Metal gate structure
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsPeng-Soon Lim, Da-Yuan Lee, Kuang-Yuan Hsu
Life of this patent
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Abstract
A method includes forming a trench over a substrate, wherein the trench is surrounded by gate spacers and an inter-layer dielectric layer, depositing a dielectric layer on a bottom and along sidewalls of the trench, depositing a metal layer over the dielectric layer, depositing a protection layer over the metal layer, wherein the protection layer has an uneven thickness, applying an etch-back process to the protection layer and the metal layer, wherein as a result of applying the etch-back process, a portion of the metal layer has been removed and at least a portion of the protection layer remains at the bottom of the trench and removing the protection layer from the trench.
Claims20
A method comprising:
- forming a trench over a substrate, wherein the trench is surrounded by gate spacers and an inter-layer dielectric layer;
- depositing a dielectric layer on a bottom and along sidewalls of the trench;
- depositing a metal layer over the dielectric layer;
- depositing a protection layer over the metal layer, wherein the protection layer has an uneven thickness;
- applying an etch-back process to the protection layer and the metal layer, wherein as a result of applying the etch-back process, a portion of the metal layer has been removed and at least a portion of the protection layer remains at the bottom of the trench;
- and
- removing the protection layer from the trench.
A method comprising:
- forming a trench over a substrate, wherein the trench is surrounded by gate spacers and an inter-layer dielectric layer;
- depositing a dielectric layer on a bottom and along sidewalls of the trench;
- depositing a metal layer over the dielectric layer;
- depositing a protection layer over the metal layer, wherein a surface of a portion of the protection layer in the trench and along the sidewalls is of a gradual slope;
- applying an etching process to the protection layer and a portion of the metal layer adjacent to the portion of the protection layer, wherein after applying the etching process, a bottom portion of the protection layer remains at the bottom of the trench;
- and
- removing the bottom portion of the protection layer from the trench.
A method comprising:
- depositing a dielectric layer on a bottom and along sidewalls of a trench;
- depositing a metal layer over the dielectric layer;
- depositing a protection layer over the metal layer;
- applying an etch-back process to the protection layer and the metal layer, wherein as a result of applying the etch-back process, a portion of the metal layer has been removed and at least a portion of the protection layer remains at the bottom of the trench;
- and
- removing the protection layer from the trench, wherein after removing the protection layer from the trench, the metal layer comprises a metal sidewall, a metal bottom, a corner portion between the metal sidewall and the metal bottom, wherein the corner portion comprises a step and a non-vertical slope.
Dependencies are inferred from the claim text.