Method for enhancing the adhesion of a barrier layer to a dielectric

A method of depositing a tantalum-based layer with improved adhesion to an underlying dielectric material covered semiconductor substrate, said method comprising:

• forming a sacrificial layer of silicon having a thickness onto a dielectric layer on a semiconductor substrate;
• and
• depositing a layer of a tantalum-based material by thermal CVD onto the surface of the silicon layer by a chemical reaction of a gas mixture of a tantalum halide vapor-phase reactant and a reducing gas, during which said sacrificial layer of silicon is substantially removed, and wherein by-product halogen atoms are created by the chemical reaction;
• and
• during said depositing, preventing, by means of said sacrificial layer of silicon, a concentration of the by-product halogen atoms sufficient to affect the adhesion of the tantalum based-material and the dielectric from being incorporated near the interface between the dielectric layer and the layer of tantalum-based material.

A method of depositing a tantalum-based layer with unproved adhesion to an underlying dielectric material covered semiconductor substrate, said method comprising:

• forming a layer of silicon having a thickness onto a dielectric layer on a semiconductor substrate;
• and
• depositing a layer of a tantalum-based material by plasma-enhanced CVD onto the surface of the silicon layer by a chemical reaction of a gas mixture of a tantalum halide vapor-phase reactant, a reducing gas, and an inert gas, wherein by-product halogen atoms are created by the chemical reaction;
• and
• during said depositing. preventing. by means of said layer of silicon, a concentration of the by-product halogen atoms sufficient to affect the adhesion of the tantalum based-material and the dielectric from being incorporated near the interface between the dielectric layer and the layer of tantalum-based material.

A method of forming copper-based interconnects on a tantalum-based diffusion barrier layer with improved adhesion to an underlying dielectric material covered substrate, said method comprising:

• forming a layer of silicon having a thickness onto a dielectric layer on a substrate;
• depositing a diffusion barrier layer of a tantalum-based material selected from the group consisting of Ta and TaN2 by CVD onto the surface of the silicon layer by a chemical reaction of a gas mixture of a tantalum halide vapor-phase reactant and a reducing gas, wherein by-product halogen atoms are created by the chemical reaction;
• and
• during said depositing, preventing, by means of said layer of silicon, a concentration of the by-product halogen atoms sufficient to affect the adhesion of the tantalum-based material and the dielectric from being incorporated near the interface between the dielectric layer and the diffusion barrier layer of tantalum-based material;
• and
• depositing a copper-based layer onto the diffusion barrier layer to form said copper-based interconnects.

A method of forming copper-based interconnects on a tantalum-based diffusion barrier layer with improved adhesion to an underlying dielectric material covered semiconductor substrate, said method comprising:

• forming a layer of silicon having a thickness onto a dielectric layer on a semiconductor substrate;
• depositing a diffusion barrier layer of a tantalum-based material selected from the group consisting of Ta and TaNK by plasma-enhanced CVD onto the surface of the silicon layer by a chemical reaction of a gas mixture of a tantalum halide vapor-phase reactant, a reducing gas, and an inert gas, wherein by-product halogen atoms arc created by the chemical reaction;
• and
• during said depositing, preventing, by means of said layer of silicon, a concentration of the by-product halogen atoms sufficient to affect the adhesion of the tantalum-based material and the dielectric from being incorporated near the interface between the dielectric layer and the diffusion barrier layer of tantalum-based material;
• and
• depositing a copper-based layer onto the diffusion barrier layer to form said copper-based interconnects.