Partial Directional Etch Method and Resulting Structures
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorShiang-Bau Wang
Life of this patent
Estimating the term…
Abstract
In a gate replacement process, forming a dummy gate and an adjacent structure; In a gate replacement process, a dummy gate and adjacent structure, such as a source/drain region, are formed. The dummy gate is removed, at least in part, using a directional etch to remove some but not all of the dummy gate to form a trench. A portion of the dummy gate remains and protects the adjacent structure. A gate electrode can then be formed in the trench. A two step process can be employed, using an initial isotropic etch followed by the directional etch.
Claims20
A method comprising:
- forming a dummy gate and an adjacent structure;
- using a directional etch, removing some but not all of the dummy gate to form a trench, wherein a portion of the dummy gate remains and protects the adjacent structure;
- and
- forming a gate electrode in the trench.
A method comprising:
- forming a fin extending from a semiconductor substrate;
- depositing over the fin a dummy gate material;
- patterning the dummy gate material to form a dummy gate extending over a top of the fin and along sidewalls of the fin;
- depositing a spacer material on the dummy gate and patterning the spacer material to form spacers on respective sidewalls of the dummy gate;
- using the dummy gate and spacers as a mask, etching portions of the fin to form fin recesses;
- filling respective fin recesses with source/drain regions;
- depositing a dielectric layer to surround the dummy gate, the source/drain regions, and the fin;
- isotropically etching the dummy gate to remove a top portion of the dummy gate and to leave a bottom portion of the dummy gate;
- anisotropically etching the bottom portion of the dummy gate to partially remove the bottom portion of the dummy gate and to leave a remnant portion of the dummy gate;
- and
- forming on the remnant portion of the dummy gate a metal gate electrode.
A device comprising:
- a fin extending upwards from a substrate;
- an isolation material formed over the fin;
- a gate, including a gate dielectric, within a trench in the isolation material, the gate extending over a top and sidewalls of the fin;
- and
- a polysilicon material extending along a bottom portion of the trench, the polysilicon material being interjacent the gate dielectric and the substrate.
Dependencies are inferred from the claim text.