High work function, manufacturable top electrode

摘要

Provided are MIM DRAM capacitors and methods of forming thereof. A MIM DRAM capacitor may include an electrode layer formed from a high work function material (e.g., greater than about 5.0 eV). This layer may be used to reduce the leakage current through the capacitor. The capacitor may also include another electrode layer having a high conductivity base portion and a conductive metal oxide portion. The conductive metal oxide portion serves to promote the growth of the high k phase of the dielectric layer.

主权项

1. A method for forming a capacitor stack comprising:
forming a first electrode layer,
wherein forming the first electrode layer comprises:
forming a first layer above a substrate,
wherein the first layer comprises a conductive metal nitride,wherein the first layer has a thickness of between 20 A and 150 A, andforming a second layer above the first layer,
wherein the second layer comprises molybdenum oxide having a distorted rutile structure; forming a third layer above the second layer,
wherein the third layer is a dielectric layer; and forming a second electrode layer above the third layer,
wherein forming the second electrode layer comprises:
forming a fourth layer,
wherein the fourth layer comprises nickel oxide, andforming a fifth layer above the fourth layer,
wherein the fifth layer comprises a conductive metal nitride.