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 method comprising:
forming a gate first structure on a substrate on a gate dielectric material;
forming spacers on the gate first structure;
performing an angled implant on a source side of the gate first structure after spacer formation and after forming a mask on a drain side of the gate first structure to damage a region of the spacer on the source side only; and
performing a regrowth of oxygen on the drain side of the gate first structure to thicken a dielectric layer on the drain side of the gate first structure.
2. The method of claim 1 , wherein the damaged region on the source side is removed using etching processes, selective to the damaged region.
3. The method of claim 2 , further comprising forming a second spacer on exposed portions of the gate dielectric material, material of the gate first structure and spacer material remaining on the drain side.
4. The method of claim 3 , wherein the second spacer is a nitride material.
5. The method of claim 4 , further comprising removing horizontal surfaces of the spacer materials of the spacers and second spacer, and a cap material on the gate first structure.
6. The method of claim 5 , further comprising removing of the spacer material covering the gate dielectric material, formed on the drain side.
7. The method of claim 6 , wherein the growth process is a low temperature anneal process which forms a regrowth of oxygen on the drain side, while sidewalls on the source side will prevent or inhibit O 2 ingress during the anneal process.