Contact plug with impurity variation
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Chiang Wu, Hsueh Wen Tsau, Chia-Ching Lee, Cheng-Lung Hung, Ching-Hwanq Su
Life of this patent
Estimating the term…
Abstract
A method includes forming an opening in a dielectric layer, depositing a seed layer in the opening, wherein first portions of the seed layer have a first concentration of impurities, exposing the first portions of the seed layer to a plasma, wherein after exposure to the plasma the first portions have a second concentration of impurities that is less than the first concentration of impurities, and filling the opening with a conductive material to form a conductive feature. In an embodiment, the seed layer includes tungsten, and the conductive material includes tungsten. In an embodiment, the impurities include boron.
Claims20
A semiconductor device comprising:
- a dielectric layer;
- and
- a contact plug in the dielectric layer, the contact plug comprising:
- a conductive material;
- and
- a conductive layer along sidewalls of the conductive material, a first portion of the conductive layer proximal a first end of the conductive material comprising a first concentration of a first impurity, a second portion of the conductive layer proximal a second end of the conductive material comprising a second concentration of the first impurity, wherein the first end of the conductive material is opposite the second end of the conductive material, and wherein the second concentration of the first impurity is less than the first concentration of the first impurity, wherein the first impurity comprises oxygen.
A semiconductor device comprising:
- a conductive feature;
- a first dielectric layer over the conductive feature;
- and
- a contact plug extending through the first dielectric layer to the conductive feature, wherein the contact plug comprises a first conductive layer and a second conductive layer over the first conductive layer, wherein an upper surface of the first conductive layer is recessed from an upper surface of the second conductive layer, wherein the first conductive layer has a first concentration of impurities adjacent a lower sidewall of the first dielectric layer and a second concentration of impurities adjacent an upper sidewall of the first dielectric layer, wherein the first concentration of impurities is greater than the second concentration of impurities, wherein the impurities comprise boron impurities or oxygen impurities.
A semiconductor device comprising:
- a conductive feature;
- a first dielectric layer over the conductive feature, the first dielectric layer having an opening extending from an upper surface of the first dielectric layer to the conductive feature;
- a barrier layer extending along a sidewall of the opening in the first dielectric layer;
- a first conductive layer over the barrier layer, the first conductive layer having a first concentration of oxygen impurities at a first point on the sidewall of the opening in the first dielectric layer, the first conductive layer having a second concentration of oxygen impurities at a second point on the sidewall of the opening in the first dielectric layer, the first point being higher than the second point, the first concentration of oxygen impurities being less than the second concentration of oxygen impurities;
- and
- a second conductive layer over the first conductive layer.
Dependencies are inferred from the claim text.