Semiconductor device including variable resistance layer
A semiconductor device according to an embodiment includes a substrate, a gate structure disposed on the substrate, a hole pattern penetrating the gate structure on the substrate, and a first variable resistance layer, a second variable resistance layer, and a channel layer sequentially disposed on a sidewall surface of the gate structure. The gate structure includes at least one gate electrode layer and at least one interlayer insulation layer that are alternately stacked. The first and second variable resistance layers include ions exchangeable with each other.
1. A semiconductor device comprising:
a substrate;
a gate structure disposed on the substrate, the gate structure comprising at least one gate electrode layer and at least one interlayer insulation layer that are alternately stacked;
a hole pattern penetrating the gate structure on substrate; and
a first variable resistance layer, a second variable resistance layer, and a channel layer sequentially disposed on a sidewall surface of the gate electrode layer in the hole pattern,
wherein the first and second variable resistance layers comprise ions exchangeable with each other.
2. The semiconductor device of claim 1 , wherein the second variable resistance layer has a variable oxygen vacancy concentration, based on an oxygen exchange with the first variable resistance layer.
3. The semiconductor device of claim 2 , wherein the second variable resistance layer stores in a non-volatile manner a plurality of different electrical resistances according to the variable oxygen vacancy concentration.
4. The semiconductor device of claim 2 , wherein the variable oxygen vacancy concentration of the second variable resistance layer varies by an electric field applied between the at least one gate electrode layer and the channel layer.
5. The semiconductor device of claim 1 , further comprising:
a channel lower contact layer contacting a first end of the channel layer on the substrate; and
a channel upper contact layer contacting a second end of the channel layer opposite to the first end,
wherein the channel lower contact layer and the channel upper contact layer are electrically connected to a source electrode and a drain electrode, respectively.
6. The semiconductor device of claim 1 , wherein each of the first and second variable resistance layers comprises an oxygen-deficient oxide, and
wherein the oxygen-deficient oxide comprises silicon oxide or metal oxide.
7. The semiconductor device of claim 6 , wherein an oxygen affinity of an element of the first variable resistance layer is greater than an oxygen affinity of an element of the second variable resistance layer.
8. The semiconductor device of claim 1 , wherein when a program voltage is applied to the at least one gate electrode layer, the first variable resistance layer functions as an oxygen receiving layer, and the second variable resistance layer functions as an oxygen supply layer, and
wherein when an erase voltage is applied to the at least one gate electrode layer, the first variable resistance layer functions as an oxygen supply layer, and the second variable resistance layer functions as an oxygen receiving layer.
9. The semiconductor device of claim 1 , wherein the first and second variable resistance layers comprise metal exchangeable with each other, and
wherein when a program voltage is applied to the at least one gate electrode layer, the first variable resistance layer functions as a metal supply layer, and the second variable resistance layer functions as a metal receiving layer, and
when an erase voltage is applied to the at least one gate electrode layer, the first variable resistance layer functions as a metal receiving layer, and the second variable resistance layer functions as a metal supply layer.
10. The semiconductor device of claim 9 , wherein when the program voltage is applied, metal moving from the first variable resistance layer to the second variable resistance layer has a greater mobility than oxygen moving from the second variable resistance layer to the first variable resistance layer.
11. The semiconductor device of claim 1 , wherein a thickness of the second variable resistance layer is less than a thickness of the first variable resistance layer.
12. The semiconductor device of claim 11 , wherein a thickness of the second variable resistance layer is 1 nm or more, but less than 5 nm.
13. The semiconductor device of claim 1 , further comprising a gate insulation layer disposed between a sidewall surface of the gate structure and the first variable resistance layer.
14. A semiconductor device comprising:
a substrate;
a gate structure disposed on the substrate, the gate structure comprising at least one gate electrode layer and at least one interlayer insulation layer that are alternately stacked along a first direction perpendicular to an upper surface of the substrate, wherein the gate structure extends in a second direction perpendicular to the first direction; and
a first variable resistance layer, a second variable resistance layer, and a channel layer that are sequentially disposed on a sidewall surface of the gate structure on the substrate,
wherein the first and second variable resistance layers comprise oxygen exchangeable with each other.
15. The semiconductor device of claim 14 , wherein the second variable resistance layer has a variable oxygen vacancy concentration, based on oxygen exchange with the first variable resistance layer.
16. The semiconductor device of claim 15 , wherein the second variable resistance layer stores in a nonvolatile manner a plurality of different electrical resistances according to the variable oxygen vacancy concentration.
17. The semiconductor device of claim 14 , further comprising:
a channel lower contact layer, disposed between the gate structure and the substrate, contacting a first end of the channel layer on the substrate; and
a channel upper contact layer contacting a second end of the channel layer opposite to the first end,
wherein the channel lower contact layer and the channel upper contact layer are electrically connected to a source electrode and a drain electrode, respectively.
18. The semiconductor device of claim 17 , further comprising a plurality of cell insulation structures disposed on the substrate and spaced apart from each other in the second direction,
wherein the plurality of cell insulation structures extend in the first direction on the substrate, and extend in a third direction perpendicular to the first and second directions and separate the first variable resistance layer, the second variable resistance layer and the channel layer with respect to the second direction.
19. The semiconductor device of claim 14 , wherein the at least one interlayer insulation layer extends in a third direction perpendicular to the first and second directions and is disposed to contact the channel layer.
20. The semiconductor device of claim 14 , further comprising a gate insulation layer disposed between on the substrate a sidewall surface of the gate structure and the first variable resistance layer.