Capacitor structure with metal bilayer and method for using the same

摘要

A method for using a metal bilayer is disclosed. First, a bottom electrode is provided. Second, a dielectric layer which is disposed on and is in direct contact with the lower electrode is provided. Then, a metal bilayer which serves as a top electrode in a capacitor is provided. The metal bilayer is disposed on and is in direct contact with the dielectric layer. The metal bilayer consists of a noble metal in direct contact with the dielectric layer and a metal nitride in direct contact with the noble metal.

主权项

1. A capacitor structure, comprising:
an upper electrode substantially consisting of a single noble metal having a first thickness; a cap layer substantially consisting of a metal nitride and directly covering said upper electrode, wherein the upper electrode and the cap layer together act as a working top electrode of the capacitor structure, wherein the cap layer has a second thickness, and wherein the first thickness is to avoid an increase of equivalent oxide thickness (EOT), and the second thickness is to not dominate electronic properties of the working top electrode; a lower electrode comprising a conductive material, wherein said cap layer is not simultaneously in direct contact with said upper electrode and with said lower electrode; and a dielectric layer disposed between and in direct contact with said upper electrode and said lower electrode, wherein the dielectric layer consists of oxides or oxynitrides of Si, Ge, or Al.