JPS62148362A - Manufacture of target material for sputtering - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a target material used, for example, in forming a recording medium thin film of an optical disk by sputtering.

[Prior Art] Generally, for example, a recording medium thin film of an optical disk contains 50% by weight or more of one or two of Te and Te oxide (hereinafter referred to as TeO□), and the remainder is d203I.
5b203. Bi, Q3. Qa2Q3. GeO□
, In2O3゜PbO* MgO+ SiO, Ta
The recording medium thin film is formed by sputtering, and is made of a Te-based composite material consisting of one or more oxides from the group consisting of O, SnO□, and ZnO, and therefore the target material used for this is It is also well known that the target material is made of the above-mentioned Te-based composite material and that this target material is manufactured by a hot pressing method.

[Problem that the invention seeks to solve]

However, the above-mentioned hot press method is a method in which raw material powder consisting of a mixed powder of Te powder and/or TeO□ powder and oxide powder is sintered while being pressed from both the top and bottom or left and right directions. Not only is it difficult to manufacture large-sized sintered bodies due to restrictions on their shape, but the sintered bodies may be contaminated from the press container, oxidized by residual oxygen, and the density may decrease due to volatilization of adsorbed gas. Due to the non-uniformity (), it is impossible to produce a homogeneous target material with stable quality, and therefore, when a recording medium thin film is formed using the target material obtained as a result, However, there are problems such as variations in copyability, surface smoothness, and electrical characteristics.

[Means for solving problems]

Therefore, from the above-mentioned viewpoint, the present inventors conducted research to solve the problems of the conventional target material manufacturing method described above, and found that (at) Te powder and/or T
A mixed powder is used, in which eO□ powder and oxide powder are uniformly mixed and ground using a mixer such as a ball mill. This raw material powder is packed into a container made of an elastic material such as rubber or urethane, vacuum-sealed, and the vacuum-sealed container is subjected to a cold isostatic press. Because the pressure is applied uniformly from all directions, not only can a high-density and homogeneous green compact be formed, but there are almost no restrictions on its dimensions, such as diameter: 600Wφ x length: 1000m.
It is possible to mold a large-capacity green compact, and since the molding is performed at room temperature, even if raw material powder with high vapor pressure is used, it will volatilize due to the high temperature and the composition will be reduced. However, there should be no deviation in the composition.

(b) Since the resulting green compact is homogeneous and has high density and high strength as described above, it may be subjected to surface grinding to achieve smoothness or cylindrical molding to create a perfect circular shape. Since it can be applied to most machine processing such as grinding and cutting out multiple pieces of a certain thickness using a diamond cutter or band saw, it is possible to process 8i width of target material with high dimensional accuracy. In addition, there is little contamination from containers made of elastic materials, and even if there is contamination, it is limited to the surface of the green compact, so it is possible to prevent surfaces contaminated by post-processing such as mechanical roteing, degreasing, and pickling. part can be easily removed.

(c) the result is therefore homogeneous, has high density and high strength, is easy to handle and has high dimensional accuracy;
Moreover, it is possible to perform high-quality production with simple operations at low cost.Furthermore, if target materials with extremely low oxygen content and consistent composition are used, there is no need to reset sputtering conditions for each target material. It is possible to efficiently form a high-quality recording medium thin film without any variation in deafness.

(dl) Also, since the above raw material powder has a very large surface area and has gas adsorption properties, if vacuum degassing is performed before vacuum-sealing the container, the density of the molded green compact will increase. In this case, the optimal vacuum degassing treatment conditions are a predetermined temperature within the range of 100°C to a temperature at which the vapor pressure of the powder itself is 1 torr. The temperature may be 1 torr or less and the processing time may be 1 to 5 hours, and in some cases, this vacuum degassing treatment may be applied to the target material before sputtering.

(el Furthermore, when the above green compact is sintered under normal conditions in an inert gas atmosphere, the density of the sintered compact is several percent to
To be able to improve in a range of 10 or more.

The findings shown in (a) to (el) have been obtained above.

The present invention has been made based on the above findings, and includes a raw material powder composed of a mixed powder containing 50% by weight or more of Te@Song and/or TeO□ powder SONG, with the remainder being an oxide powder. Alternatively, the raw material powder that has been subjected to vacuum degassing treatment is packed into a container made of an elastic material, and this is vacuum-sealed,
This vacuum-sealed container is then subjected to all-round compression using a cold isostatic press.
A high-density homogeneous green compact is formed by applying IJD pressure, and if necessary, this green compact is sintered in a normal inert atmosphere to form a compact. Or Q from sintered body
This method is characterized in that the sputtering target material is formed by the mT'Jo process.

