Method of forming sputtering target assembly and assemblies made therefrom

Abstract

A method of forming a sputtering target assembly is described that involves explosively bonding a target grade plate and a backing plate member to form a bonded preform having dimensions such that a large target or several target assemblies can be obtained. The method includes optionally partitioning the bonded preform into a plurality of sputtering target assemblies. An interlayer can optionally be disposed between the target grade plate and the backing plate member before bonding. A bond quality test sample can be produced by the method. The sputtering target assemblies, the bonded preform, and the bond quality test sample are further described.

Description

[0001] This application claims the benefit under 35 U.S.C. .sctn.119(e) of prior U.S. Provisional Patent Application No. 60 / 450,196 filed Feb. 25, 2003, which is incorporated in its entirety by reference herein.[0002] The present invention relates to a method of forming a sputtering target assembly. More specifically, the method includes the preferred use of explosion bonding to form a sputtering target assembly.[0003] Numerous bonding techniques are used to bond sputtering target assembly components (e.g., a sputter target or target blank and a backing plate) together, such as soldering, brazing, diffusion bonding, mechanical fastening, epoxy bonding, friction welding, explosion bonding, etc. Each of the bonding techniques has its own advantages and disadvantages. A common disadvantage of conventional bonding techniques is the individual bonding of a target and a backing plate, i.e., sputtering target assemblies are formed one at a time. Singularly forming sputtering target assembl...

AI Technical Summary

Benefits of technology

[0007] It is therefore a feature of the present invention to provide an improved method of bonding a target and a backing plate to form a sputtering target assembly.

[0011] An additional feature of the present invention is to provide a method to explosively bond a target grade plate and backing plate whereby the metallurgical properties of the target plate are not significantly altered by the bonding process.

[0012] Yet another feature of the present invention is to provide a method to explosively bond a target plate and a backing plate so as to minimize the defectively bonded area resulting from the explosive bonding process.

Problems solved by technology

A common disadvantage of conventional bonding techniques is the individual bonding of a target and a backing plate, i.e., sputtering target assemblies are formed one at a time.

First, it can be quite time-consuming and resource intensive, owing to the batch nature of production and inherent costs of the bonding process.

Another drawback concerns quality control.

However, variables in the bonding process affecting bond integrity can lead to uncertainty as to the relatedness of the bond quality of one sputtering target assembly to that of another.

Moreover, sacrificing a certain percentage of otherwise usable sputtering target assemblies for quality control purposes adds to the overall cost of sputtering target assembly production.

Another disadvantage of conventional bonding techniques is that they are feasible only for a sputtering target of limited size.

That is due, in part, to the fact that shear failure of conventional bonds increases with increasing temperatures reached during use (i.e., in the sputtering process).

The sputtering behavior of the edges of the individual target "tiles" may differ from that of the bulk of the target array, resulting in a deposited film having diminished thickness uniformity.

However, in the past, several technical and manufacturing related issues had prevented explosive bonding from being used for the fabrication of sputtering targets.

In addition, explosive bonding has been deemed a relatively costly bonding technique compared to conventional bonding processes.

At least some of the additional cost of explosion bonding is attributed to added material costs associated with what is commonly referred to as the "edge effect."

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