Semiconductor memory device
A semiconductor memory device includes a memory cell array and bit lines connected to the memory cell array. The semiconductor memory device also includes a first upper line and a second upper line which overlap with the bit lines and are spaced apart from the bit lines by different distances.
1. A semiconductor memory device comprising:
a common source line formed on a substrate;
a memory cell array formed on the common source line;
bit lines connected to the memory cell array;
an insulating layer extending to overlap with the bit lines, the insulating layer including a first region and a second region, wherein a thickness of the insulating layer in the first region is thinner than a thickness of the insulating layer in the second region;
a first upper line overlapping with the first region of the insulating layer; and
a second upper line overlapping with the second region of the insulating layer.
2. The semiconductor memory device of claim 1 , wherein the first upper line is configured to transmit an erase voltage, and the second upper line is configured to transmit a ground voltage.
3. The semiconductor memory device of claim 1 , wherein a width of the first upper line is wider than a width of the second upper line.
4. The semiconductor memory device of claim 1 , wherein the first upper line is configured to transmit an erase voltage applied to the first upper line to the bit lines through capacitive coupling.
5. The semiconductor memory device of claim 1 , wherein the memory cell array comprises:
a gate stack structure including interlayer insulating layers alternately stacked with conductive patterns; and
channel structures penetrating the gate stack structure, the channel structures being connected to the common source line,
wherein each of the channel structures is connected to a corresponding bit line among the bit lines.
6. The semiconductor memory device of claim 5 , wherein the common source line comprises a contact region which does not overlap with the gate stack structure.
7. The semiconductor memory device of claim 6 , further comprising a conductive source contact structure extending toward the first upper line from the contact region of the common source line.
8. The semiconductor memory device of claim 1 , wherein the substrate comprises a peripheral circuit and an internal voltage generator for providing internal voltages to the peripheral circuit, and
wherein the peripheral circuit includes a source line driver for at least one of providing an erase voltage to the common source line and discharging the common source line.
9. The semiconductor memory device of claim 8 , wherein the first upper line connects the common source line to the source line driver, and
the second upper line connects the internal voltage generator to the peripheral circuit.
10. The semiconductor memory device of claim 1 , wherein each of the first upper line and the second upper line extend in a zigzag form along an extending direction of the bit lines.
11. A semiconductor memory device comprising:
a common source line formed on a substrate;
a memory cell array formed on the common source line;
bit lines connected to the memory cell array;
an insulating layer extending to overlap with the bit lines;
a first upper line formed on the insulating layer; and
a second upper line formed on the insulating layer, the second upper line being spaced farther apart from the bit lines than the first upper line.
12. The semiconductor memory device of claim 11 , wherein the insulating layer includes a depression part into which the first upper line is inserted and a protrusion part supporting the second upper line.
13. The semiconductor memory device of claim 11 , wherein the first upper line is configured to transmit an erase voltage, and the second upper line is configured to transmit a ground voltage.
14. The semiconductor memory device of claim 11 , wherein a width of the first upper line is wider than a width of the second upper line.
15. The semiconductor memory device of claim 11 , wherein the first upper line is configured to transmit an erase voltage applied to the first upper line to the bit lines through capacitive coupling.
16. The semiconductor memory device of claim 11 , wherein the memory cell array comprises:
a gate stack structure including interlayer insulating layers alternately stacked with conductive patterns; and
channel structures penetrating the gate stack structure, the channel structures being connected to the common source line,
wherein each of the channel structures is connected to a corresponding bit line among the bit lines.