Method for forming a metal extrusion free via
AssigneeTexas Instruments Incorporated
InventorsAlfred J. Griffin, Jr., Antonietta Oliva, Adel El Sayed
Life of this patent
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Abstract
A process whereby elimination of metal extrusion through the via-barrier layer into the base of etched via holes is accomplished by controlling the process temperature of the via-barrier deposition to less than 400° C., and preferably to about 380° C. By eliminating the cause of metal extrusions, i.e., excessive thermally induced stresses on the metal confined biaxially by the dielectric via walls, the resulting defect-free vias are independent of the barrier thickness. The method is applicable to different metal stacks, and in turn, yield and reliability of the device is significantly enhanced.
Claims2
A method for making a multilevel integrated circuit device free of metal extrusions into a via including the steps of:
- providing a semiconductor substrate having a dielectric layer,
- depositing a metal stack including a conductive layer of an aluminum alloy sandwiched between layers of titanium, and titanium nitride in various combinations thereof, patterning and etching to form interconnection lines,
- depositing one or more dielectric layers, patterning and etching the dielectric to form a via hole to contact an interconnection line,
- depositing a seed layer and a via-barrier layer at a controlled temperature, low enough to substantially eliminate deformation on the metal interconnection line, and
- filling the via hole with a metal plug.
A method for making a multilevel integrated circuit device free of metal extrusions into a via including the steps of:
- providing a semiconductor substrate having a dielectric layer,
- depositing a metal stack including reacted titanium aluminide,
- patterning and etching to form interconnection lines,
- depositing one or more dielectric layers, patterning and etching the dielectric to form a via hole to contact an interconnection line,
- depositing a seed layer and a via-barrier layer at a controlled temperature, low enough to substantially eliminate deformation on the metal interconnection line, and
- filling the via hole with a metal plug.
Dependencies are inferred from the claim text.