Ni-pt alloy and target comprising the alloy

Abstract

The present invention provides a Ni—Pt alloy superior in workability containing Pt in a content of 0.1 to 20 wt % and having a Vickers hardness of 40 to 90, and a target comprising the Ni—Pt alloy. The present invention also provides a manufacturing method of Ni—Pt alloy superior in workability comprising a step of subjecting a raw material Ni having a purity of 3N level to electrochemical dissolution, a step of neutralizing the electrolytically leached solution with ammonia, a step of removing impurities through filtration with activated carbon, a step of blowing carbon dioxide into the resultant solution to form nickel carbonate and exposing the resultant product to a reducing atmosphere to prepare high purity Ni powder, a step of leaching a raw material Pt having a purity of 3N level with acid, a step of subjecting the leached solution to electrolysis to prepare high purity electrodeposited Pt, and a step of dissolving the resultant high purity Ni powder and high purity electrodeposited Pt. The foregoing method enables the rolling of the Ni—Pt alloy ingot upon reducing the hardness thereof, which results in the stable and efficient manufacture of a rolled target.

Description

TECHNICAL FIELD [0001] The present invention relates to a Ni—Pt alloy superior in workability, a sputtering target manufacturing by rolling a Ni—Pt alloy ingot, and a manufacturing method of such Ni—Pt alloy and Ni—Pt alloy target. BACKGROUND ART [0002] Ni—Pt is used as a sputtering target for semiconductor devices, and this Ni—Pt target was conventionally manufactured with the powder metallurgy process. In other words, the target was manufactured by sintering Ni powder and Pt powder, or by sintering Ni—Pt alloy powder. [0003] Since it is impossible for a sintered product to become a 100% high density product, it is undeniable that such sintered product is inferior in terms of density in comparison to a target manufactured via melting, casting and rolling. [0004] Therefore, gas components easily get mixed into the target, and not only does this reduce purity, it causes abnormal electrical discharge during sputtering, induces the generation of particles, and deteriorates the depositi...

AI Technical Summary

Benefits of technology

[0016] As a result, the present invention is able to easily perform cool rolling to a dissolved Ni—Pt alloy ingot without requiring any equipment, such as preparing a mold with large heat capacity or a water-cooled mold, for accelerating the cooling speed in order to inhibit the coarsening of crystals, and yields a superior effect in that it is possible to improve the quality of the Ni—Pt alloy deposition by reducing impurities contained in the Ni—Pt alloy target and realizing high purification.

[0017] Further, in addition to being able to prevent the generation of fractures and cracks in the target, a significant effect is yielded in that the generation of particles which often occurred in conventional sintered targets and resulted from the abnormal electrical discharge of sputtering can be inhibited.

Problems solved by technology

Since it is impossible for a sintered product to become a 100% high density product, it is undeniable that such sintered product is inferior in terms of density in comparison to a target manufactured via melting, casting and rolling.

Therefore, gas components easily get mixed into the target, and not only does this reduce purity, it causes abnormal electrical discharge during sputtering, induces the generation of particles, and deteriorates the deposition characteristics.

Meanwhile, a Ni—Pt product formed via melting and casting has a problem in that it is extremely hard and brittle.

As a result, when a Ni—Pt ingot is rolled, there is a problem in that grain boundary fractures occur, and it is not possible to manufacture a flat and even planar target.

Nevertheless, with Patent Document 1, there is a drawback in that large equipment is necessary for preparing a mold with large heat capacity or a water-cooled mold, and there is a problem in that it is difficult to inhibit the coarsening of crystals unless the cooling speed is considerably fast.

Further, the crystals that come in contact with the mold are fine, and become coarse as they draw away from such mold.

Thus, there is a problem in that it is difficult to obtain a uniform crystal structure, and it is therefore not possible to manufacture a target having a uniform structure or that is stable.