TWI387653B - Manufacturing method of noble metal sputtering target - Google Patents

Description

Method for manufacturing noble metal sputtering target

The present invention relates to a method of manufacturing a target, and more particularly to a method of manufacturing a noble metal-containing sputtering target.

The hard disk is a modern main device for storing a large amount of data, and the data is mainly a magnetic film recording layer stored on a hard disk. The magnetic film recording layer is mainly composed of a cobalt (Pt) noble metal cobalt (Co) group. alloy. It is known that the magnetic film recording layer is coated on a hard disk by a sputtering process using a sputtering target.

In the prior art, a cobalt chromium-ruthenium dioxide (CoCrPt-SiO ₂ ) film is the main material of a magnetic recording film of a high-capacity hard disk. Among them, since the SiO ₂ ceramic is contained, the powder metallurgy process is required to prepare the CoCrPt-SiO ₂ target, that is, the Co powder, the Cr powder, the Pt powder and the SiO ₂ powder are mixed well, or the CoCrPt prealloy powder is selected. After the SiO ₂ powder is thoroughly mixed, the target is shaped and densified by a hot press process or a hot press process.

The conventional powder mixing method is divided into dry mixed powder and wet mixed powder. The main difference between the two is whether or not the mixed powder is selected in the solution, but the metal powder should be overcome first regardless of the mixed powder method. The problem is that the specific gravity of the ceramic powder is very different and cannot be uniformly mixed.

1 shows the microstructure of a conventional CoCrPt-SiO ₂ target, wherein the particle having the largest particle size is Pt, and the deepest portion of the color is SiO ₂ . It can be clearly seen from the microstructure diagram of Fig. 1 (magnification 100 times) that the distribution of Co, Cr, Pt and SiO ₂ components in the conventional CoCrPt-SiO ₂ target is extremely uneven, that is, the conventional target The material manufacturing method does not uniformly mix Co powder, Cr powder, Pt powder and SiO ₂ powder.

Therefore, it is necessary to provide an innovative and progressive manufacturing method for noble metal-containing sputtering targets to solve the above problems.

The present invention provides a method for producing a noble metal-containing sputtering target, which comprises: (a) providing a precious metal powder and a ceramic powder; (b) performing the precious metal powder and the ceramic powder in a solvent. a first wet mixing step to form a noble metal-ceramic slurry, wherein the ceramic powder is bonded to the surface of the precious metal powder; (c) adding a magnetic metal powder to the precious metal-ceramic slurry for a second a wet mixing step to form a magnetic metal-precious metal-ceramic slurry; (d) drying the magnetic metal-precious metal-ceramic slurry to form a magnetic metal-precious metal-ceramic composite powder; and (e) forming and densifying The magnetic metal-precious metal-ceramic composite powder is formed to form a sputtering target containing a noble metal.

The manufacturing method of the present invention firstly uses the first wet mixing step to uniformly bond the ceramic powder having a lower specific gravity and higher hardness to the surface of the noble metal powder having a higher specific gravity and a lower hardness, and then the magnetic metal powder. The body is added to the precious metal-ceramic slurry, and then uniformly mixed in the second wet mixing step, and after the drying process, the composite powder containing the magnetic metal-precious metal-ceramic is obtained, and finally the forming and densification process is utilized. The magnetic metal-precious metal-ceramic composite powder is used to form a fine, uniform and dense noble metal-containing sputtering target, wherein the precious metal-containing target can be used for film sputtering in the magnetic recording industry, the photoelectric industry or the semiconductor industry. Plating process.

2 is a flow chart showing a method of manufacturing a noble metal-containing sputtering target of the present invention. First, referring to step S21, a noble metal powder and a ceramic powder are provided, and the purity of the powders is preferably greater than 99.5%. In this embodiment, the noble metal is platinum, and the purity of the platinum metal powder and the ceramic powder is greater than 99.95%.

In this embodiment, the ceramic powder system uses cerium oxide (SiO ₂ ), titanium dioxide (TiO ₂ ), cobalt monoxide (CoO), tantalum pentoxide (Ta ₂ O ₅ ), antimony trioxide (Y _{2 ).} O ₃ ) or bismuth pentoxide (Nb ₂ O ₅ ). Among them, the ceramic powder preferably has a particle diameter of 0.07 to 1.0 μm.

