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 H.sub.2 SO.sub.4 rinsing 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 SiO.sub.2 dielectric layers.

대표청구항 ▼

[ The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.]1. A method for forming a Co--W--P--Au film on a substrate comprising the steps of:immersing a substrate having copper conductive regions in a solution comprising palladium ions for

[ The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.]1. A method for forming a Co--W--P--Au film on a substrate comprising the steps of:immersing a substrate having copper conductive regions in a solution comprising palladium ions for a length of time sufficient for palladium ions to deposit on surfaces of said copper conductive regions,immersing said substrate in a solution containing at least 15 gr/l of an agent selected from the group consisting of sodium citrate, ethylenediamine tetra acetic acid (EDTA) to remove excess palladium ions from said surfaces of copper conductive regions,rinsing said substrate with a fluid,electroless plating a Co--W--P film on said surfaces of copper conductive regions in a first plating solution comprising Co ions, tungstate ions, citrate ions and a reducing agent,rinsing said substrate with a fluid, andimmersing said substrate in a second plating solution without first conducting a replacement Au plating step for depositing a Au layer on top of said Co--W--P film.