Stacked capacitor with symmetric leakage and break-down behaviors
A layered structure including a tri-stack dielectric layer and a plurality of metal layers insulated from each other by the tri-stack dielectric layer. The plurality of metal layers includes a set of first-type metal layers and a set of second-type metal layers. An adjacent pair of the plurality of metal layers includes a first-type metal layer and a second-type metal layer. The tri-stack dielectric layer includes a first tri-stack layer including Al 2 O 3 , a second tri-stack layer including HfO 2 ; and a third tri-stack layer including Al 2 O 3 .
1. A stacked planar capacitor, comprising:
a first metal layer;
a first tri-stack dielectric layer disposed on a surface of the first metal layer;
a second metal layer disposed on a surface of the first tri-stack dielectric layer;
a second tri-stack dielectric layer disposed on a surface of the second metal layer; and
a third metal layer disposed on a surface of the second tri-stack dielectric layer;
wherein each of the first tri-stack dielectric layer and the second tri-stack dielectric layer comprises:
a first tri-stack layer comprising Al 2 O 3 ;
a second tri-stack layer comprising HfO 2 ; and
a third tri-stack layer comprising Al 2 O 3 ;
wherein the first metal layer, the first tri-stack dielectric layer, and the second metal layer define a first capacitor comprising a first electrical bias polarity;
wherein the second metal layer, the second tri-stack dielectric layer, and the third metal layer define a second capacitor comprising a second electrical bias polarity, the second electrical bias polarity opposite the first electrical bias polarity; and
wherein a dielectric break-down behavior is symmetric for both biasing polarities.
2. The capacitor of claim 1 , wherein a thickness of each of the first metal layer, the second metal layer, and the third metal layer is about 200 Angstroms to about 400 Angstroms.
3. The capacitor of claim 1 , wherein each of the first metal layer, the second metal layer, and the third metal layer comprises TiN.
4. The capacitor of claim 1 , wherein a thickness of each of the first tri-stack layer and the second tri-stack layer is about 5 Angstroms to about 100 Angstroms.
5. The capacitor of claim 1 , wherein a thickness of each of the first tri-stack layer and the second tri-stack layer is about 10 Angstroms to about 80 Angstroms.
6. The capacitor of claim 1 , wherein a thickness of each of the first tri-stack layer and the second tri-stack layer is about 15 Angstroms to about 50 Angstroms.
7. The capacitor of claim 1 ,
wherein the second tri-stack layer comprising HfO 2 is disposed over the first tri-stack layer comprising Al 2 O 3 , and
wherein the third tri-stack layer comprising Al 2 O 3 is disposed over the second tri-stack layer comprising HfO 2 .
8. The capacitor of claim 7 ,
wherein a thickness of each of the first tri-stack layer comprising Al 2 O 3 and the third tri-stack layer comprising Al 2 O 3 is about 3 Angstroms to about 10 Angstroms; and
wherein a thickness of the second tri-stack layer comprising HfO 2 is about 10 Angstroms to about 60 Angstroms.
9. A method to form a planar capacitor, comprising:
providing a first metal layer,
disposing a first tri-stack dielectric layer on a surface of the first metal layer;
disposing a second metal layer on a surface of the first tri-stack dielectric layer;
disposing a second tri-stack dielectric layer on a surface of the second metal layer; and
disposing a third metal layer on a surface of the second tri-stack dielectric layer,
wherein each of the first tri-stack dielectric layer and the second tri-stack dielectric layer comprises:
a first tri-stack layer comprising Al 2 O 3 ;
a second tri-stack layer comprising HfO 2 ; and
a third tri-stack layer comprising Al 2 O 3 .
10. The method of claim 8 ,
wherein the second tri-stack layer comprising HfO 2 is disposed over the first tri-stack layer comprising Al 2 O 3 , and
wherein the third tri-stack layer comprising Al 2 O 3 is disposed over the second tri-stack layer comprising HfO 2 .