Referring to step S22, the ceramic powder and the precious metal powder are subjected to a first wet mixing step in a solvent (for example, water or alcohol) to form a noble metal-ceramic slurry. In the present embodiment, the first wet mixing step is carried out in a mixing device (for example, a ball mill). The ceramic powder having a higher hardness may be bonded to the surface of the noble metal powder having a lower hardness after the first wet mixing step (for example, the ceramic powder is set on the surface of the precious metal powder). Wherein, the first wet mixing step preferably has a mixing time of 0.5 to 4 hours.

Referring to step S23, a magnetic metal powder is added to the noble metal-ceramic slurry, and a second wet mixing step is performed to form a magnetic metal-precious metal-ceramic slurry. Wherein, the magnetic metal powder may be cobalt or cobalt chromium alloy, and the second wet mixing step preferably has a mixing time of 4 to 20 hours.

Referring to step S24, the magnetic metal-precious metal-ceramic slurry is dried to form a magnetic metal-precious metal-ceramic composite powder. In this embodiment, The magnetic metal-precious metal-ceramic slurry is dried by a vacuum drying method or an atmospheric drying method. The vacuum drying temperature is 80 ° C to 120 ° C, the vacuum drying time is 2 to 4 hours, the vacuum drying vacuum is less than 760 torr (torr); the atmospheric drying temperature is 100 ° C to 160 ° C, atmospheric drying The time is 4 to 6 hours.

Referring to step S25, the magnetic metal-precious metal-ceramic composite powder after molding and densification is mixed to form the noble metal-containing sputtering target of the present invention, wherein the noble metal-containing target of the present invention can be applied to the magnetic recording industry and the photoelectric industry. Or the thin film sputtering process of the semiconductor industry. In this embodiment, the forming and densification steps are performed by a hot pressing process or a hot isostatic pressing process, wherein the molding and densification temperature is 800 ° C to 1200 ° C, and molding is performed. And the densification time is 1 to 4 hours.

In the noble metal-containing sputtering target of the present invention, the ceramic powder preferably has a weight percentage of 5% to 12%, and the precious metal powder preferably has a weight percentage of 20% to 50%, and the remaining weight percentage is The content of magnetic metal powder. In this embodiment, the magnetic metal powder system is a cobalt chromium alloy, wherein the ceramic powder has a weight percentage of 5% to 12%, and the precious metal powder has a weight percentage of 20% to 50%, and the cobalt chromium alloy The weight percentage of chromium is 4% to 16%, and the remaining weight percentage is the weight percentage of cobalt of the cobalt chromium alloy.

The invention is illustrated by the following examples, which are not intended to be limited to the scope of the invention.

Example 1:

This example is exemplified by the production of a cobalt-chromium-platinum-niobium oxide (CoCrPt-SiO ₂ ) alloy sputtering target. First, platinum (Pt) powder and cerium oxide (SiO ₂ ) powder (particle size 0.25 μm) having a purity of up to 99.95% or more are provided. Next, the Pt powder and the SiO ₂ powder were placed in deionized water for a first wet mixing step for 2 hours to form a Pt-SiO ₂ slurry. Next, the Co powder and the Cr powder are added to the Pt-SiO ₂ slurry to perform a second wet mixing step for 18 hours to form a CoCrPt-SiO ₂ slurry, wherein the purity of the cobalt powder and the chromium powder is as high as 99.9%. the above. Next, the CoCrPt-SiO ₂ slurry was placed in an atmospheric oven for an atmospheric drying step in which the drying temperature was 160 ° C and the drying time was 6 hours. Finally, the dried CoCrPt-SiO ₂ powder is placed in a graphite mold, and the mixed powder is pressed into a target shape and the target is heated at a temperature of 1100 ° C for 4 hours. After densification, a fine, uniform CoCrPt-SiO ₂ target can be obtained. In the present example, the content of cobalt in the CoCrPt-SiO ₂ target prepared was 44% by weight (44 wt.%), the content of chromium was 4 wt.%, and the content of platinum was 45 wt.%, the content of cerium oxide is 7 wt.%.

