Tuning threshold voltage through meta stable plasma treatment
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsShao-Jyun Wu, Sheng-Liang Pan, Huan-Just Lin
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Abstract
A method includes forming a first high-k dielectric layer over a first semiconductor region, forming a second high-k dielectric layer over a second semiconductor region, forming a first metal layer comprising a first portion over the first high-k dielectric layer and a second portion over the second high-k dielectric layer, forming an etching mask over the second portion of the first metal layer, and etching the first portion of the first metal layer. The etching mask protects the second portion of the first metal layer. The etching mask is ashed using meta stable plasma. A second metal layer is then formed over the first high-k dielectric layer.
Claims20
A method comprising:
- forming a first high-k dielectric layer in a first device region of a wafer;
- forming a second high-k dielectric layer in a second device region of the wafer;
- performing a first meta stable plasma treatment on the first high-k dielectric layer using nitrogen (N2) with a first flow rate;
- performing a second meta stable plasma treatment on the second high-k dielectric layer using nitrogen (N2) with a second flow rate different from the first flow rate;
- forming a first gate electrode over the first high-k dielectric layer;
- and
- forming a second gate electrode over the second high-k dielectric layer, wherein the first gate electrode and the second gate electrode are formed in a common formation process.
A method comprising:
- adjusting a first threshold voltage of a first transistor, wherein the adjusting the first threshold voltage comprises performing a first treatment process on a first high-k dielectric layer using a first meta stable plasma, with nitrogen (N2) and hydrogen (H2) being used as process gases, and with the nitrogen having a first process flow;
- adjusting a second threshold voltage of a second transistor to be different from the first threshold voltage, wherein the adjusting the second threshold voltage comprises performing a second treatment process on a second high-k dielectric layer using a second meta stable plasma, with nitrogen (N2) and hydrogen (H2) being used as process gases, and with the nitrogen having a second process flow different from the first process flow;
- and
- depositing a first work function layer and a second work function layer over the first high-k dielectric layer and the second high-k dielectric layer, respectively.
A method comprising:
- forming a first high-k dielectric layer and a second high-k dielectric layer on a wafer, wherein the first high-k dielectric layer and the second high-k dielectric layer are formed of a same high-k dielectric material;
- performing a first treatment process on the first high-k dielectric layer using a meta stable plasma;
- performing a second treatment process on the second high-k dielectric layer using a second meta stable plasma, and wherein the first treatment process and the second treatment process are performed using different process conditions;
- and
- forming a first metal-containing layer and a second metal-containing layer over the first high-k dielectric layer and the second high-k dielectric layer, respectively.
Dependencies are inferred from the claim text.