JPS62114136A - Production of sputtering target for optical recording - Google Patents

Abstract

PURPOSE:To stabilize sputtering conditions with a uniform compsn. having a high density and to improve productivity by mixing titanium, etc., with selenium, bringing the same into reaction by heating in a vacuum or inert gaseous atmosphere, adding tellurium to the mixture and pulverizing the mixture then molding the powder under pressurization. CONSTITUTION:The sputtering target for optical recording is obtd. by mixing >=1 kinds of metals such as titanium and silver with a selenium alloy, bringing the mixture into reaction by heating in the vacuum or inert gaseous atmosphere, adding a tellurium alloy to the mixture, pulverizing and mixing the same in the nonoxidative atmosphere and subjecting the mixture to molding under pressurization then to cutting and finishing. These materials are mixed at ratios of 60-100% tellurium, <=30% selenium and <=20% >=1 kinds of metals such as titanium, silver, arsenic and lead. The uniform compsn. approximately equal to the theoretical density is thus obtd. by pulverizing and mixing. The inter- particle binding power is increased by the improvement of sinterability, by which the sputtering conditions are stabilized. The productivity is improved by the continuous sputtering.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to write-once type (DRAW: direct r.
The present invention relates to a method for manufacturing a target that is a raw material for sputtering an optical recording disk (read after write).

[Prior Art] The first characteristic of optical disk memory is its large storage capacity. Compared to magnetic disks and VTRs, the recording density per unit area is at least 1
It is as high as 0 times or more. Recently, high-capacity magnetic recording memory is expected to emerge due to the development of perpendicular magnetization films, but with magnetic recording methods, wear and tear due to touch and run between the head and the disk cannot be avoided when reading records.
I am facing a lifespan problem.

On the other hand, in the case of light, although it is limited by the wavelength and the aperture of the lens, it has a high potential because it is possible to form a minute spot with a diameter of about 1 μm or less by using a laser.

The second feature is that recording and playback can be performed without contact. As a result, there is no wear and tear on the disk and hardware, resulting in a longer lifespan and higher reliability.

Among optical disk memories, read-only (ROM; rea)
d only memory) have become widely used as optical video discs and compact discs, and some of the write-once type still image disc files and document files that form the core of this invention have also been put into practical use.

Traditionally, optical disks have been manufactured using vapor deposition methods, sputtering methods using a composite target (a combination of several metals in a mosaic pattern, or one metal on top of another), or a sputtering method using a single metal. Multidimensional sputtering methods using a plurality of configured targets have been used.

This is due to the consideration of film composition and the fact that a single metal can provide a higher purity target than conventional alloy targets, but on the other hand, the complexity of the equipment configuration and the difficulty of continuously controlling the film composition Therefore, there were drawbacks such as difficulty in continuous production, low productivity, and high cost.

[Problems to be solved by the invention] The present invention enables sputtering that enables continuous control of the film composition, which was difficult with the conventional techniques as described above, and enables a large-scale, high-productivity film with a uniform composition. The present invention provides a method for manufacturing an alloy target that can be measured.

[Means for Solving the Problems] The present invention involves mixing one or more metals selected from the group consisting of titanium, silver, arsenic, lead, antimony, and indium with selenium or a selenium alloy, and then heating the mixture under vacuum or argon. ,
A heating reaction is carried out under an inert gas atmosphere such as nitrogen or helium to form selenide. Tellurium or a tellurium alloy is added to this, and the resulting fine powder mixture is pulverized and mixed in a non-oxidizing atmosphere, for example in an organic solvent. Hot press or
Or, a method for producing a sputtering target for optical recording, characterized by forming a green compact by cold isostatic pressing (CI P), followed by hot pressing to obtain a compact having a substantially uniform composition and approximately the same theoretical density. It provides:

In the present invention, the mixing ratio of each element is generally 60 at% or more but less than 100 at% for tellurium and 30 at% for selenium.
Other titanium, silver, arsenic, and lead are listed below.

20 at % or less of one or more metals selected from the group consisting of antimony and indium is employed.

Next, a method for manufacturing a target according to the present invention will be explained.

First, selenium or a selenium alloy is added to one or more metals selected from the group consisting of titanium, silver, arsenic, lead, antimony, and indium, and the mixture is heated under vacuum or in an inert gas atmosphere such as argon, nitrogen, helium, etc. The heating reaction is carried out at 1100°C.

This is then cooled to obtain selenide. Here, as a cooling method after the heating reaction, rapid cooling is preferable.

This is because it is thought that amorphous or fine crystals have a better effect on sputtering.

