Efficient metal-insulator-metal capacitor

Abstract

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.

Description

BACKGROUNDTechnical Field[0001]The present invention generally relates to capacitor fabrication and, more particularly, to improved processes for fabricating metal-insulator-metal capacitors that use self-assembling block copolymers to increase capacitance per unit area without increasing the number of photomasks needed.Description of the Related Art[0002]Metal-insulator-metal capacitors are used throughout circuit designs to provide integrated capacitors that can be formed during semiconductor fabrication processes instead of using discrete capacitors on circuit board. However, to increase the capacitance per unit area, additional steps are needed to change the topography of the device. In particular, additional mask steps are often used to provide patterning. These additional mask steps increase process complexity, and hence fabrication costs, as well as potential plasma damage at the interface between metal and dielectric layers.SUMMARY[0003]A method for forming a capacitor inclu...

AI Technical Summary

Benefits of technology

The patent describes a method for making capacitors on a substrate using a patterned self-assembled material. Another method involves using two masks to create cavities in the substrate and form a capacitor stack on both horizontal and vertical surfaces of the substrate. A further method involves using a single mask and a specific lithographic pattern to create the capacitor area. The resulting capacitor stack includes a first metallic layer, an insulator layer, and a second metallic layer. A cap layer and a hardmask layer are also included in the structure. These methods may provide more precise and efficient ways to make capacitors on a substrate.

Problems solved by technology

These additional mask steps increase process complexity, and hence fabrication costs, as well as potential plasma damage at the interface between metal and dielectric layers.

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