US 6,607,977 B1 · Method of depositing a diffusion barrier for copper interconnect applications

Abstract

The present invention pertains to methods for forming a metal diffusion barrier on an integrated circuit wherein the formation includes at least two operations. The first operation deposits barrier material via PVD or CVD to provide some minimal coverage. The second operation deposits an additional barrier material and simultaneously etches a portion of the barrier material deposited in the first operation. The result of the operations is a metal diffusion barrier formed in part by net etching in certain areas, in particular the bottom of vias, and a net deposition in other areas, in particular the side walls of vias. Controlled etching is used to selectively remove barrier material from the bottom of vias, either completely or partially, thus reducing the resistance of subsequently formed metal interconnects.

Claims73

Dependent claims

A method for depositing a diffusion barrier and a metal conductive layer for metal interconnects on a wafer substrate, the method comprising:

(a) depositing a first portion of the diffusion barrier over the surface of the wafer substrate;
(b) etching the first portion of the diffusion barrier at the bottom of a plurality of vias without fully etching through such that an amount of barrier material remains at the bottom of the plurality of vias, while depositing a second portion of the diffusion barrier elsewhere on the wafer substrate;
and
(c) depositing the metal conductive layer over the surface of the wafer substrate such that the metal conductive layer contacts the barrier material remaining at the bottom of the plurality of vias;
wherein at least part of (a) and all of (b) are performed in the same processing chamber.

2 more elements

Dependencies are inferred from the claim text.

Method of depositing a diffusion barrier for copper interconnect applications

Life of this patent

Method of depositing a diffusion barrier for copper interconnect applications

Life of this patent

Abstract

Claims73