Insulator, capacitor with the same and fabrication method thereof, and method for fabricating semiconductor device
View Patent ↗Disclosed is a multilayer insulator, a metal-insulator-metal (MIM) capacitor with the same, and a fabricating method thereof. The capacitor includes: a first electrode; an insulator disposed on the first electrode, the insulator including: a laminate structure in which an aluminum oxide (Al 2 O 3 ) layer and a hafnium oxide (HfO 2 ) layer are laminated alternately in an iterative manner and a bottom layer and a top layer are formed of the same material; and a second electrode disposed on the insulator.
1. An insulator, comprising:
a laminate structure in which two or more aluminum oxide (Al 2 O 3 ) layers and two or more hafnium oxide (HfO 2 ) layers are laminated alternately in an iterative manner and a bottom layer and a top layer are formed of the same material, the two or more hafnium oxide (HfO 2 ) layers not crystallized, and the aluminum oxide (Al 2 O 3 ) layers in the laminate structure each having the same thickness, the total thickness of the aluminum oxide (Al 2 O 3 ) layers being smaller than the total thickness of the hafnium oxide (HfO 2 ) layers in the laminate structure,
wherein an upper surface of the bottom layer has a greater surface area than an upper surface of the top layer such that a portion of the bottom layer extends outside the top layer;
an upper surface of at least one layer of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers has a substantially equal surface area as the upper surface of the top layer; and
an upper surface of at least one other layer of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers has a substantially equal surface area as the upper surface of the bottom layer, such that a portion of the laminate structure disposed on the bottom layer outside the top layer has a thickness that is less than a portion of the laminate structure covered with the top layer.
2. The insulator of claim 1 , wherein the bottom layer and the top layer are formed of an aluminum oxide (Al 2 O 3 ) material.
3. The insulator of claim 1 , wherein the bottom layer and the top layer are formed of a hafnium oxide (HfO 2 ) material.
4. The insulator of claim 1 , wherein the number of the alternate laminations of the aluminum oxide (Al 2 O 3 ) layer and the hafnium oxide (HfO 2 ) layer is approximately 2 to approximately 1500.
5. The insulator of claim 1 , wherein the ratio of the total thickness of the aluminum oxide (Al 2 O 3 ) layer with respect to the total thickness of the laminate structure is approximately 10% to approximately 30%.
6. The insulator of claim 1 , wherein the total thickness of the laminate structure is approximately 20 Å to approximately 3000 Å.
7. The insulator of claim 1 , wherein the hafnium oxide (HfO 2 ) layers in the laminate structure each have the same thickness.
8. The insulator of claim 1 , wherein the hafnium oxide (HfO 2 ) layers in the laminate structure are have different thicknesses.
9. The insulator of claim 1 , wherein the bottom layer and the top layer are formed to be thicker than the other layers in the laminate structure.
10. The insulator of claim 1 , wherein the bottom layer and the top layer are formed to be thinner than the other layers in the laminate structure.
11. The insulator of claim 1 , wherein the aluminum oxide (Al 2 O 3 ) layers are formed to a thickness of approximately 5 Å to approximately 10 Å.
12. The insulator of claim 1 , wherein the hafnium oxide (HfO 2 ) layers are formed to a thickness of approximately 10 Å to approximately 40 Å.
13. The insulator of claim 1 , wherein at least one of the aluminum oxide (Al 2 O 3 ) layers and at least one of the hafnium oxide (HfO 2 ) layers are doped with one of lanthanide elements.
14. The insulator of claim 1 , wherein the aluminum oxide (Al 2 O 3 ) layer and the hafnium oxide (HfO 2 ) layer are deposited using a plasma enhanced atomic layer deposition (PEALD) process or a thermal ALD process.
15. A capacitor comprising:
a first metal containing electrode;
an insulator disposed directly on the first metal containing electrode, the insulator including:
a laminate structure in which two or more aluminum oxide (Al 2 O 3 ) layers and two or more hafnium oxide (HfO 2 ) layers are laminated alternately in an iterative manner and a bottom layer and a top layer are formed of the same material, the two or more hafnium oxide (HfO 2 ) layers not crystallized, and the aluminum oxide (Al 2 O 3 ) layers in the laminate structure each having the same thickness, the total thickness of the aluminum oxide (Al 2 O 3 ) layers being smaller than the total thickness of the hafnium oxide (HfO 2 ) layers in the laminate structure; and
a second metal containing electrode disposed directly on a surface of the insulator opposite from the first metal containing electrode,
wherein an upper surface of the bottom layer of the laminate structure has a greater surface area than an upper surface of the top layer such that a portion of the bottom layer extends outside the top layer;
an upper surface of at least one layer of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers has a substantially equal surface area as the upper surface of the top layer; and
an upper surface of at least one other layer of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers has a substantially equal surface area as the upper surface of the bottom layer, such that a portion of the laminate structure disposed on the bottom layer outside the top layer has a thickness that is less than a portion of the laminate structure covered with the top layer.
