Ohmic contact plug having an improved crack free TiN barrier metal in a contact hole and method of forming the same
AssigneeNEC Electronics Corporation
InventorsYoshiaki Yamada, Takashi Yokoyama
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Abstract
A sputtering method of depositing a titanium nitride film on a titanium film in contact with a silicon at a bottom of a contact hole is provided, wherein the sputtering method is carried out at a temperature of the silicon region of not less than 450° C., so that the titanium nitride film has a compressive stress of not higher than 5×109 dyne/cm2 whereby the titanium film has such a high stability as preventing any crack upon changing the compressive stress to a tensile stress by a heat treatment.
Claims8
A multilayer structure on a bottom of a contact hole, said multilayer structure comprising a titanium film on a silicon region and a titanium nitride film on said titanium film,
- wherein said titanium nitride film has a compressive stress of not higher than 3×109 dyne/cm2 so that said titanium film has such a high stability as preventing any crack upon changing said compressive stress to a tensile stress by a heat treatment.
A contact plug structure in a contact hole in an inter-layer insulator on a silicon substrate, said contact plug structure comprising:
- a titanium film on a bottom and a side wall of said contact hole;
- a titanium nitride film on said titanium film;
- a metal plug on said titanium nitride film so that said metal plug buries said contact hole;
- and
- a titanium silicide layer in a surface region of said silicon substrate and in contact with a bottom of said contact hole,
- wherein said titanium nitride film free of any crack and has a tensile stress of not higher than 2×109 dyne/cm2.
Dependencies are inferred from the claim text.