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US 7,741,230 B2Granted
Highly-selective metal etchants
AssigneeIntel Corporation
InventorsWilly Rachmady, Jack T. Kavalieros, Mark Y. Liu, Mark L. Doczy
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Abstract
A highly selective metal wet etchant with an active ingredient comprising one or more types of molecules having two or more oxygen atoms is described. In one embodiment, the wet etchant is utilized to pattern a metal layer in a semiconductor structure. In another embodiment, a highly selective metal wet etchant with an active ingredient comprising one or more types of molecules having two or more oxygen atoms is used to pattern a metal gate electrode in a replacement gate processing scheme.
Claims30
A method for making a semiconductor structure comprising:
- forming a dielectric layer above a substrate;
- forming a metal layer above said dielectric layer;
- forming a masking layer above said metal layer, wherein said masking layer is comprised of a photo-resist;
- patterning said masking layer to provide a patterned masking layer and an exposed portion of said metal layer;
- and
- removing, in the presence of said patterned masking layer, said exposed portion of said metal layer with a wet etch solution, wherein said wet etch solution is comprised of an active ingredient comprising one or more types of molecules having two or more oxygen atoms, wherein said exposed portion of said metal layer is removed with a first selectivity to said photo-resist, and wherein said exposed portion of said metal layer is removed with a second selectivity to said dielectric layer.
3 more elements
A method for making a semiconductor structure comprising:
- forming a first dielectric layer above a substrate;
- forming a trench in said first dielectric layer to provide an exposed portion of said substrate;
- forming a second dielectric layer above said exposed portion of said substrate;
- forming a metal layer above said second dielectric layer;
- forming a masking layer above said metal layer, wherein said masking layer is comprised of a photo-resist;
- patterning said masking layer to provide an exposed portion of said metal layer within said trench and to provide a covered portion of said metal layer within said trench;
- and
- removing said exposed portion of said metal layer within said trench with a wet etch solution, wherein said wet etch solution is comprised of an active ingredient comprising one or more types of molecules having two or more oxygen atoms, wherein said exposed portion of said metal layer within said trench is removed with a first selectivity to said photo-resist, and wherein said exposed portion of said metal layer within said trench is removed with a second selectivity to said second dielectric layer.
5 more elements
A method for making a semiconductor device comprising:
- forming a gate placeholder structure above a substrate;
- forming source/drain regions in said substrate and on either side of said gate placeholder;
- forming a dielectric layer above said substrate and above said gate placeholder structure;
- planarizing said dielectric layer to expose the top surface of said gate placeholder structure;
- removing said gate placeholder structure to provide a trench in said dielectric layer and to provide an exposed portion of said substrate within said trench;
- forming a gate dielectric layer above said exposed portion of said substrate within said trench;
- forming a first metal gate electrode above said gate dielectric layer;
- forming a masking layer above said first metal gate electrode, wherein said masking layer is comprised of a photo-resist;
- patterning said masking layer to provide an exposed portion of said first metal gate electrode within said trench and to provide a covered portion of said first metal gate electrode within said trench;
- and
- removing said exposed portion of said first metal gate electrode within said trench with a wet etch solution to provide an exposed portion of said gate dielectric layer within said trench, wherein said wet etch solution is comprised of an active ingredient comprising one or more types of molecules having two or more oxygen atoms, wherein said exposed portion of said first metal gate electrode within said trench is removed with a first selectivity to said photo-resist, and wherein said exposed portion of said first metal gate electrode within said trench is removed with a second selectivity to said gate dielectric layer;
- removing said masking layer;
- and
- forming a second metal gate electrode within said trench, wherein said second metal gate electrode is above said first metal gate electrode and above said exposed portion of said gate dielectric layer within said trench.
11 more elements
Dependencies are inferred from the claim text.