Semiconductor devices having air spacer
A semiconductor device includes bit line structures disposed on a substrate, each bit line structure comprising a bit line and an insulating spacer structure, buried contacts which fill lower portions of spaces between bit line structures in the substrate, and landing pads which fill upper portions of the spaces, extend from upper surfaces of the buried contacts to upper surfaces of the bit line structures, and are spaced apart from each other by insulating structures. A first insulating structure is disposed between a first landing pad and a first bit line structure. The first insulating structure includes a sidewall extending along a sidewall of the first landing pad toward the substrate. In a direction extending toward the substrate, the sidewall of the first insulating structure gets closer to a first sidewall of the first bit line structure.
1. A semiconductor device comprising:
a substrate in which a plurality of active regions are defined;
a plurality of bit line structures disposed on the substrate, each of the plurality of bit line structures comprising a bit line and an insulating spacer structure, the insulating spacer structure covering a sidewall of the bit line and having an air spacer, and the bit line structures being spaced apart from each other in a first horizontal direction and extending parallel to each other in a second horizontal direction different from the first horizontal direction;
a plurality of buried contacts and a plurality of insulating fences disposed in lower portions of spaces between the plurality of bit line structures, the plurality of buried contacts and the plurality of insulating fences being alternately arranged in the second horizontal direction;
a plurality of landing pads which fill upper portions of the spaces between the plurality of bit line structures, extend in a vertical direction from upper surfaces of the plurality of buried contacts to upper surfaces of the plurality of bit line structures, and are electrically connected to the plurality of active regions via the plurality of buried contacts;
a plurality of recess portions,
wherein each of the plurality of recess portions extends toward the substrate from between two landing pads, which are spaced apart from each other in the first horizontal direction, among the plurality of landing pads, and
wherein a first recess portion of the plurality of recess portions is defined by a sidewall of a first landing pad of the two landing pads and a first sidewall of a first bit line structure of the plurality of bit line structures; and
a plurality of insulating structures filling the plurality of recess portions,
wherein the plurality of landing pads are spaced apart from each other by the plurality of insulating structures,
wherein a second landing pad of the two landing pads is disposed on an upper surface of the first bit line structure and a second sidewall, opposite to the first sidewall, of the first bit line structure,
wherein in a direction extending toward the substrate, the sidewall of the first landing pad gets closer to the first sidewall of the first bit line structure,
wherein between the two landing pads, a first insulating structure of the insulating structures has a bottom surface of which at least a portion is flat in the second horizontal direction, and
wherein, between the first landing pad and the first bit line structure which are spaced apart from each other in the first horizontal direction, a center, in the first horizontal direction, of a lower end of the first insulating structure of the plurality of insulating structures and a center, in the first horizontal direction, of an upper end of an air spacer of the first bit line structure are vertically aligned with each other.
2. The semiconductor device of claim 1 ,
wherein a center, in the first horizontal direction, of a bottom surface of the first recess portion and the center, in the first horizontal direction, of the upper end of the air spacer of the first bit line structure are vertically aligned with each other.
3. The semiconductor device of claim 1 ,
wherein top surfaces of the plurality of insulating fences contact bottom surfaces of the plurality of insulating structures.
4. The semiconductor device of claim 1 ,
wherein, between the two landing pads which are spaced apart from each other in the first horizontal direction, a center, in the first horizontal direction, of an upper end of the first insulating structure and the center, in the first horizontal direction, of the upper end of the air spacer of the first bit line structure, when viewed in a top down view, are spaced apart from each other in the first horizontal direction.
5. The semiconductor device of claim 1 ,
wherein the first recess portion extends toward the air spacer of the first bit line structure from between the two landing pads which are spaced apart from each other in the first horizontal direction, and
wherein a width, in the first horizontal direction, of the first recess portion decreases toward the air spacer of the first bit line structure.
6. The semiconductor device of claim 1 ,
wherein each of the plurality of bit line structures further comprises an insulating capping line disposed on an upper surface of the bit line, and
wherein a portion of the first insulating structure is disposed between the first bit line structure and the first landing pad and has a maximum width, in the first horizontal direction, at a level of an upper surface of the insulating capping line.
7. The semiconductor device of claim 1 , wherein a bottommost end of the first insulating structure contacts the air spacer of the first bit line structure.
