Sb-Te-Based Alloy Sintered Compact Sputtering Target

Abstract

Provided is an Sb—Te-based alloy sintered compact sputtering target having Sb and Te as its main component and which contains 0.1 to 30 at % of carbon or boron and comprises a uniform mixed structure of Sb—Te-based alloy particles and fine carbon (C) or boron (B) particles, wherein the average grain size of the Sb—Te-based alloy particles is 3 μm or less and the standard deviation thereof is less than 1.00, the average grain size of C or B is 0.5 μm or less and the standard deviation thereof is less than 0.20, and, when the average grain size of the Sb—Te-based alloy particles is X and the average grain size of carbon or boron is Y, Y/X is within the range of 0.1 to 0.5. The present invention aims to improve the structure of the Sb—Te-based alloy sputtering target, inhibit the generation of cracks in the sintered target, and prevent the generation of arcing in the sputtering process.

Description

TECHNICAL FIELD[0001]The present invention relates to an Sb—Te-based alloy sintered compact sputtering target containing carbon or boron and capable of effectively inhibiting the generation of particles.BACKGROUND ART[0002]In recent years, a thin film formed from an Sb—Te-based material is being used as a material for use in phase change recording; that is, as a medium for recording information by using phase transformation. As a method of forming this thin film formed from the Sb—Te-based alloy material, it is standard to use a means generally referred to as a physical vapor deposition method such as the vacuum deposition method or the sputtering method. In particular, the thin film is often formed using the magnetron sputtering method from the perspective of operability and film stability.[0003]Formation of films by way of the sputtering method is performed by physically colliding positive ions such as Ar ions to a target disposed on a cathode, using that collision energy to disch...

AI Technical Summary

Benefits of technology

[0039]Since the Sb—Te-based alloy sintered compact of the present invention is able to inhibit abnormal structures such as lumps (coarse grains), which are clumps of the added carbon or boron which is nonmetal, it yields a superior effect of preventing abnormal discharge with such carbon or boron as the source, inhibit the generation of particles caused by arcing, and additionally improving the uniformity of the sputtered film.

[0040]Machining such as cutting work is performed at the stage of finishing the target, if there is coarsened carbon or boron, there is a possibility that cracks and the like will occur with such carbon or boron as the source, and the generation of particles with cracks as the source could also be considered, and the present invention is able to achieve a considerable effect of preventing the foregoing problems from occurring.

Problems solved by technology

When forming a film formed from an Sb—Te-based alloy material for use in a phase change recording film, particularly problematic are the generation of abnormal structures such as nodules (abnormal projections) and craters (abnormal recesses) on the target surface, generation of micro arcing (abnormal discharge) based on the foregoing abnormal structures, and the inclusion of such abnormal structures in the form of clusters (cluster of atoms) referred to as particles in the thin film.

Other problems include the generation of cracks or fractures in the target in the sputtering process, unevenness of the formed thin film, and the absorption of large amounts of gas components such as oxygen in the production process of sintered powder for use in a target which affects the film quality of the sputtered film.

These problems encountered in targets and in the sputtering process will become a significant cause of deteriorating the quality and yield of the thin film as the recording medium.

It is known that the foregoing problems are largely affected by the grain size of the sintering powder or the target structure or shape.

However, conventionally, it was not possible to avoid the generation of particles, abnormal discharge (arcing), and nodules and craters on the target in the sputtering process, generation of cracks or fractures in the target during the sputtering process, and the inclusion of large amounts of gas components such as oxygen contained in the target since the target obtained from the sintering is unable to retain sufficient characteristics upon producing an Sb—Te-based alloy sputtering target for forming a phase change recording layer.

Nevertheless, the foregoing Patent Documents use the atomized powder as is, and it is not possible to obtain a sufficient strength of the target, and it cannot be said that the refinement and homogenization of the target structure have been achieved.

In addition, there is a problem in that it is insufficient as an Sb—Te-based sputtering target for forming a phase change recording layer.

However, if carbon is mixed into a conventional Sb—Te-based alloy sputtering target, it will rather become an addition of foreign matter since carbon powder is non-metal; this will easily generate abnormal discharge in the sputtering process, the generation of particles will increase, and, in certain cases, cracks will occur in the target.

There is a problem in that this is not necessarily a favorable additive.

Nevertheless, with this technology, carbon or boron powder was adhered to the surface of the Sb—Te-based alloy powder or its cluster by using airflow or the like, and the diffusion of carbon powder or boron powder inside the cluster was insufficient.

In addition, there was a problem in that the carbon powder or boron powder would become a cluster and deteriorate the uniformity, and there was still room for improvement in this respect.

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