Barrier layers and aluminum contacts
AssigneeApplied Materials, Inc.
InventorsKenny K. Ngan, Edith Ong
Life of this patent
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Abstract
In the manufacture of high temperature deposited aluminum contacts onto silicon substrates wherein a barrier layer of titanium nitride is used, the improvement wherein the titanium nitride contains oxygen. The improved contacts are made by depositing a titanium-containing layer onto a silicon substrate, performing a first, high temperature nitrogen anneal in vacuum to form a low resistance TiSi.sub.x contact to the silicon, and performing a second, lower temperature anneal in vacuum using a mixture of nitrogen and oxygen to add oxygen to the titanium nitride layer. This oxygen-containing titanium nitride layer provides an improved barrier to a subsequently deposited high temperature deposited aluminum layer.
Claims16
A method of forming a titanium nitride barrier layer which comprises the following steps in sequence
- a) depositing a titanium-containing layer on a substrate in a vacuum environment;
- b) annealing said layer in nitrogen under vacuum at a temperature of from about 750.degree.-850.degree. C.;
- and
- c) annealing said layer in nitrogen containing from about 3-15% by volume of oxygen under vacuum at a temperature of from about 500.degree.-550.degree. C. without removing the substrate from vacuum.
A method of forming an aluminum contact on a silicon substrate comprising the following steps in sequence:
- a) sputter depositing a titanium-containing layer over said silicon under vacuum;
- b) annealing said titanium-containing layer in nitrogen under vacuum at a temperature of from about 750.degree.-850.degree. C., thereby forming a titanium silicide interface;
- c) annealing said titanium-containing layer under nitrogen containing from about 3-15% by volume of oxygen under vacuum at a temperature of from about 500.degree.-550.degree. C., thereby forming an oxygen-containing titanium nitride layer without removing the substrate from vacuum;
- and
- d) sputter depositing an aluminum layer over the stuffed titanium nitride layer at a temperature of over about 400.degree. C.
Dependencies are inferred from the claim text.