Efficient metal-insulator-metal capacitor
Capacitors and methods of forming the same include forming a self-assembled pattern of periodic first and second domains using first and second block copolymer materials over a substrate. The second block copolymer material is etched away. Material from the substrate is etched based on a pattern defined by the first block copolymer material to form cavities in the substrate. A capacitor stack is conformally deposited over the substrate, such that the capacitor stack is formed on horizontal surfaces of the substrate and vertical surfaces of the cavities.
1. A capacitor, comprising:
a stack, comprising:
a first metallic layer conformally formed over a substrate that comprises at least one high domain and at least one low domain;
an insulator conformally formed over the first metallic layer; and
a second metallic layer conformally 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 that is in electrical contact with the first metallic layer;
a cap layer formed directly on the substrate in the high domains, under the stack; and
a hardmask layer formed directly on the cap layer in the high domains, under the stack.
2. The capacitor of claim 1 , wherein the cap layer and the hardmask layer are absent over the low domains.
3. The capacitor of claim 1 , wherein a surface of the substrate in the low domains has a height that is lower than a surface of the substrate in the high domains.
4. 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.
5. The capacitor of claim 4 , further comprising a top contact that penetrates the dielectric layer and the protective layer to form an electrical contact with the second metallic layer.