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US 7,888,263 B2Granted
Cladded silver and silver alloy metallization for improved adhesion electromigration resistance
AssigneeArizona Board of Regents
InventorsTerry L. Alford, Ekta Misra
Life of this patent
Estimating the term…
Abstract
In semiconductor integrated circuit and device fabrication interconnect metallization is accomplished by a clad Ag deposited on a SiO2 level on a Si surface. The clad Ag has a layer of an alloy of Ag and Al (5 atomic %) contacting the SiO2, a layer of substantially pure Ag and an outer layer of the Ag and Al alloy. The alloy improves adhesion to the SiO2, avoids agglomeration of the Ag, reduces or eliminates diffusion at the SiO2 surface, reduces electromigration and presents a passive exterior surface.
Claims22
An apparatus comprising:
- a dielectric layer;
- and
- a conductive interconnect including:
- a first silver (Ag)-aluminum (Al) alloy layer disposed on the dielectric layer, wherein the first Ag—Al alloy layer comprises Al in a range from 0.5 atomic % to 5 atomic %;
- a Ag layer disposed on and in direct contact with the first Ag—Al alloy layer, wherein the first Ag—Al alloy layer is disposed between the Ag layer and the dielectric layer;
- and
- a second Ag—Al alloy layer disposed on and in direct contact with the Ag layer, wherein the Ag layer is disposed between the second Ag—Al alloy layer and the first Ag—Al alloy layer.
4 more elements
A method comprising:
- forming a first silver (Ag)-aluminum (Al) alloy layer on a dielectric layer, wherein the first Ag—Al alloy layer includes Al in a range from 0.5 atomic % to 5 atomic %;
- and
- forming a Ag layer on and in direct contact with the first Ag—Al alloy layer, wherein the first Ag—Al alloy layer is disposed between the Ag layer and the dielectric layer;
- and
- forming a second Ag—Al alloy layer on and in direct contact with the Ag layer, wherein the Ag layer is disposed between the second Ag—Al alloy layer and the first Ag—Al layer.
2 more elements
Dependencies are inferred from the claim text.