Methods of forming capacitors 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.