Conformal nitridation of one or more fin-type transistor layers
Fin-type transistor fabrication methods and structures are provided having one or more nitrided conformal layers, to improve reliability of the semiconductor device. The method includes, for example, providing at least one material layer disposed, in part, conformally over a fin extending above a substrate, the material layer(s) including a gate dielectric layer; and performing a conformal nitridation process over an exposed surface of the material layer(s), the conformal nitridation process forming an exposed, conformal nitrided surface.
1. A structure comprising:
a fin-type transistor structure, the fin-type transistor structure comprising:
a gate dielectric layer comprising an oxide material disposed, at least in part, conformally over an interfacial layer that is disposed conformally over a fin of the fin-type transistor, the fin extending above a substrate, wherein an outer surface of the gate dielectric layer is an oxynitrided surface of the gate dielectric layer,
wherein the oxynitrided surface of the gate dielectric layer comprises an increased concentration of nitrogen as compared to an underlying portion of the gate dielectric layer,
wherein the gate dielectric layer comprises an oxynitrided region in an upper portion of the gate dielectric layer extending from the oxynitrided surface that comprises an increased concentration of nitrogen as compared to an underlying portion of the gate dielectric layer, and
wherein the underlying portion of the gate dielectric layer and the interfacial layers are free of oxygen voids.
2. The structure of claim 1 , wherein the oxynitrided region of the gate dielectric layer includes nitrogen diffused from the oxynitrided surface of the gate dielectric layer.
3. The structure of claim 1 , wherein the fin-type transistor structure further comprises a capping layer disposed conformally over the oxynitrided surface of the gate dielectric layer.
4. The structure of claim 3 , wherein the capping layer comprises a nitride material.
5. The structure of claim 3 , wherein an outer surface of the capping layer is a nitrided surface of the capping layer comprising an increased concentration of nitrogen as compared to an underlying portion of the capping layer.
6. The structure of claim 5 , wherein the capping layer comprises a nitrided region in an upper portion of the capping layer extending from the nitrided surface that comprises an increased concentration of nitrogen as compared to an underlying portion of the capping layer.
7. The structure of claim 6 , wherein the nitrided region of the capping layer includes nitrogen diffused from the nitrided surface of the capping layer.
8. The structure of claim 6 , wherein the gate dielectric layer comprises an oxynitrided region in an upper portion of the gate dielectric layer extending from the oxynitrided surface that comprises an increased concentration of nitrogen as compared to an underlying portion of the gate dielectric layer.
9. The structure of claim 5 , wherein the nitrided surface of the capping layer seals at least one of carbon and fluorine within the gate dielectric layer capping layer.
10. The structure of claim 1 , wherein the interfacial layer comprises silicon oxide.
11. The structure of claim 1 , wherein the oxynitrided surface of the gate dielectric layer seals and stabilizes oxygen contents disposed within the gate dielectric layer.
12. The structure of claim 1 , wherein the gate dielectric layer is disposed, at least in part, conformally over a plurality of fins of the fin-type transistor extending above the substrate.
13. The structure of claim 1 , further comprising a plurality of gates disposed over the upper portions of the fins.