select transistor are set in an ON state, and the third select transistor and the fourth select transistor are set in an OFF state.