Variable resistance memory device and method of fabricating the same
A variable resistanvce memory device may include a plurality of first conductive lines extending in a first direction, a plurality of second conductive lines extending in a second direction, a plurality of memory cells, each memory cell at a respective intersection, with respect to a top down view, between a corresponding one of the first conductive lines and a corresponding one of the second conductive lines, each memory cell comprising a variable resistance structure and a switching element sandwiched between a top electrode and a bottom electrode, and a first dielectric layer filling a space between the switching elements of the memory cells. A top surface of the first dielectric layer is disposed between bottom and top surfaces of the top electrodes of the memory cells.
1. A variable resistance memory device, comprising:
a plurality of first conductive lines extending in a first direction;
a plurality of second conductive lines extending in a second direction;
a plurality of memory cells, each memory cell at a respective intersection, between a corresponding one of the first conductive lines and a corresponding one of the second conductive lines, each memory cell comprising a variable resistance structure and a switching element sandwiched between a top electrode and a bottom electrode;
a first dielectric layer filling a space between the switching elements of the memory cells; and
a third dielectric layer filling a space between the second conductive lines and extending between the top electrodes of the memory cells,
wherein a top surface of the first dielectric layer is disposed between bottom and top surfaces of the top electrodes of the memory cells, and
wherein the bottommost surface of the third dielectric layer is disposed between bottom and top surfaces of the top electrodes of the memory cells.
2. The variable resistance memory device of claim 1 , further comprising a second dielectric layer between the first dielectric layer and the third dielectric layer and filling a space between the top electrodes of the memory cells,
wherein the first dielectric layer has a dielectric constant less than a dielectric constant of the second dielectric layer.
3. The variable resistance memory device of claim 2 ,
wherein the third dielectric layer has a dielectric constant greater than the dielectric constant of the first dielectric layer.
4. The variable resistance memory device of claim 2 , wherein each of the top electrodes includes a first carbon electrode pattern, a metal pattern, and a second carbon electrode pattern that are sequentially stacked, and
wherein the top surface of the first dielectric layer is lower than a top surface of the metal pattern.
5. The variable resistance memory device of claim 4 , wherein the top surface of the first dielectric layer is higher than a bottom surface of the metal pattern.
6. The variable resistance memory device of claim 2 , wherein each of the top electrodes includes a carbon electrode pattern and a metal pattern on the carbon electrode pattern.
7. The variable resistance memory device of claim 6 , wherein a top surface of the metal pattern contacts the second conductive lines, and
wherein the top surface of the first dielectric layer is higher than a bottom surface of the metal pattern.
8. The variable resistance memory device of claim 2 , wherein each of the top electrodes includes a carbon electrode pattern, and
wherein the top surface of the first dielectric layer is higher than a bottom surface of the carbon electrode pattern and lower than a top surface of the carbon electrode pattern.
9. The variable resistance memory device of claim 2 , wherein the first dielectric layer contains carbon, and
wherein the second dielectric layer contains no carbon.
10. The variable resistance memory device of claim 1 , further comprising a sidewall dielectric layer between the first dielectric layer and the switching elements,
wherein a dielectric constant of the first dielectric layer is less than a dielectric constant of the sidewall dielectric layer.
11. The variable resistance memory device of claim 10 , wherein the sidewall dielectric layer extends onto a bottom surface of the first dielectric layer.
12. The variable resistance memory device of claim 10 , wherein the sidewall dielectric layer includes one or more of a silicon nitride and a silicon oxide.
13. The variable resistance memory device of claim 10 , further comprising a second dielectric layer on the first dielectric layer and filling a space between the top electrodes of the memory cells.
14. A variable resistance memory device, comprising:
a plurality of first conductive lines extending in a first direction;
a plurality of second conductive lines extending in a second direction;
a plurality of switching elements at intersections between the first conductive lines and the second conductive lines;
a plurality of variable resistance structures between the switching elements and the first conductive lines;
a plurality of top electrodes between the switching elements and the second conductive lines;
a first dielectric layer filling a space between the switching elements; and
a second dielectric layer on the first dielectric layer and filling a space between the top electrodes, the second dielectric layer having a dielectric constant greater than a dielectric constant of the first dielectric layer,
wherein a bottom surface of the first dielectric layer is higher than top surfaces of the variable resistance structures.
15. The variable resistance memory device of claim 14 , wherein a top surface of the first dielectric layer is disposed between bottom and top surfaces of the top electrodes.
16. The variable resistance memory device of claim 14 , further comprising a third dielectric layer on the second dielectric layer and filing a space between the second conductive lines,
wherein the third dielectric layer having a dielectric constant greater than a dielectric constant of the first dielectric layer.
17. The variable resistance memory device of claim 14 , wherein each of the top electrodes includes a carbon electrode pattern, and
wherein a top surface of the first dielectric layer is higher than a bottom surface of the carbon electrode pattern.
18. The variable resistance memory device of claim 14 , further comprising a sidewall dielectric layer between the first dielectric layer and the switching elements,
wherein the dielectric constant of the first dielectric layer is less than a dielectric constant of the sidewall dielectric layer.
19. The variable resistance memory device of claim 14 , wherein the first dielectric layer contains carbon, and
wherein the second dielectric layer contains no carbon.
20. A variable resistance memory device, comprising:
a plurality of first conductive lines extending in a first direction;
a plurality of second conductive lines extending in a second direction;
a plurality of memory cells, each memory cell at a respective intersection, with respect to a top down view, between a corresponding one of the first conductive lines and a corresponding one of the second conductive lines, each memory cell comprising a variable resistance structure and a switching element sandwiched between a top electrode and a bottom electrode;
a first dielectric layer filling a space between the switching elements of the memory cells;
a second dielectric layer on the first dielectric layer and filling a space between the top electrodes of the memory cells; and
a third dielectric layer extending in the second direction on the second dielectric layer and filling a space between the second conductive lines,
wherein a top surface of the first dielectric layer is disposed between bottom and top surfaces of the top electrodes of the memory cells,
wherein a dielectric constant of the first dielectric layer is less than a dielectric constant of each of the second and third dielectric layers, and
wherein the third dielectric layer contacts the second dielectric layer.