초록 ▼

A method for forming a quaternary alloy film of Co--W--P--Au for use as a diffusion barrier layer on a copper interconnect in a semiconductor structure and devices formed incorporating such film are disclosed. In the method, a substrate that has copper conductive regions on top is first pre-treated

A method for forming a quaternary alloy film of Co--W--P--Au for use as a diffusion barrier layer on a copper interconnect in a semiconductor structure and devices formed incorporating such film are disclosed. In the method, a substrate that has copper conductive regions on top is first pre-treated by two separate pre-treatment steps. In the first step, the substrate is immersed in a H2SO4rinsing solution and next in a solution containing palladium ions for a length of time sufficient for the ions to deposit on the surface of the copper conductive regions. The substrate is then immersed in a solution that contains at least 15 gr/l sodium citrate or EDTA for removing excess palladium ions from the surface of the copper conductive regions. After the pre-treated substrate is rinsed in a first rinsing step by distilled water, the substrate is electroless plated a Co--W--P film on the surfaces of the copper conductive regions in a first plating solution that contains cobalt ions, tungstate ions, citrate ions and a reducing agent. After the substrate coated with the Co--W--P film is rinsed in a second rinsing step by distilled water, the substrate is immersed in a second electroless plating solution for depositing a Au layer on top of the Co--W--P film. The present invention novel quaternary alloy film can be used as an effective diffusion barrier layer between a copper interconnect and silicon substrate or SiO2dielectric layers.

대표청구항 ▼

1. An alloy film comprising: a Co--W--P film layer, and a Au layer on top of said Co--W--P film layer with Au atoms diffused into said Co--W--P film layer forming a Co--W--P--Au alloy film, said Au layer having a thickness between about 200 .ANG. and about 2000 .ANG.. 2. An alloy film accordin

1. An alloy film comprising: a Co--W--P film layer, and a Au layer on top of said Co--W--P film layer with Au atoms diffused into said Co--W--P film layer forming a Co--W--P--Au alloy film, said Au layer having a thickness between about 200 .ANG. and about 2000 .ANG.. 2. An alloy film according to claim 1, wherein said Co--W--P film layer consists of between about 85% and about 95% Co, between about 1% and about 5% W, and between about 5% and about 9% P. 3. A Co--W--P--Au film comprising between about 90% and about 95% Co, between about 1% and about 3% W, between about 3% and about 5% P and between about 1% and about 2% Au. 4. An electronic structure comprising: an insulating material layer having a top surface, at least one copper bond pad formed on said top surface of said insulating material layer, a layer of Co--W--P--Au alloy overlying said at least one copper bond pad, and at least one solder ball on top of said at least one copper bond pad with said Co--W--P--Au film layer thereinbetween. 5. An electronic structure comprising: an insulating material layer having a top surface, at least one copper bond pad formed in said top surface of said insulating material layer, a layer of Co--W--P--Au alloy overlying said at least one copper bond pad, a ball-limiting metallurgy (BLM) layer on top of said Co--W--P--Au layer, and at least one solder ball planted on top of said BLM layer, said Co--W--P--Au layer and said at least one copper bond pad.