Semiconductor device including vertical channel layer and method of manufacturing the same
A semiconductor device includes a substrate, a plurality of gate electrodes extending in a first direction parallel to an upper surface of a substrate on the substrate, and alternately arranged with an interlayer insulating layer in a second direction perpendicular to the upper surface of the substrate, a vertical channel layer on a sidewall of a vertical channel hole extending in the second direction by penetrating through the plurality of gate electrodes and the interlayer insulating layer, and connected to the upper surface of the substrate, and a first gap-fill insulating layer formed in the vertical channel hole and including an outer wall contacting the vertical channel layer and an inner wall opposite the outer wall, wherein a part of the inner wall forms a striation extending in the second direction.
1. A semiconductor device, comprising:
a substrate;
a plurality of gate electrodes on the substrate, the plurality of gate electrodes extending in a first direction parallel to an upper surface of the substrate and alternately arranged with an interlayer insulating layer in a second direction perpendicular to the upper surface of the substrate;
a vertical channel layer on a sidewall of a vertical channel hole extending in the second direction by penetrating through the plurality of gate electrodes and the interlayer insulating layer, and connected to the upper surface of the substrate; and
a first gap-fill insulating layer formed in the vertical channel hole and including an outer wall contacting the vertical channel layer and an inner wall opposite the outer wall, wherein a part of the inner wall projects inwardly to provide the inner wall with an uneven surface and forms a striation extending in the second direction.
2. The semiconductor device as claimed in claim 1 , wherein the inner wall of the first gap-fill insulating layer has a cross-section different from a circular shape.
3. The semiconductor device as claimed in claim 1 , wherein:
the outer wall of the first gap-fill insulating layer has a circular-shaped cross-section, and
the cross-section of the inner wall of the first gap-fill insulating layer has a polygonal shape including a plurality of projecting portions.
4. The semiconductor device as claimed in claim 1 , wherein:
the first gap-fill insulating layer has a non-uniform thickness in a direction perpendicular to the second direction, and
the vertical channel layer has a non-uniform thickness in a direction surrounding the first gap-fill insulating layer.
5. The semiconductor device as claimed in claim 1 , wherein:
the vertical channel layer includes an inner wall contacting an outer wall of the first gap-fill insulating layer and an outer wall opposite the inner wall,
the outer wall of the vertical channel layer has a striation at a first vertical level, and
the outer wall of the vertical channel layer does not have a striation at a second vertical level farther from the upper surface of the substrate than the first vertical level.
6. The semiconductor device as claimed in claim 5 , wherein:
at the first vertical level, the outer wall of the vertical channel layer has a cross-section different from a circular shape, and
at the first vertical level, the inner wall of the vertical channel layer has a circular-shaped cross-section.
7. The semiconductor device as claimed in claim 1 , wherein:
the inner wall of the first gap-fill insulating layer has a cross-section different from a circular shape at a first vertical level, and
the inner wall of the first gap-fill insulating layer has a circular shaped cross-section at a second vertical level farther from the upper surface of the substrate than the first vertical level.
8. The semiconductor device as claimed in claim 1 , further comprising:
a second gap-fill insulating layer in the vertical channel hole and contacting an inner wall of the first gap-fill insulating layer,
wherein the first and second gap-fill insulating layers completely fill the vertical channel hole or a void is formed in the second gap-fill insulating layer.
9. A semiconductor device, comprising:
a substrate;
a plurality of gate electrodes on the substrate, the plurality of gate electrodes extending in a first direction parallel to an upper surface of the substrate and alternately arranged with an interlayer insulating layer in a second direction perpendicular to the upper surface of the substrate;
a vertical channel layer on a sidewall of a vertical channel hole extending in the second direction by penetrating through the plurality of gate electrodes and the interlayer insulating layer; and
a first gap-fill insulating layer in the vertical channel hole and including an outer wall contacting the vertical channel layer and an inner wall opposite the outer wall, wherein the inner wall of the first gap-fill insulating layer has a cross-section different from a circular shape.
10. The semiconductor device as claimed in claim 9 , wherein:
a part of the vertical channel layer has a striation extending in the second direction, and
a part of the inner wall of the first gap-fill insulating layer has a striation extending in the second direction.
11. The semiconductor device as claimed in claim 9 , wherein
the inner wall of the first gap-fill insulating layer has a polygonal-shaped cross-section including a plurality of projecting portions, and
the outer wall of the first gap-fill insulating layer has a circular-shaped cross-section.
12. The semiconductor device as claimed in claim 9 , wherein:
the vertical channel layer includes an inner wall contacting the first gap-fill insulating layer and an outer wall opposite the inner wall,
the inner wall of the vertical channel layer has a circular-shaped cross-section, and
the outer wall of the vertical channel layer has a polygonal-shaped vertical cross-section including a plurality of projecting portions.
13. The semiconductor device as claimed in claim 9 , wherein:
the vertical channel layer has a non-uniform thickness along the first direction at a first vertical level adjacent to the upper surface of the substrate and a uniform thickness at a second vertical level spaced from the upper surface of the substrate along the second direction; and
the first gap-fill insulating layer has a non-uniform thickness at the first vertical level and a uniform thickness at the second vertical level.
14. The semiconductor device as claimed in claim 9 , wherein the inner wall of the first gap-fill insulating layer has a cross-section different from a circular shape at a first vertical level adjacent to the upper surface of the substrate and a circular-shaped cross-section at a second vertical level spaced from the upper surface of the substrate along the second direction.
15. A semiconductor device, comprising:
a substrate;
a plurality of gate electrodes on the substrate, the plurality of gate electrodes extending in a first direction parallel to an upper surface of the substrate and alternately arranged with an interlayer insulating layer in a second direction perpendicular to the upper surface of the substrate;
a vertical channel layer on a sidewall of a vertical channel hole extending in the second direction by penetrating through the plurality of gate electrodes and the interlayer insulating layer, and in contact with the upper surface of the substrate; and
a first gap-fill insulating layer in the vertical channel hole, the first gap-fill insulating layer having an inner wall and an outer wall opposite the inner wall,
wherein the inner wall of the first gap-fill insulating layer has a cross-section different from a circular shape at a first vertical level adjacent to the upper surface of the substrate and a circular-shaped cross-section at a second vertical level spaced from the upper surface of the substrate along the second direction.
16. The semiconductor device as claimed in claim 15 , wherein:
the vertical channel layer has a non-uniform thickness along the first direction at the first vertical level and a uniform thickness at the second vertical level; and
the first gap-fill insulating layer has a non-uniform thickness at the first vertical level and a uniform thickness at the second vertical level.
17. The semiconductor device as claimed in claim 16 , wherein:
a part of the vertical channel layer has a striation extending in the second direction, and
a part of the inner wall of the first gap-fill insulating layer has a striation extending in the second direction.
18. The semiconductor device as claimed in claim 16 , wherein an inner wall of the vertical channel layer and an outer wall of the first gap-fill insulating layer have a circular shape at both the first and second vertical levels.
19. The semiconductor device as claimed in claim 15 , wherein:
at the first vertical level, the inner wall of the first gap-fill insulating layer has a cross-section different from a circular shape, and
at the first vertical level, the outer wall of the first gap-fill insulating layer has a circular-shaped cross-section.
20. The semiconductor device as claimed in claim 15 , further comprising:
a second gap-fill insulating layer in the vertical channel hole and contacting an inner wall of the first gap-fill insulating layer,
wherein the first and second gap-fill insulating layers completely fill the vertical channel hole or a void is formed in the second gap-fill insulating layer.