Asymmetric high-k dielectric for reducing gate induced drain leakage
View Patent ↗An asymmetric high-k dielectric for reduced gate induced drain leakage in high-k MOSFETs and methods of manufacture are disclosed. The method includes performing an implant process on a high-k dielectric sidewall of a gate structure. The method further includes performing an oxygen annealing process to grow an oxide region on a drain side of the gate structure, while inhibiting oxide growth on a source side of the gate structure adjacent to a source region.
1. A structure, comprising:
a gate structure comprising an asymmetrically thick gate dielectric which is thicker on a drain side of the gate structure than a source side of the gate structure, wherein the asymmetrically thick gate dielectric is composed of a regrowth of dielectric material on the drain side to form the thicker drain side of the gate structure;
a damaged spacer material on the drain side of the gate structure along a sidewall of the gate structure; and
a non-damaged spacer material on the source side of the gate structure along another sidewall of the gate structure.
2. The structure of claim 1 , wherein the asymmetrically thick gate dielectric is comprised of an oxide material.
3. The structure of claim 2 , wherein the oxide material is a high-k oxide material.
4. The structure of claim 3 , wherein the high-k oxide material is HfO 2 .
5. The structure of claim 4 , wherein the gate structure comprises a gate material on the asymmetrically thick gate dielectric.
6. The structure of claim 5 , wherein the gate material is formed on the HfO 2 .
7. The structure of claim 6 , wherein the asymmetrically thick gate dielectric includes an interfacial dielectric layer of fin material under the HfO 2 .
8. The structure of claim 7 , wherein the interfacial dielectric layer comprises nitrogen.
9. The structure of claim 8 , wherein the interfacial dielectric layer has a first thickness on the source side of the gate structure and a second thickness on the drain side of the gate structure, the first thickness being different than the second thickness.
10. The structure of claim 9 , wherein the second thickness on the drain side of the gate structure is thicker than the first thickness on the source side of the gate structure.
11. The structure of claim 1 , wherein the gate structure is a short channel gate structure.
12. The structure of claim 1 , wherein the damaged spacer material comprises Si 3 N 4 .
13. The structure of claim 1 , wherein the gate structure further comprises sidewalls on the source side of the gate structure and the drain side of the gate structure.