8. The semiconductor device of claim 1 ,
wherein the plurality of landing pads are arrayed in a row in the first horizontal direction and arrayed in a zigzag pattern in the second horizontal direction.
9. The semiconductor device of claim 1 ,
wherein a top surface of each of the plurality of landing pads is circular.
10. The semiconductor device of claim 1 , further comprising:
a plurality of storage nodes on the plurality of landing pads,
wherein the plurality of storage nodes are arranged in a hexagonal array pattern.
11. A semiconductor device comprising:
a substrate in which a plurality of active regions are defined;
a plurality of word lines being parallel to each other and extending in a first horizontal direction across the plurality of active regions;
a plurality of bit line structures disposed on the substrate, each of the plurality of bit line structures comprising a bit line and an insulating spacer structure, the insulating spacer structure covering a sidewall of the bit line and having an air spacer, and the bit line structures being parallel to each other and extending in a second horizontal direction perpendicular to the first horizontal direction;
a plurality of insulating fences that are arrayed in a row in the second horizontal direction in spaces between the plurality of bit line structures in the substrate;
a plurality of buried contacts which are arranged in spaces, which are defined by the plurality of bit line structures and the plurality of insulating fences, and electrically connected to the plurality of active regions, wherein the plurality of buried contacts and the plurality of insulating fences being alternately arranged in the second horizontal direction;
a plurality of landing pads disposed on the plurality of buried contacts, the plurality of landing pads extending from upper surfaces of the plurality of buried contacts to upper surfaces of the plurality of bit line structures; and
a plurality of insulating structures disposed between the plurality of landing pads,
wherein the plurality of landing pads and the plurality of insulating structures are alternately arranged in the second horizontal direction,
wherein a first insulating structure of the plurality of insulating structures is disposed between a first landing pad of the plurality of landing pads which are spaced apart from each other in the first horizontal direction with the plurality of insulating structures therebetween and a first bit line structure, adjacent to the first landing pad in the first horizontal direction, of the plurality of bit line structures,
wherein the first insulating structure of the insulating structures includes a sidewall extending along a sidewall of the first landing pad toward the substrate, and
wherein, between the first landing pad and the first bit line structure which are spaced apart from each other in the first horizontal direction, a center, in the first horizontal direction, of a lower end of the first insulating structure and a center, in the first horizontal direction, of an upper end of an air spacer of the first bit line structure are vertically aligned with each other.
12. The semiconductor device of claim 11 ,
wherein a center, in the first horizontal direction, of an upper end of the first insulating structure and the center, in the first horizontal direction, of the lower end of the first insulating structure, when viewed in a top down view, are spaced apart from each other in the first horizontal direction.
13. The semiconductor device of claim 11 ,
wherein top surfaces of the insulating fences contact bottom surfaces of the insulating structures.
14. The semiconductor device of claim 11 ,
wherein each of the plurality of landing pads comprises a conductive barrier pattern and a conductive pad pattern on the conductive barrier pattern.
15. The semiconductor device of claim 14 ,
wherein the conductive barrier pattern comprises a TiN layer or a laminated structure of a Ti layer and a TiN layer, and
wherein the conductive pad pattern comprises tungsten (W).
16. The semiconductor device of claim 11 ,
wherein a width, in the first horizontal direction, of a lower portion of the first insulating structure is smaller than a width, in the first horizontal direction, of an upper portion of the first insulating structure.
17. The semiconductor device of claim 11 ,
wherein a width, in the first horizontal direction, of the first insulating structure decreases toward the air spacer of the first bit line structure.
18. The semiconductor device of claim 11 ,
wherein, between two landing pads of the plurality of landing pads which are spaced apart from each other in the first horizontal direction with the first insulating structure therebetween, the first insulating structure has a bottom surface of which at least a portion is flat in the second horizontal direction.
19. The semiconductor device of claim 11 ,
wherein each of the plurality of bit line structures further comprises an insulating capping line disposed on an upper surface of the bit line, and
wherein a portion of the first insulating structure is disposed between the first bit line structure and the first landing pad and has a maximum width, in the first horizontal direction, at a level of an upper surface of the insulating capping line.
20. The semiconductor device of claim 11 ,
wherein a bottommost end of the first insulating structure contacts the air spacer of the first bit line structure.