Protection of high-k dielectric during reliability anneal on nanosheet structures
AssigneeInternational Business Machines Corporation
InventorsNicolas J. Loubet, Sanjay C. Mehta, Vijay Narayanan, Muthumanickam Sankarapandian
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Abstract
A starting structure for forming a gate-all-around field effect transistor (FET) and a method of fabricating the gate-all-around FET. The method includes forming a stack of silicon nanosheets above a substrateforming an interfacial layer over the nanosheets depositing a high-k dielectric layer conformally on the interfacial layer. The method also includes depositing a layer of silicon nitride (SiN) above the high-k dielectric layer and performing reliability anneal after depositing the layer of SiN to crystallize the high-k dielectric layer.
Claims20
A method of fabricating a gate-all-around field effect transistor (FET), the method comprising:
- forming a stack of silicon nanosheets above a substrate, the nanosheets being formed as three-dimensional structures with empty spaces around each of the nanosheets;
- forming an interfacial layer over the nanosheets, the forming the interfacial layer including covering four sides that form a perimeter of a cross-section of the three-dimensional structure of each of the nanosheets;
- depositing a high-k dielectric layer conformally on the interfacial layer;
- depositing a layer of silicon nitride (SiN) above the high-k dielectric layer;
- and
- performing reliability anneal after the depositing the layer of SiN to crystalize the high-k dielectric layer.
A starting structure for performing reliability anneal on a high-k dielectric layer during the formation of a gate-all-around field effect transistor (FET), the structure comprising:
- a stack of nanosheets formed above a substrate, the nanosheets being comprised of silicon and being formed as three-dimensional structures with empty spaces around each of the nanosheets;
- an interfacial layer formed over the nanosheets, the interfacial layer covering four sides that form a perimeter of a cross-section of the three-dimensional structure of each of the nanosheets;
- a high-k dielectric layer conformally formed on the interfacial layer;
- and
- a silicon nitride (SiN) layer formed above the high-k dielectric layer.
Dependencies are inferred from the claim text.