Capacitors including inner and outer electrodes

Abstract

Provided are capacitor stacks for use in integrated circuits and methods of fabricating these stacks. A capacitor stack includes a dielectric layer and one or two inner electrode layers, such as a positive inner electrode layer and a negative inner electrode layer. The inner electrode layers directly interface the dielectric layer. The stack may also include outer electrode layers. The inner electrode layers are either chemically stable or weakly chemically unstable, while in contact with the dielectric layer based on the respective phase diagrams. Furthermore, the electron affinity of the positive inner electrode layer may be less than the electron affinity of the dielectric layer. The sum of the electron affinity and bandgap of the negative inner electrode layer may be less than that of the dielectric layer. In some embodiments, inner electrode layers are formed from heavily doped semiconducting materials, such as gallium arsenide or gallium aluminum arsenide.