Abstract: A semiconductor device includes a semiconductor substrate, a pair of source/drain regions, and a gate stack. The pair of source/drain regions is on the semiconductor substrate. The gate stack is laterally between the source/drain regions and includes a gate dielectric layer over the semiconductor fin, a metal element-containing layer over the gate dielectric layer, and a fill metal layer over the metal element-containing layer. The metal element-containing layer has a dopant, and a concentration of the dopant in an upper portion of the metal element-containing layer is higher than a concentration of the dopant in a bottom portion of the metal element-containing layer.

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.

Abstract: A method includes forming in sequence a metallic capping layer and a dummy gate electrode layer over a semiconductor substrate; patterning the metallic capping layer and the dummy gate electrode layer to form a first stacked structure including a first portion of the metallic capping layer and a first portion of the dummy gate electrode layer; forming a plurality of first gate spacers on opposite sides of the first stacked structure; removing the first portion of the dummy gate electrode layer to expose the first portion of the metallic capping layer; and forming a first work function metal layer on the first portion of the metallic capping layer.

Abstract: A method includes forming a gate dielectric layer over a semiconductor substrate, forming a first metal element-containing layer over the gate dielectric layer, and thermal soaking the first metal element-containing layer in a first gas, such that a constituent of the first gas is diffused into the first metal element-containing layer.

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.

Abstract: A method includes forming a dummy gate stack, forming a dielectric layer, with the dummy gate stack located in the dielectric layer, removing the dummy gate stack to form a opening in the dielectric layer, forming a metal layer extending into the opening, and etching back the metal layer. The remaining portions of the metal layer in the opening have edges lower than a top surface of the dielectric layer. A conductive layer is selectively deposited in the opening. The conductive layer is over the metal layer, and the metal layer and the conductive layer in combination form a replacement gate.

Abstract: A method includes forming in sequence a metallic capping layer and a dummy gate electrode layer over a semiconductor substrate; patterning the metallic capping layer and the dummy gate electrode layer to form a first stacked structure including a first portion of the metallic capping layer and a first portion of the dummy gate electrode layer; forming a plurality of first gate spacers on opposite sides of the first stacked structure; removing the first portion of the dummy gate electrode layer to expose the first portion of the metallic capping layer; and forming a first work function metal layer on the first portion of the metallic capping layer.

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.

Abstract: A method includes forming a gate dielectric layer over a semiconductor substrate, forming a first metal element-containing layer over the gate dielectric layer, and thermal soaking the first metal element-containing layer in a first gas, such that a constituent of the first gas is diffused into the first metal element-containing layer.

Abstract: A semiconductor device includes a semiconductor substrate having a channel region. A gate dielectric layer is over the channel region of the semiconductor substrate. A work function metal layer is over the gate dielectric layer. The work function metal layer has a bottom portion, an upper portion, and a work function material. The bottom portion is between the gate dielectric layer and the upper portion. The bottom portion has a first concentration of the work function material, the upper portion has a second concentration of the work function material, and the first concentration is higher than the second concentration. A gate electrode is over the upper portion of the work function metal layer.

Abstract: A device comprises a metal gate structure over a substrate, wherein the metal gate structure comprises a first metal sidewall, a metal bottom layer, a first corner portion between the first metal sidewall and the metal bottom layer, wherein the first corner portion comprises a first step and a first ramp, a second metal sidewall and a second corner portion between the second metal sidewall and the metal bottom layer, wherein the second corner portion comprises a second step and a second ramp.

Abstract: A device comprises a metal gate structure over a substrate, wherein the metal gate structure comprises a first metal sidewall, a metal bottom layer, a first corner portion between the first metal sidewall and the metal bottom layer, wherein the first corner portion comprises a first step and a first ramp, a second metal sidewall and a second corner portion between the second metal sidewall and the metal bottom layer, wherein the second corner portion comprises a second step and a second ramp.

Abstract: A method includes forming a dummy gate stack, forming a dielectric layer, with the dummy gate stack located in the dielectric layer, removing the dummy gate stack to form a opening in the dielectric layer, forming a metal layer extending into the opening, and etching back the metal layer. The remaining portions of the metal layer in the opening have edges lower than a top surface of the dielectric layer. A conductive layer is selectively deposited in the opening. The conductive layer is over the metal layer, and the metal layer and the conductive layer in combination form a replacement gate.

Abstract: A device comprises a metal gate structure over a substrate, wherein the metal gate structure comprises a first metal sidewall, a metal bottom layer, a first corner portion between the first metal sidewall and the metal bottom layer, wherein the first corner portion comprises a first step and a first ramp, a second metal sidewall and a second corner portion between the second metal sidewall and the metal bottom layer, wherein the second corner portion comprises a second step and a second ramp.

Abstract: A method comprises depositing a dielectric layer on sidewalls and a bottom of a trench of a gate structure, depositing a metal layer on the dielectric layer, depositing a protection layer on the metal layer, wherein an upper portion of a sidewall portion of the protection layer is thinner than a lower portion of the sidewall portion of the protection layer and etching back the metal wherein an upper portion of a first metal sidewall of the metal layer is thinner than a lower portion of the first metal sidewall and an upper portion of a second metal sidewall of the metal layer is thinner than a lower portion of the second metal sidewall.

Abstract: A method comprises depositing a dielectric layer on sidewalls and a bottom of a trench of a gate structure, depositing a metal layer on the dielectric layer, depositing a protection layer on the metal layer, wherein an upper portion of a sidewall portion of the protection layer is thinner than a lower portion of the sidewall portion of the protection layer and etching back the metal wherein an upper portion of a first metal sidewall of the metal layer is thinner than a lower portion of the first metal sidewall and an upper portion of a second metal sidewall of the metal layer is thinner than a lower portion of the second metal sidewall.

Abstract: A device comprises a metal gate structure over a substrate, wherein the metal gate structure comprises a first metal sidewall, a metal bottom layer, a first corner portion between the first metal sidewall and the metal bottom layer, wherein the first corner portion comprises a first step and a first ramp, a second metal sidewall and a second corner portion between the second metal sidewall and the metal bottom layer, wherein the second corner portion comprises a second step and a second ramp.

Abstract: A device comprises a metal gate structure in a trench and over a substrate, wherein the gate structure comprises a first metal sidewall in the trench, wherein the first metal sidewall becomes progressively thinner towards an upper portion of the first metal sidewall, a second metal sidewall in the trench, wherein the second metal sidewall becomes progressively thinner towards an upper portion of the second metal sidewall and a metal bottom layer on a bottom of the trench and between the first metal sidewall and the second metal sidewall.

Abstract: A method comprises depositing a metal layer partially filling a trench of a gate structure, forming a protection layer on the metal layer, wherein a sidewall portion of the protection layer is thinner than a bottom portion of the protection layer, removing a portion of the metal layer and removing the bottom portion of the protection layer.

Abstract: An aspect of this description relates to a method that includes partially filling an opening in a dielectric material with a high-dielectric-constant material. The method also includes partially filling the opening with a first metal material over the high-dielectric-constant material. The method further includes filling the opening with a capping layer over the first metal material. The method additionally includes partially removing the first metal material and the capping layer in the opening using a wet etching process in a solution including one or more of H2O2, NH4OH, HCl, H2SO4 or diluted HF. The method also includes fully removing the remaining capping layer in the opening using a wet etching process in a solution includes one or more of NH4OH or diluted HF. The method further includes depositing a second metal material in the opening over the remaining first metal material.