In carrying out the method of the present invention, it is preferable that the particle size of the raw material powder is in the range of 100 to 625 meshes, as described above, and this is because the particle size of the raw material powder is 60 meshes or more. If coarse particles with a mesh size of 1.6° or more are mixed into the raw material powder, cracks may occur during machining or sputtering, uneven density may occur, sputtering speed may vary, and abnormal discharge may occur during sputtering. occurs, while
The particle size is fine, 625 mesh or less, or 62
If many fine particles of 5 mesh or less are mixed in, the density of the compact will not only decrease, but also the formability will decrease, making it brittle, and cracks will occur during machining and sputtering. This is because it makes it easier to do so, and in this case,
When the particle size is set to 100 to 625 mesh, there is almost no variation in density under certain conditions, and it becomes possible to mold a green compact with even higher density and higher strength.

〔Example〕

Next, the method of the present invention will be specifically explained using examples.

As raw material powders, Te powder, TeO2 powder, and various oxide powders, all of which have a particle size of 60 mesh or less, were prepared, and these raw material powders were blended into the composition shown in Table 1, using a dry ball mill. 1 t
In a vacuum of orr or less, with or without vacuum degassing treatment under the conditions shown in Table 1,
A rubber container made of an elastic material having dimensions also shown in Table 1 was filled with the raw material powder of cypress shown in Table 1, vacuum-sealed, and then heated at the pressure shown in Table 1 for 5 minutes. A green compact is formed by cold isostatic pressing, and then sintered directly from the green compact or by sintering the green compact in an Ar atmosphere under the conditions shown in Table 1. Methods 1 to 14 of the present invention were carried out by molding target materials having the dimensions and numbers shown in Table 1 from the solid body using a machine υRoe.

For the purpose of comparison, conventional hot pressing methods 1 to 5 were carried out under the conditions shown in Table 2, and the resulting sintered bodies were machined to have the dimensions shown in Table 2. A number of target materials were prepared respectively.

Next, for the target materials obtained by the methods 1 to 14 of the present invention and the conventional hot press methods 1 to 5, the number of cracks generated after mechanical roteing was observed, and the number of cracks generated by sputtering was measured by incorporating it into a sputtering device. Observed. These results are shown in Tables 1 and 2, respectively.

〔Effect of the invention〕

From the results shown in Tables 1 and 2, it can be seen that methods 1 to 1 of the present invention
The target material manufactured by No. 14 has high density, high strength, and excellent homogeneity, so it is difficult to crack during machining or sputtering. It is clear that in the target materials manufactured by hot pressing methods 1 to 5, cracking during machining and sputtering is extremely significant.

As described above, according to the method of the present invention, it has high density and high strength, is easy to handle, has high dimensional accuracy,
Furthermore, target materials with extremely low oxygen content and no deviation in composition can be produced with simple operations and high yields. Moreover, with the resulting target materials, sputtering conditions can be set for each target material. Shina 2
Industrially useful effects such as the ability to efficiently form a uniform, high-quality thin film of a recording medium without the need for further processing are brought about.

Claims (6)

[Claims] (1) A raw material powder composed of a mixed powder containing 50% by weight or more of one or two of Te powder and Te oxide powder, with the remainder being oxide powder, is packed in an elastic material container. , vacuum-seal this, apply uniform pressure in all directions using a cold isostatic press to this vacuum-sealed container to form a high-density homogeneous green compact, and machine this green compact into a sputtering target material. A method for producing a sputtering target material characterized by: (2) The method for producing a sputtering target material according to claim 1, wherein the raw material powder is subjected to vacuum degassing treatment prior to being vacuum-sealed in the container. (3) The raw material powder has a particle size within the range of 60 to 635 mesh.
A method for producing a sputtering target material according to item 1) or item (2). (4) A raw material powder composed of a mixed powder containing 50% by weight or more of one or two of Te powder and Te oxide powder, with the remainder being oxide powder, is packed in an elastic material container. This is vacuum-sealed, and this vacuum-sealed container is subjected to uniform pressure in all directions using a cold isostatic press to produce a high-density homogeneous green compact, and then this green compact is sintered in an inert atmosphere. A method for producing a sputtering target material, which comprises forming a sintered body into a solid body, and machining the sintered body into a sputtering target material. (5) The method for producing a sputtering target material according to claim (4), characterized in that the raw material powder is vacuum degassed prior to being vacuum-sealed in the container. (6) The raw material powder has a particle size within the range of 160 to 635 mesh.
The method for producing a sputtering target material according to item 4) or item (5).