Add tellurium or tellurium alloy to the obtained selenide,
The resulting fine powder mixture (average particle size: 1 to 100 μm - preferably 2 to 20 μm) is thoroughly mixed in a kneader and subjected to cold isostatic pressure. After pressing (CIP) to 1 to 5 ton/cJ, preferably 3 to 5 ton/C- to obtain a green compact, it is made into a hot press ingot of a predetermined size. When hot pressing the powder, the powder is dried and mixed uniformly to form the raw material. The particle size of the raw material powder such as tellurium powder used here is generally 200 μm or less. This is heated for 10k using a hot press at 300-450℃, preferably 300-400℃ under an inert gas atmosphere.
g/c+ or more, preferably at a pressure of 75 to 200 kg/e- to obtain a molded body.

-6= This molded body is cut and finished using a cutting machine such as a wire electric discharge machine or a band saw to obtain a sputtering target for optical recording in a predetermined shape.

[Effects of the Invention] The target thus obtained has a substantially uniform composition and has approximately the same theoretical density. Furthermore, the sinterability is improved and the bonding force between particles is increased.

The optical recording target obtained according to the present invention is formed into a film by sputtering to form an optical disc.

In this case, there are the following advantages compared to an optical disk obtained by forming a film from a conventional composite target (mosaic type) or a target in which chips of other metals are mounted on a single metal.

(1) A film having the same composition as the target is obtained and the sputtering conditions are stabilized.

(2) Continuous sputtering becomes possible, improving productivity and reducing costs.

[Examples] The present invention will be explained below using examples. The present invention is not equally limited by these examples.

Example I Se 30.6wt%, Sb 47.18vt%.

In a quartz sealed tube at a rate of 22.22 vt%, 40
A heating reaction was carried out at 0 to 500°C for 5 hours, and the obtained selenide was pulverized in an argon atmosphere to obtain selenide powder with an average particle size of 80 μm. To this, Te7g, 76wt%,
5e-8b-In 21. Te at a rate of 24vt%
Powder (average particle size 100 μm) was added, pulverized and mixed for 60 minutes in cyclohexane using a ball mill, thoroughly dried, and hot press raw material powder (Te 75.Se
10. Sb IQ, In5 (11%)) was obtained. The obtained powder was packed into a rubber mold and cold isostatically pressed (CI).
Pressure molding was performed using P) at 5 ton/cj, and the resulting green compact was processed into a size of 152.4 mm φ x 30 mst, sufficiently dried, and then heated using a hot press in an argon atmosphere.

The molded body (H
, P, molded body) was obtained.

This molded body was cut using a wire electrical discharge machine, and
A target of 2.4u+φx5mm' was manufactured. As shown in Table 1, the target thus obtained had a density close to the theoretical density.

Example 2 In order to obtain a 30 kg ingot in a high frequency induction melting furnace, T
e 94.7wt%, Se 5. Argon gas 600Hg at a ratio of 3wt%, 450-500℃
The molten metal was cast into a carbon mold under an argon gas atmosphere, and the resulting ingot was crushed using a crusher to obtain alloy powder with an average particle size of 150 μm.

On the other hand, at a ratio of Se 50wt% and 5b50vt%,
A heating reaction was carried out at 400 to 500° C. for 5 hours in a quartz sealed tube, and the obtained selenide was pulverized in an argon atmosphere to obtain selenide powder with an average particle size of 80 μm.

Both selenide powders obtained in this way were mixed with Te-5e
89.86wt%, 5e-Sb 10. 14v
6 in cyclohexane using a ball mill at a rate of t%.
Finely pulverize and mix for 0 minutes, dry thoroughly, and prepare raw material powder for hot press (Te 80.Se 15.5b5 (11%)
) was obtained.

This was filled into a graphite mold of 21 (I--
The molded body (
H, P, molded body) were obtained.

This molded body was cut using a wire electric discharge machine, and
A target of 1 layer x 210m x 5-■t was manufactured. As shown in Table 1, the target thus obtained had a density close to the theoretical density.

Table-1 Density of hot press molded product [Unit: r/cd]

Claims (1)

[Scope of Claims] 1) One or more metals selected from the group consisting of titanium, silver, arsenic, lead, antimony, and indium are mixed with selenium or a selenium alloy, and the mixture is heated under vacuum or with an impurity such as argon, nitrogen, helium, etc. A heating reaction is carried out in an active gas atmosphere to form selenide, to which tellurium or tellurium alloy is added and pulverized and mixed in a non-oxidizing atmosphere.The resulting fine powder mixture is directly hot pressed or cold isostatically pressed. press(
1. A method for producing a sputtering target for optical recording, which comprises forming a green compact by CIP), followed by hot pressing to obtain a compact having a substantially uniform composition and approximately the same theoretical density. 2) The manufacturing method according to claim (1), in which tellurium or a tellurium alloy is added to several types of selenides, and the mixture is pulverized and mixed. 3) The manufacturing method according to claim (1) or (2), wherein tellurium or a tellurium alloy and selenide are pulverized and mixed in an organic solvent to an average particle size of 0.5 to 50 μm.