Efficient metal-insulator-metal capacitor
Capacitors include a stack that has a first metallic layer formed over a substrate with at least one high domain and at least one low domain, an insulator formed over the first metallic layer, and a second metallic layer formed over the insulator. A bottom contact is formed in the substrate having a top surface that is even with a top surface of the substrate in the at least one high domain. A cap layer is formed directly on the substrate in the high domains, under the stack.
1. A capacitor, comprising:
a stack, comprising:
a first metallic layer formed over a substrate that comprises at least one high domain and at least one low domain, where a surface of the substrate in the at least one low domain has a height that is lower than a surface of the substrate in the at least one high domain;
an insulator formed over the first metallic layer; and
a second metallic layer formed over the insulator;
a bottom contact formed in the substrate having a top surface that is even with a top surface of the substrate in the at least one high domain; and
a cap layer formed directly on the substrate in the high domains, under the stack.
2. The capacitor of claim 1 , wherein the cap layer is absent over the low domains.
3. The capacitor of claim 1 , further comprising:
a protective layer formed over the stack; and
a dielectric layer formed over and around the protective layer and the stack.
4. The capacitor of claim 3 , further comprising a top contact that penetrates the dielectric layer and the protective layer to form an electrical contact with the top metallic layer.
5. The capacitor of claim 1 , wherein the first metallic layer has low domain with a bottom surface that is lower than a bottom surface of the bottom contact.
6. The capacitor of claim 1 , wherein the second metallic layer comprises a single-walled downward extension above a low domain.
7. The capacitor of claim 1 , wherein the first metallic region comprises a plurality of low regions, including a low region over the bottom contact and at least one additional low region.
8. A capacitor, comprising:
a stack, comprising:
a first metallic layer formed over a substrate that comprises at least one high domain and a plurality of low domains, where a surface of the substrate in the at least one low domain has a height that is lower than a surface of the substrate in the at least one high domain;
an insulator formed over the first metallic layer; and
a second metallic layer formed over the insulator;
a bottom contact formed in the substrate under a first low domain of the first metallic layer, having a top surface that is even with a top surface of the substrate in the at least one high domain; and
a cap layer formed directly on the substrate in the high domains, under the stack.
9. The capacitor of claim 8 , wherein the cap layer is absent over the low domains.
10. The capacitor of claim 8 , further comprising:
a protective layer formed over the stack; and
a dielectric layer formed over and around the protective layer and the stack.
11. The capacitor of claim 10 , further comprising a top contact that penetrates the dielectric layer and the protective layer to form an electrical contact with the top metallic layer.
12. The capacitor of claim 8 , wherein the first metallic layer has low domain with a bottom surface that is lower than a bottom surface of the bottom contact.
13. The capacitor of claim 8 , wherein the second metallic layer comprises a single-walled downward extension above a low domain.
14. A capacitor, comprising:
a stack, comprising:
a first metallic layer formed over a substrate that comprises at least one high domain and at least one low domain, where a surface of the substrate in the at least one low domain has a height that is lower than a surface of the substrate in the at least one high domain;
an insulator formed over the first metallic layer; and
a second metallic layer formed over the insulator;
a bottom contact formed in the substrate in electrical contact with the first metallic layer, having a top surface that is even with a top surface of the substrate in the at least one high domain;
a cap layer formed directly on the substrate in the high domains, under the stack;
a protective layer formed over the stack;
a dielectric layer formed over and around the protective layer and the stack; and
a top contact that penetrates the dielectric layer and the protective layer to form an electrical contact with the top metallic layer.
15. The capacitor of claim 14 , wherein the cap layer is absent over the low domains.
16. The capacitor of claim 14 , wherein the first metallic layer has low domain with a bottom surface that is lower than a bottom surface of the bottom contact.
17. The capacitor of claim 14 , wherein the second metallic layer comprises a single-walled downward extension above a low domain.