Three-dimensional semiconductor memory device
In a three-dimensional semiconductor memory device, the device includes a semiconductor substrate having a recessed region, an active pattern extending in a direction transverse to the recessed region, an insulating pillar being adjacent to the active pattern and extending in the direction transverse to the recessed region, and a lower select gate facing the active pattern and extending horizontally on the semiconductor substrate. The active pattern is disposed between the insulating pillar and the lower select gate.
1. A three-dimensional semiconductor memory device comprising:
a semiconductor substrate having a recessed region;
an active pattern extending from the recessed region in a direction perpendicular to the substrate;
an insulating pillar being adjacent to the active pattern and extending in the direction perpendicular to the substrate; and
a lower select gate facing the active pattern and extending horizontally on the semiconductor substrate.
2. The three-dimensional semiconductor memory device of claim 1 , wherein the active pattern has a cylindrical shape.
3. The three-dimensional semiconductor memory device of claim 1 , wherein the active pattern is disposed to cover a lower surface and a side surface of the recessed region, and wherein the insulating pillar fills the recessed region in which the active pattern is disposed.
4. The three-dimensional semiconductor memory device of claim 3 , wherein the position of a lower surface of the insulating pillar is lower than that of an upper surface of the semiconductor substrate.
5. The three-dimensional semiconductor memory device of claim 1 , further comprising a common source line present in the semiconductor substrate and extending in parallel along a direction in which the lower select gate extends.
6. The three-dimensional semiconductor memory device of claim 5 , wherein the lower select gate controls a first channel region, which is defined in the semiconductor substrate between the active pattern and the common source line, and a second channel region, which is defined in the active pattern.
7. The three-dimensional semiconductor memory device of claim 6 , wherein the first channel region contains dopants which adjust a threshold voltage.
8. The three-dimensional semiconductor memory device of claim 7 , wherein the first channel region contains a first conductive type dopant, and the common source line contains a second conductive type dopant.
9. The three-dimensional semiconductor memory device of claim 1 , further comprising:
word lines and an upper select gate being disposed on the lower select gate so as to be spaced apart from each other and extending horizontally; and
information storage layers interposed between the active pattern and the lower select gate, between the active pattern and the word lines, and between the active pattern and the upper select line.
10. The three-dimensional semiconductor memory device of claim 1 , further comprising:
a p-well provided in the semiconductor substrate,
wherein the p-well comes into contact with the active pattern.
11. The three-dimensional semiconductor memory device of claim 1 , wherein the active pattern is disposed between the insulating pillar and the lower select gate.
12. The three-dimensional semiconductor memory device of claim 1 , wherein the active pattern contacts a lower surface of the recessed region.
13. A three-dimensional semiconductor memory device comprising:
a semiconductor substrate having a recessed region;
an active pattern extending from the recessed region in a direction perpendicular to the substrate; and
a lower select gate facing the active pattern and extending horizontally on the semiconductor substrate.
14. The three-dimensional semiconductor memory device of claim 13 , further comprising an insulating pillar adjacent to the active pattern and extending in the direction perpendicular to the substrate.
15. The three-dimensional semiconductor memory device of claim 13 , wherein the active pattern contacts with a lower surface of the recessed region.
16. The three-dimensional semiconductor memory device of claim 13 , further comprising an information storage layer disposed between the active pattern and the lower select gate.
17. A three-dimensional semiconductor memory device comprising:
a semiconductor substrate having a recessed region;
an active pattern extending from the recessed region in a direction perpendicular to the substrate;
an insulating pillar adjacent to the active pattern and extending in the direction perpendicular to the substrate; and
wherein the active pattern contacts a lower surface of the recessed region and wherein a bottom surface of the active pattern is lower than a bottom surface of the insulating pillar.
18. The three-dimensional semiconductor memory device of claim 17 , further comprising a lower select gate facing the active pattern and extending horizontally on the semiconductor substrate.
19. The three-dimensional semiconductor memory device of claim 18 , further comprising:
word lines disposed on the lower select gate; and
information storage layers interposed between the active pattern and the word lines.
20. The three-dimensional semiconductor memory device of claim 19 , wherein the information storage layers extends between the active pattern and the lower select gate.
21. The three-dimensional semiconductor memory device of claim 17 , wherein the active pattern is between the insulating pillar and the lower surface of the recessed region.