Full density Co-W magnetic sputter targets

Abstract

A sputter target is provided with a first elemental phase of a first material, the first material being either cobalt or tungsten, a first intermetallic phase including the first material and a second material, the second material being either tungsten or cobalt and different from the first material, the first material in a greater atomic percentage than the second material, and a second intermetallic phase including the second material and the first material, the second material in a greater atomic percentage than the first material. The sputter target includes 20-80 at. % cobalt, and has a density greater than 99% of a theoretical maximum density thereof. The sputter target is fabricated by selecting a cobalt powder and a tungsten powder having the same particle size distribution, blending the cobalt powder and the tungsten powder to form a blended powder, canning the blended powder, hot pressing the blended powder to form a solid, and machining the solid to form a sputter target.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.FIELD OF THE INVENTION[0003]The present invention generally relates to sputter targets and, in particular, relates to full density cobalt-tungsten sputter targets and methods for manufacturing the same.BACKGROUND OF THE INVENTION[0004]The manufacture of full density cobalt-tungsten sputtering targets presents a number of challenges. Specifically, because of the difference in density between cobalt (Co) and tungsten (W), the elemental phases in a sputter target containing both tend to segregate during manufacture. Moreover, the formation of excessive intermetallic phases during manufacture can render the resultant alloy extremely hard, brittle, and prone to cracking during processing.SUMMARY OF THE INVENTION[0005]The present invention solves the foregoing problems by providing fully dense cobalt-tungsten sputter targets and methods of manufact...

AI Technical Summary

Benefits of technology

[0005]The present invention solves the foregoing problems by providing fully dense cobalt-tungsten sputter targets and methods of manufacturing the same. The targets may contain between 20-80 at. % cobalt and 80-20 at. % tungsten. The targets have a substantially uniform multi-phase microstructure, and are substantially chemically homogenous both across their surface and through their thickness (i.e., along the sputter direction). The optimized volume fractions of the intermetallic phases and the elemental phase(s) allow the targets to maintain mechanical strength (e.g., resistance to cracking during hot isostatic pressing, machining, or subsequent sputtering) and machinability while achieving a density greater than about 99% of a theoretical maximum density. The micro-cracks and micro-porosities that plague other cobalt-tungsten targets have been minimized.

Problems solved by technology

The manufacture of full density cobalt-tungsten sputtering targets presents a number of challenges.

Moreover, the formation of excessive intermetallic phases during manufacture can render the resultant alloy extremely hard, brittle, and prone to cracking during processing.

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