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US 7,442,638 B2Granted
Method for forming a tungsten interconnect structure with enhanced sidewall coverage of the barrier layer
AssigneeAdvanced Micro Devices, Inc.
InventorsKai Frohberg, Katja Huy, Volker Kahlert
Life of this patent
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Abstract
By performing a re-sputter process during the formation of a barrier layer for a contact opening in a tungsten-based process, the reliability of the tungsten deposition, as well as the performance of the resulting contact plug, may be enhanced. During the re-sputtering process, a thickness of the titanium-based barrier layer may be reduced at the contact bottom, while at the same time the material is re-condensed on critical lower sidewall portions of the contact opening.
Claims16
A method, comprising:
- forming a contact opening in an interlayer dielectric material so as to connect to a contact region of a circuit element;
- depositing a titanium-based barrier layer in said contact opening by forming a titanium layer followed by a titanium nitride layer by sputter deposition;
- redistributing a portion of said titanium nitride layer and said titanium layer from said titanium-based barrier layer from a bottom of said contact opening to a lower sidewall portion by directed sputtering on the basis of an inert species;
- and
- sputter depositing a final portion of titanium nitride for a time period that is shorter than a preceding deposition time.
2 more elements
A method, comprising:
- forming a conductive barrier layer in a contact opening by sputter deposition by forming a first layer followed by a second layer of a different composition;
- re-sputtering a portion of said first layer and said second layer of said conductive barrier layer from a bottom of said contact opening to sidewalls thereof;
- sputter depositing a final portion of said conductive barrier layer for a time period that is shorter than a preceding deposition time;
- and
- filling said contact opening with a tungsten-containing material.
2 more elements
Dependencies are inferred from the claim text.