JPS61124565A - Manufacture of tellurium or tellurium alloy target material - Google Patents

Abstract

PURPOSE:To manufacture efficiently a uniform and large-sized target material having a high density by adjusting a particle size of a powder of Te or its alloy, bringing it to a vacuum packing to a vessel made of an elastic substance, and executing a cold hydrostatic pressure press forming. CONSTITUTION:An alloy containing at least >=10wt% Te is prepared as a target which is used in case of forming a thin film of a recording medium of an optical disk by extremely fragile Te or its alloy by a sputtering method. This alloy is crushed to a fine powder state of 60-635 meshes, packed in an elastic substance vessel of rubber, urethane, etc., made to form a vacuum state and sealed. It is pressed by a cold hydrostatic pressure press and a high density sintered body is formed by sintering the green compact, and it is used as a target. A large-sized target having a high density and a uniform material quality can be manufactured with a high yield by using Te or a Te alloy, whose material quality is extremely fragile.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of application for forming molds" This invention relates to the use of tellurium or tellurium alloy target materials used when forming tellurium or tellurium alloy thin film layers, which are recording media for optical discs, by sputtering. This is related to the method of sending a.

"Prior Art" As is well known, tellurium or a tellurium alloy has been put to practical use as a suitable material for the recording medium thin film layer of an optical disk, and the thin film layer is generally manufactured by a sputtering method. The target material used in this sputtering method consists of a circular or square plate and a banking plate (cooling plate) attached to it. Conventionally, the melt VD method or the powder sintering method has been adopted as a method for manufacturing a tellurium alloy target material for tellurium 17 for sputtering.

``Problem to be solved by the invention'' Among the conventional manufacturing methods mentioned above, in one method, the melting casting method, as is well known, tellurium itself is very brittle and is prone to breakage, including the alloy. Rushi is very bad. It was almost impossible to manufacture circular products with a diameter exceeding 100 mm (70 x 100 mm for square products).

t+, the other powder sintering method is based on a method in which a powdery sintered body KL is formed by a hot press method and this sintered body is used as a target material. Generally, in the conventional Hontopress method, the raw material powder is pressurized from one direction and exposed to high temperatures, so the resulting sintered body is relatively small due to the shape of the hot press, and It is difficult to avoid contamination from the container or volatilization of adsorbed gas, resulting in non-uniformity of @ degree and deviation from the compound composition.

Therefore, it is impossible to simultaneously produce a large number of target materials with the same shape and performance from such a sintered body, and the sputtered film using the obtained target material has a uniform thickness. However, there are disadvantages such as variations in surface smoothness and electrical characteristics.

This invention was made in view of the above circumstances, and has high density,
The object of the present invention is to provide a method that can efficiently produce a tellurium or tellurium alloy target material having uniform and large dimensions at a low cost.

"Ninth Means for Solving the Problem" The method of the present invention involves pulverizing a lump of tellurium or tellurium alloy using a grinder such as a ball mill, and preferably sieving this powder to make the particle size within a predetermined range. This method involves filling a container made of a powdery elastic material, sealing it in a vacuum, placing it in a cold isostatic press and applying pressure, and machining the resulting high-density uniform molded object to use it as a target material. Further, the present invention will be explained in detail.

First, in the method of the present invention, the tellurium alloy used as a raw material is an alloy containing tellurium of 1 ozl<4 or more, and the tellurium or tellurium alloy used is a powder of 60 to 63J mesh, preferably 100 to 631 mesh. shall be. This is powder or 60 mesh or more - hh, 6
If coarse particles larger than a mesh are mixed in, the strength of the press-formed product obtained will not increase, and cracks may occur during processing, cracks during sputtering, and density unevenness will occur, resulting in variations in sputtering speed. This is because abnormal discharge may occur during sputtering. On the other hand, if the particles become too fine below 4Jr mesh, the density of the molded product will be low.]
This is because it is difficult to mold and brittle, and therefore cracks occur during processing or during sputtering.

Also, if it is a powder raw material with a mesh size of 100 to 63j,
Under certain conditions, the variation in density ratio within a loft, between lofts, and within a plane can be suppressed to J%, and it is also possible to obtain a uniform press-formed product with high strength.

Following the powder preparation as described above, in the method of the present invention, the powder raw material is placed in an elastic material such as rubber or flexible container VC.
Pj, seal it in vacuum, and put it in a cold isostatic press to obtain a press molded product from all directions at room temperature 1. Therefore,
This press-formed body is much more uniform and denser than the T-shaped body obtained by the conventional hot press method. In addition, since the container made of the elastic material can have a large capacity of about 60mm x 00mm, the press molded product obtained can be produced with a larger capacity than the conventional hot press method. Become.

Further, since the raw material powder has a very large surface area and a high gas adsorption property, it is desirable to carry out vacuum degassing iodide treatment as a pretreatment for cold isostatic pressing. This vacuum degassing treatment makes it possible to provide a target material with higher density and uniformity than in the case of cold isostatic pressing alone. In addition, if this is true as the degassing treatment condition, the temperature is io
The optimal temperature range is from a degree Celsius or higher to a temperature where the vapor pressure of the powder itself is /Torr or less, and the degree of vacuum is i'I'o.
rr or less, and a treatment time of 7 to 5 hours is sufficient. This vacuum degassing treatment may be applied to the target material before sputtering depending on the case.

Furthermore, in the method of the present invention, by sintering the press molded body obtained by cold isostatic pressing, it is possible to further improve the density of the obtained molded body by several to 1 Oacs.

In addition, the method of the present invention employs a cold isostatic pressing method to produce a press-formed body that is the material of the target material, and if necessary, the cold isostatic pressing method may be added to the vacuum desorption method. Gas treatment and heat treatment are appropriately combined.