16. The capacitor of claim 15 , wherein the first metal containing electrode and the second metal containing electrode comprise one of a metal layer, a metal nitride layer, and a laminate layer thereof.
17. The capacitor of claim 16 , wherein the metal layer comprises one of transition metal layers and the metal nitride layer comprises one of transition metal nitride layers.
18. The capacitor of claim 15 , wherein the first metal containing electrode and the second metal containing electrode are formed of the same material.
19. The capacitor of claim 15 , wherein the first metal containing electrode and the second metal containing electrode are formed of different materials.
20. The capacitor of claim 15 , further comprising a second insulating layer formed on the second metal containing electrode, and an interconnection formed on the second metal containing electrode, a via being provided to electrically connect the second metal containing electrode to the interconnection.
21. The capacitor of claim 15 , wherein the number of the alternate laminations of the aluminum oxide (Al 2 O 3 ) layers and the hafnium oxide (HfO 2 ) layers is 9 or more and 1500 or less.
22. The insulator of claim 4 , wherein the number of the alternate laminations of the aluminum oxide (Al 2 O 3 ) layers and the hafnium oxide (HfO 2 ) layers is 9 or more.
23. The capacitor of claim 15 , wherein the hafnium oxide (HfO 2 ) layers are each formed to a thickness of 40 Å or less.
24. The capacitor of claim 15 , wherein at least one of the aluminum oxide (Al 2 O 3 ) layers and at least one of the hafnium oxide (HfO 2 ) layers are doped with one of lanthanide elements.
25. A capacitor comprising:
a first metal containing electrode;
an insulator disposed directly on the first metal containing electrode, the insulator including:
a laminate structure in which two or more aluminum oxide (Al 2 O 3 ) layers and two or more hafnium oxide (HfO 2 ) layers are laminated alternately in an iterative manner and a bottom layer and a top layer are formed of the same material, the hafnium oxide (HfO 2 ) layers each formed to a thickness of 40 Å or less, and the aluminum oxide (Al 2 O 3 ) layers in the laminate structure each having the same thickness, the total thickness of the aluminum oxide (Al 2 O 3 ) layers being smaller than the total thickness of the hafnium oxide (HfO 2 ) layers in the laminate structure; and
a second metal containing electrode disposed directly on a surface of the insulator opposite from the first metal containing electrode,
wherein an upper surface of the bottom layer of the laminate structure has a greater surface area than an upper surface of the top layer such that a portion of the bottom layer extends outside the top layer;
an upper surface of at least one layer of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers has a substantially equal surface area as the upper surface of the top layer; and
an upper surface of at least one other layer of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers has a substantially equal surface area as the upper surface of the bottom layer, such that a portion of the laminate structure disposed on the bottom layer outside the top layer has a thickness that is less than a portion of the laminate structure covered with the top layer.
26. The capacitor of claim 25 , wherein at least one of the aluminum oxide (Al 2 O 3 ) layers and at least one of the hafnium oxide (HfO 2 ) layers are doped with one of lanthanide elements.
27. The capacitor of claim 25 , wherein the aluminum oxide (Al 2 O 3 ) layers and the hafnium oxide (HfO 2 ) layers are deposited using a plasma enhanced atomic layer deposition (PEALD) process.
28. The capacitor of claim 25 , wherein the number of the alternate laminations of the aluminum oxide (Al 2 O 3 ) layers and the hafnium oxide (HfO 2 ) layers is 9 or more.
29. The capacitor of claim 15 , further comprising a second insulating layer formed on the second metal containing electrode and a via filled with a conductive material provided in the second insulating layer,
wherein the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers in the laminate structure are laminated with parallel planar surfaces, and the via extends perpendicular to the parallel planar surfaces of the two or more aluminum oxide (Al 2 O 3 ) layers and the two or more hafnium oxide (HfO 2 ) layers from the second metal containing electrode.
30. The capacitor of claim 15 , wherein a portion of the insulator is disposed under the second metal containing electrode while a portion of the insulator extends laterally outside of the second metal containing electrode such that the portion of the insulator disposed under the second metal containing electrode has a greater thickness than the portion of the insulator disposed outside the second metal containing electrode.
31. The capacitor of claim 25 , wherein a portion of the insulator is disposed under the second metal containing electrode while a portion of the insulator extends laterally outside of the second metal containing electrode such that the portion of the insulator disposed under the second metal containing electrode has a greater thickness than the portion of the insulator disposed outside the second metal containing electrode.
32. The capacitor of claim 30 , wherein the portion of the insulator disposed outside the second metal containing electrode has a thickness that is equal to or less than approximately ½ of a thickness of the portion of the insulator disposed under the second metal containing electrode.