| CPC H01L 21/28185 (2013.01) [H01L 21/02321 (2013.01); H01L 21/28556 (2013.01); H01L 21/32134 (2013.01); H10D 64/01 (2025.01); H10D 64/667 (2025.01); H10D 64/685 (2025.01); H01L 21/28088 (2013.01); H01L 21/28097 (2013.01); H01L 21/28518 (2013.01); H01L 21/28568 (2013.01); H10D 30/024 (2025.01); H10D 30/62 (2025.01)] | 20 Claims |

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1. A structure comprising:
a semiconductor fin over a substrate;
a first source/drain region and a second source/drain region over the semiconductor fin;
a gate structure between the first source/drain region and the second source/drain region, the gate structure comprising:
a gate dielectric layer along sidewalls and over a top surface of the semiconductor fin, the gate dielectric layer comprising fluorine;
a capping layer over the gate dielectric layer, the capping layer comprising titanium-silicon nitride, titanium-carbon nitride, titanium-aluminum nitride, tantalum-silicon nitride, tantalum-carbon nitride, or aluminum nitride;
a barrier layer over the capping layer, the barrier layer comprising tantalum-carbon nitride, tantalum-aluminum nitride, titanium-carbon nitride, titanium-aluminum nitride, or aluminum nitride;
a first work-function tuning layer over the barrier layer, wherein the first work-function tuning layer comprises a majority of titanium-silicon nitride, titanium-carbon nitride, titanium-aluminum nitride, tantalum nitride, tantalum-silicon nitride (TaSixNy), tantalum-carbon nitride, or cobalt;
a second work-function tuning layer over the first work-function tuning layer, the second work-function tuning layer having a non-zero concentration of fluorine that is greater than a non-zero concentration of fluorine in the barrier layer, that is greater than a non-zero concentration of fluorine in the capping layer and that is greater than the non-zero concentration of fluorine in the first work-function tuning layer, wherein the second work-function tuning layer comprises titanium aluminum carbide (TiAlC), a titanium aluminum alloy, or tantalum-aluminum carbide;
a barrier/adhesion layer over the second work-function tuning layer, wherein the barrier layer has a non-zero concentration of tungsten that is higher than a non-zero concentration of tungsten within the first work-function tuning layer and is higher than a non-zero concentration of tungsten within the capping layer and is higher than a non-zero concentration of tungsten within the gate dielectric layer, the barrier-adhesion layer comprising titanium-silicon nitride, titanium-carbon nitride, titanium-aluminum nitride, tantalum-silicon nitride, or tantalum-carbon nitride; and
a metal gate electrode over the barrier layer, a concentration of fluorine in the gate dielectric layer being greater than the non-zero concentration of fluorine in the first work-function tuning layer and also being greater than the non-zero concentration of fluorine in the second work-function tuning layer.
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