Semiconductor memory device

1. A semiconductor memory device comprising:

a memory cell array including a plurality of memory cells;

a row decoder connected to the memory cell array through word lines;

a plurality of page buffers connected to the memory cell array through bit lines; and

a voltage switching circuit configured to decode an operation voltage and transmit the decoded operation voltage to the row decoder,

wherein the plurality of page buffers are formed in a first under cell region among first and second under cell regions, the first and second under cell regions being adjacent to each other in a first direction under the memory cell array,

wherein at least a portion of the voltage switching circuit is formed in an under slim region that is adjacent to the first under cell region and the second under cell region in a second direction,

wherein the voltage switching circuit includes a first switch circuit and a second switch circuit, and

wherein the first switch circuit is formed in the second under cell region, and the second switch circuit is formed in the under slim region.

2. The semiconductor memory device of claim 1 , wherein the first direction and the second direction form substantially a right angle.

3. The semiconductor memory device of claim 1 , wherein the row decoder is formed on the under slim region.

4. The semiconductor memory device of claim 1 , wherein the first under cell region includes at least one bit line connector region that extends in the second direction, and

wherein switches that are included in the second switch circuit are formed to be adjacent to the bit line connector region in the second direction in the under slim region.

5. The semiconductor memory device of claim 4 , wherein the first switch circuit includes a first circuit block, a second circuit block, a third circuit block, and a fourth circuit block,

wherein the first circuit block switches a plurality of voltages and transmits a switched voltage to the second circuit block,

wherein the second circuit block selectively outputs the voltage that is received from the first circuit block to any one of a first output terminal and a second output terminal,

wherein the third circuit block selectively outputs any one of an internal low voltage, an external power voltage, a core voltage, and a ground voltage to the first output terminal, and

wherein the fourth circuit block selects any one of the internal low voltage, the external power voltage, the core voltage, and the ground voltage and outputs the selected one to the second output terminal.

6. The semiconductor memory device of claim 5 , wherein the first circuit block comprises:

a first switch selectively transmitting a first pass voltage to the second circuit block;

a second switch selectively transmitting a second pass voltage to the second circuit block;

a third switch selectively transmitting a third pass voltage to the second circuit block; and

a fourth switch transmitting an initialization voltage to the second circuit block.

7. The semiconductor memory device of claim 6 , wherein the second circuit block comprises:

a fifth switch selectively transmitting the voltage that is received from the first circuit block to the first output terminal; and

a sixth switch selectively transmitting the voltage that is received from the first circuit block to the second output terminal.

8. The semiconductor memory device of claim 7 , wherein the third circuit block comprises:

a seventh switch connected to the first output terminal;

an eighth switch selectively transmitting the internal low voltage to the seventh switch;

a ninth switch selectively transmitting the core voltage to the seventh switch;

a tenth switch selectively transmitting the external power voltage to the seventh switch; and

an eleventh switch selectively transmitting the ground voltage to the seventh switch.

9. The semiconductor memory device of claim 8 , wherein the fourth circuit block comprises:

a twelfth switch connected to the second output terminal;

a thirteenth switch selectively transmitting the internal low voltage to the twelfth switch;

a fourteenth switch selectively transmitting the core voltage to the twelfth switch;

a fifteenth switch selectively transmitting the external power voltage to the twelfth switch; and

a sixteenth switch selectively transmitting the ground voltage to the twelfth switch.

10. The semiconductor memory device of claim 5 , wherein the second switch circuit comprises:

a seventeenth switch selectively transmitting the voltage that is received from the first output terminal to a third output terminal;

an eighteenth switch selectively transmitting a select global word line voltage to the third output terminal; and

a nineteenth switch transmitting an internal power voltage to the third output terminal.

11. The semiconductor memory device of claim 10 , wherein the second switch circuit further comprises:

a twentieth switch selectively transmitting the voltage that is received from the second output terminal to a fourth output terminal;

a twenty-first switch selectively transmitting the select global word line voltage to the fourth output terminal; and

a twenty-second switch transmitting the internal power voltage to the fourth output terminal.

12. The semiconductor memory device of claim 1 , further comprising:

a voltage generator configured to generate the operation voltage and transmit the generated operation voltage to the voltage switching circuit.