Method for the formation of diffusion barrier

#1. Field of the Invention

#This invention relates to the making of electronic components such as semiconductor wafer VLSI and ULSI integrated circuit devices, and, more particularly, to a method for forming a robust barrier layer in the device interconnects with excellent step coverage, uniformity, low resistance and enhanced adhesion to CVD-copper and to the electronic components made by the method.

#2. Description of Related Art

#The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale the invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

#FIGS. 1A-1C show a sequence of steps for forming a metal rich surface on a dielectric according to a method of the invention.

#FIGS. 2A-2B show a sequence of steps for forming a metal rich surface on the surface of a dielectric according to another method of the invention.

#In describing the preferred embodiment of the present invention, reference will be made herein to FIGS. 1A-5 of the drawings in which like numerals refer to like features of the invention. Features of the invention are not necessarily shown to scale in the drawings.

#Referring to FIG. 1A, part of a multilayer electronic component is shown schematically and comprises a dielectric layer 10 having a diffusion barrier layer 11 thereon. As will be shown more fully hereinbelow, the dielectric layer 10 is used to form a multilayer electronic component and typically has openings therein in the form of vias and/or lines which are coated with a barrier layer 11. FIG. 1A shows schematically the dielectric layer 10 and the diffusion barrier layer 11 for convenience.

#The dielectric layer 10 may be made of any suitable dielectric material depending on the application for the electronic component and includes materials such as silicon dioxide, fluorinated silicon oxide, a polymer such as polyimide, a diamond-like carbon or a spin on glass. The barrier layer 11 may likewise be any suitable material that provides a diffusion barrier between the conductor formed in the dielectric and the dielectric. Preferred diffusion barrier materials are refractory materials such as tantalum, tungsten, tantalum nitride, tungsten nitride, silicon nitride, titanium, titanium nitride, hafnium, hafnium nitride and the like. As will be more fully discussed hereinbelow the diffusion barrier may be a silicon containing refractory material which is used in another aspect of the invention to provide a robust barrier layer.