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;
- generating a meta stable plasma using a first gas and a second gas, wherein the first gas is input into a first input of a shower head, and the second gas is input into a second input of the shower head to mix with radicals generated from the first gas;
- and
- using the meta stable plasma to treat the first high-k dielectric layer.
A method comprising:
- forming a metal layer comprising a first portion over a high-k dielectric layer;
- etching the first portion of the metal layer to reveal the high-k dielectric layer;
- treating the high-k dielectric layer using a meta stable plasma;
- and
- depositing a work function layer on the high-k dielectric layer.
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;
- depositing a first metal-containing layer over the second high-k dielectric layer;
- performing a treatment process on the first high-k dielectric layer using a meta stable plasma, wherein in the treatment process, the second high-k dielectric layer is separated from the meta stable plasma by the first metal-containing layer;
- and
- forming a second metal-containing layer and a third metal-containing layer over the first high-k dielectric layer and the first metal-containing layer, respectively.
Dependencies are inferred from the claim text.