Barrier metal composite layer featuring a thin plasma vapor deposited titanium nitride capping layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsKuo-Hsien Cheng, Ting-Chun Wang
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Abstract
A process for fabricating a tungsten plug, in a deep, small diameter opening, featuring a novel adhesive-barrier composite layer, located along the sides of the deep, small diameter opening, has been developed. The process features the use of a first titanium nitride barrier layer, deposited on an underlying titanium adhesive layer, via chemical vapor deposition procedures, used to enhance the conformality properties of the first titanium nitride barrier layer. A second titanium nitride barrier layer is then deposited, via plasma vapor deposition procedures, protecting the underlying CVD titanium nitride layer from the environment, while providing an improved surface for subsequent nucleation of a CVD tungsten layer.
Claims20
A method of forming a metal plug, in an opening in an insulator layer, with a composite adhesive-barrier layer, located between said metal plug, and the surfaces of said opening in said insulator layer, comprising the steps of:
- providing a conductive region;
- forming an opening in an insulator layer, that overlays said conductive region, with said opening exposing a portion of the top surface of said conductive region;
- depositing an adhesive layer on the walls of said opening, in said insulator layer, and on the portion of said conductive region, exposed at the bottom of said opening;
- forming a first barrier layer on said adhesive layer;
- performing a plasma anneal procedure:
- depositing a second barrier layer on plasma annealed, said first barrier layer;
- and
- forming said metal plug in said opening, in said insulator layer, with said metal plug overlying, and interfacing, said second barrier layer.
A method of forming a tungsten plug, in a deep, narrow diameter opening in an insulator layer, featuring the use of a composite adhesive-barrier layer, located between said tungsten plug, and the surfaces of said opening, and with said composite adhesive-barrier layer comprised of an underlying titanium layer, a first titanium nitride layer, obtained via CVD procedures, and an overlying, second titanium nitride layer, obtained via PVD procedures, comprising the steps of:
- providing a conductive region;
- depositing an insulator layer;
- forming a deep, narrow diameter opening, in said insulator layer, exposing a portion of the top surface of said conductive region;
- depositing said titanium layer on the walls of said deep, narrow diameter opening, on the portion of said conductive region, exposed at the bottom of said deep, narrow diameter opening, and on the top surface of said insulator layer;
- depositing said first titanium nitride layer, via CVD procedures;
- performing a plasma annealing procedure on said first titanium nitride layer;
- depositing said second titanium nitride layer, via PVD procedures;
- depositing a tungsten layer, completely filling said deep, narrow diameter opening;
- and
- removing regions of said tungsten layer, regions of said second titanium nitride layer, regions of said first titanium nitride layer, and regions of said titanium layer, from the top surface of said insulator layer, forming said tungsten plug structure, surrounded by said composite adhesive-barrier layer, in said deep, narrow diameter opening.
Dependencies are inferred from the claim text.