Molybdenum oxide top electrode for DRAM capacitors

摘要

A metal oxide bilayer second electrode for a MIM DRAM capacitor is formed wherein the layer of the electrode that is in contact with the dielectric layer (i.e. bottom layer) has a desired composition and crystal structure. An example is crystalline MoO2 if the dielectric layer is TiO2 in the rutile phase. The other component of the bilayer (i.e. top layer) is a sub-oxide of the same material as the bottom layer. The top layer serves to protect the bottom layer from oxidation during subsequent PMA or other DRAM fabrication steps by reacting with any oxygen species before they can reach the bottom layer of the bilayer second electrode.

主权项

1. A method for forming a capacitor stack, the method comprising:
forming a first electrode layer on a substrate; forming a dielectric layer on the first electrode layer; and forming a second electrode layer on the dielectric layer,
wherein forming the second electrode layer comprises forming a bottom layer on the dielectric layer and forming a top layer on the bottom layer,wherein the bottom layer comprises MoO2 and wherein the top layer comprises a sub-oxide of MoO2.