Method for fabricating a seed layer
AssigneeASM International N.V.
InventorsMiika Leinikka, Juhana J. T. Kostamo
Life of this patent
Estimating the term…
Abstract
The present invention produces a seed layer for the deposition of copper for metallizing integrated circuits. A diffusion barrier is deposited upon the wafer. In one embodiment of the invention, a metal oxide layer is then formed on the diffusion barrier. The oxidized metal is then reduced to a conductive lower oxidation state or to its elemental form. That metal is then used as the seed layer for the growth of copper. In another embodiment, the surface of the barrier layer is repeatedly oxidized and reduced in order to reduce incubation time for the growth of a seed layer. A ruthenium seed layer is then deposited over the treated barrier layer.
Claims48
A method for metallizing an integrated circuit, the method comprising
- depositing a diffusion barrier on a substrate;
- oxidizing a top layer of the diffusion barrier to form a metal oxide layer, wherein the oxidizing forms the metal oxide layer from metal in the diffusion barrier;
- reducing the oxidation state of the metal oxide layer formed by oxidizing the top layer of the diffusion barrier to form a first seed layer;
- and
- depositing a conductor directly on the first seed layer.
A method for metallizing an integrated circuit, the method comprising
- forming a diffusion barrier layer on a substrate;
- performing a preparation process on the substrate to form a nucleation layer, the preparation process comprising exposing the diffusion barrier layer to an oxidant and a reducing agent, wherein the oxidant oxidizes a portion of the diffusion barrier layer and the reducing agent reduces the oxidized portion of the diffusion barrier layer;
- depositing a conductor over the nucleation layer to form a seed layer that is different from the nucleation layer after the preparation process is complete;
- and
- depositing copper over the seed layer.
Dependencies are inferred from the claim text.