Semiconductor device having air-gap and method for manufacturing the same
A semiconductor device in which an air-gap located at a side of a bit line stack is extended to an upper part of the bit line stack is disclosed. An embodiment includes: a bit line stack; a plurality of storage node contacts located at both sides of the bit line stack; and an air-gap located between the bit line stack and the storage node contacts, and extended above the bit line stack.
1. A semiconductor device comprising:
a bit line stack;
a plurality of storage node contacts located at both sides of the bit line stack; and
an air-gap located between the bit line stack and the storage node contacts, and extended above the bit line stack,
wherein the bit line stack includes:
a conductive line; and
a hard mask stacked on the conductive line.
2. The semiconductor device according to claim 1 , wherein the storage node contacts include:
a first storage node contact; and
a second storage node contact above the first storage node contact and the bit line stack.
3. The semiconductor device according to claim 2 , wherein a top surface of the first storage node contact is below a top surface of the bit line stack.
4. The semiconductor device according to claim 2 , wherein the air-gap is extended above a top surface of the second storage node contact.
5. The semiconductor device according to claim 2 , wherein the air-gap includes:
a first air-gap located at both sidewalls of the bit line stack; and
a second air-gap interposed between the second storage node contacts, which are contiguous, and having a double-layered structure extending from the first air-gap.
6. The semiconductor device according to claim 5 , wherein the first air-gap has a single-layered structure.
7. The semiconductor device according to claim 5 , wherein the second air-gap extends from one of the first air-gaps located at both sides of the bit line stack.
8. The semiconductor device according to claim 5 , wherein the second air-gap has a double-layered structure in which air-gaps are respectively located at facing sidewalls of the second storage node contacts on the basis of the bit line stack interposed therebetween.
9. The semiconductor device according to claim 5 , wherein the first air-gap is in a spacer insulation film of the bit line stack.
10. The semiconductor device according to claim 5 , wherein the second air-gap has a U-shaped structure.