"Action" According to the above-mentioned method of the present invention, it is possible to obtain an effect similar to that of a manure.

Since cold isostatic pressing is carried out at room temperature, there is no volatilization of adsorbed gas from the powder raw material during the pressing process, and since the press is performed in all directions using hydrostatic pressure, the resulting press molded product is comparable to that obtained by conventional methods. It is much more uniform and has much higher density and strength than a molded body, and therefore can be machined into a desired shape with high dimensional accuracy by ordinary machining. In other words, the press-formed product of the present invention can be processed by 7-plane milling to achieve smoothness, cylindrical grinding to create roundness, and a large diamond cutter or hand saw to cut into multiple pieces of a certain thickness. Most machining processes can be applied.

On the other hand, in the case of sintered bodies made using the conventional hot pressing method, adsorbed gases from the powder raw materials volatilize during pressing, and as a result, the sintered bodies obtained have uneven density and become brittle. Put it away.

(11) Cold isostatic pressing can be performed at room temperature, or powders with high vapor pressure can also be pressed. In the case of the second compound as well, the composition ratio of the powder as the starting material remains and is maintained in the molded product after cold isostatic pressing. On the other hand, in the conventional hot pressing method, if the powder itself has a high vapor pressure, it will volatilize due to the high temperature during pressing, and especially in the case of alloys, the composition will shift, making it unsuitable as a target material. I end up.

411) Since cold isostatic pressing is carried out at room temperature, there is little contamination from the press container, and even if there is contamination, it is limited to the surface layer of the press-formed product.

Therefore, the contaminated upper surface can be easily removed during post-processing such as machining, degreasing, and pickling in subsequent steps, and a target material with extremely high purity, which cannot be obtained using conventional methods, can be obtained.

(IV) As is clear from the descriptions of (1) to 4iD above, a large-capacity press-formed body can be machined into the same shape, uniform, high density, high strength, and with high dimensions.
It is possible to produce a large number of i1 degree target materials at once. Therefore, these target materials are easy to handle, and there is no need to set sputtering conditions for each target material, making it possible to efficiently provide uniform, high-quality optical recording medium thin film layers. . On the other hand,
In the case of the conventional hot pressing method, the obtained sintered body is relatively small in one shape as described above, and may have non-uniform density due to volatilization of intake gas during contamination from the press container, and a compound composition. Due to misalignment and poor processability, it is impossible to produce a large number of target materials with the same shape and performance at once, and the obtained target materials require careful handling. The sputtering conditions also need to be reset depending on the target material.

Next, examples of the method of the present invention will be shown.

"Example" As shown in Table 1, seven types (Example) to 7) of raw material powders with compositions and particle sizes were adjusted, and among them, Example No. and No. 7
was not subjected to true nitrogen degassing treatment, and Examples 2 to ≦ were each /
True nitrogen degassing treatment was performed at a temperature below Torr and at each temperature and time shown in the same table. After this, each raw material powder was placed in a rubber container with the capacity shown in Table 1 according to the conditions shown in the same table, and cold isostatically pressed for j minutes at each press pressure to obtain a molded body. .

Nine examples 俤, obtained as above! The compacts were machined as they were to the dimensions shown in Table IK, and the compacts of other examples were sintered at the temperature and time shown in the same table. Machined into seven. The number of target materials shown in Table 1 was obtained from each molded body before machining. The resulting target material has no cracks due to machining. Furthermore, no cracks were observed when sputtering each target material.

On the other hand, when a comparative example was prepared using the manufacturing method, conditions, composition, particle size, and machining dimensions shown in Table 1, cracks due to mechanical and sputtering occurred as shown in the same table.

"Effects of the Invention" As explained above, the method of the present invention produces a tellurium or tellurium alloy target for sputtering that is uniform, high density, relatively large capacity, high performance, and easy to handle. A large number of materials can be efficiently produced at once,
As a result, it is possible to provide a large quantity of uniformly high quality optical recording medium thin films.

Procedural amendment (voluntary)

Claims (6)

[Claims] (1) Powder of tellurium or an alloy containing tellurium is packed into a container made of an elastic material, the container is sealed in a vacuum, and the container is uniformly pressurized using a cold isostatic press to produce a high-density uniform molded body. A method for producing a tellurium or tellurium alloy target material, which comprises machining it into a sputtering target material. (2) After vacuum degassing the powder of tellurium or an alloy containing tellurium, the powder is packed in a container made of an elastic material,
A tellurium or tellurium alloy target material characterized by sealing the container in a vacuum, applying uniform pressure to the container using a cold isostatic press, and machining the obtained high-density uniform molded product to make a sputtering target material. Production method. (3) Powder of tellurium or an alloy containing tellurium is packed into a container made of an elastic material, the container is sealed, and the container is uniformly pressurized using a cold isostatic press, and the resulting high-density uniform compact is sintered. 1. A method for producing a tellurium or tellurium alloy target material, the method comprising: applying mechanical pressure to obtain a sputtering target material. (4) After vacuum degassing the powder of tellurium or an alloy containing tellurium, the powder is packed in a container made of an elastic material,
This is sealed in a vacuum, and the container is uniformly pressurized using a cold isostatic press, and the obtained high-density uniform molded body is sintered and then machined to be used as a sputtering target material. Or a method for manufacturing a tellurium alloy target material. (5) The method for producing a tellurium or tellurium alloy target material according to any one of claims 1 to 4, wherein the tellurium-containing alloy is an alloy containing 10% by weight or more of tellurium. (6) The tellurium or tellurium alloy according to any one of claims 1 to 4, wherein the tellurium or tellurium-containing alloy powder has a particle size of 60 to 635 mesh, preferably 100 to 635 mesh. Method for manufacturing target material.