Example 2:

This example is exemplified by the production of a cobalt-chromium-platinum-titanium dioxide (CoCrPt-TiO ₂ ) alloy sputtering target. First, platinum (Pt) powder and cerium dioxide (TiO ₂ ) powder (particle size 0.07 μm) having a purity of up to 99.95% or more are provided. Next, the Pt powder and the TiO ₂ powder were placed in an alcohol to carry out a first wet mixing step for 1 hour to form a Pt-TiO ₂ slurry. Next, the Co powder and the Cr powder are added to the Pt-TiO ₂ slurry for a second wet mixing step for 12 hours to form a CoCrPt-TiO ₂ slurry, wherein the purity of the cobalt powder and the chromium powder is as high as 99.9%. the above. Next, the CoCrPt-TiO ₂ slurry was placed in a vacuum oven, and a vacuum drying step was carried out at a vacuum of 76 torr, wherein the drying temperature was 80 ° C and the drying time was 2 hours. Finally, the dried CoCrPt-TiO ₂ powder was taken out, and after canning with stainless steel, the powder was pressed into a target shape and the target was heated at 800 ° C for 2 hours under heat equalization. After the material is densified, a fine and uniform CoCrPt-TiO ₂ target can be obtained. In the present example, the CoCrPt-TiO ₂ target prepared has a cobalt content of 48 wt.%, a chromium content of 13 wt.%, a platinum content of 31 wt.%, and a titanium dioxide content of 8 wt. .%.

Fig. 3 is a view showing the microstructure of a noble metal-containing sputtering target obtained by the method for producing a noble metal sputtering target of the present invention. It can be clearly seen from the microstructure diagram of Fig. 3 (magnification 100 times) that the magnetic metal, platinum metal and ceramic components in the precious metal sputtering target of the present invention are extremely uniformly distributed, that is, the precious metal splash of the present invention The plating target manufacturing method can uniformly mix the magnetic metal powder, the precious metal powder and the ceramic powder to form a fine, uniform and dense noble metal-containing sputtering target.

The manufacturing method of the present invention firstly uses the first wet mixing step to uniformly bond the ceramic powder having a lower specific gravity and higher hardness to the surface of the noble metal powder having a higher specific gravity and a lower hardness, and then the magnetic metal. The powder is added to the precious metal-ceramic slurry, and then uniformly mixed in the second wet mixing step, and after the drying process, the composite powder containing the magnetic metal-precious metal-ceramic is obtained, and finally the forming and densification process is utilized. The magnetic metal-precious metal-ceramic composite powder is used to form a fine, uniform and dense noble metal-containing sputtering target.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not limiting. this invention. Therefore, those skilled in the art can make modifications and changes to the above embodiments without departing from the spirit of the invention. The scope of the invention should be as set forth in the appended claims.

1 shows a microstructure of a conventional CoCrPt-SiO ₂ target; FIG. 2 shows a flow chart of a method for producing a noble metal-containing sputtering target of the present invention; and FIG. 3 shows a method for producing a precious metal-containing sputtering target of the present invention. The microstructure of the prepared noble metal-containing sputtering target.

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Claims (19)

A method for manufacturing a noble metal sputtering target, comprising the steps of: (a) providing a precious metal powder and a ceramic powder; (b) performing the first wet type of the precious metal powder and the ceramic powder in a solvent; a powder mixing step to form a noble metal-ceramic slurry, wherein the ceramic powder is bonded to the surface of the precious metal powder; (c) adding a magnetic metal powder to the noble metal-ceramic slurry for performing a second wet mixing powder a step of forming a magnetic metal-precious metal-ceramic slurry; (d) drying the magnetic metal-precious metal-ceramic slurry to form a magnetic metal-precious metal-ceramic composite powder; and (e) forming and densifying the magnetic metal - Precious metal-ceramic composite powder to form a sputter target containing precious metals. The method of claim 1, wherein in the step (a), the purity of the precious metal powder is greater than 99.5%. The manufacturing method of claim 1, wherein in the step (a), the noble metal is platinum. The manufacturing method of claim 1, wherein in the step (a), the ceramic powder system is cerium oxide (SiO ₂ ), titanium oxide (TiO ₂ ), cobalt monoxide (CoO), tantalum pentoxide (Ta ₂ O). ₅ ), antimony trioxide (Y ₂ O ₃ ) or antimony pentoxide (Nb ₂ O ₅ ). The manufacturing method of claim 1, wherein in the step (a), the ceramic powder has a particle diameter of 0.07 to 1.0 μm. The manufacturing method of claim 1, wherein the weight percentage of the ceramic powder It is 5% to 12%, and the weight percentage of the precious metal powder is 20% to 50%, and the remaining weight percentage is the magnetic metal powder content. The production method of claim 1, wherein water or alcohol is used as the solvent in the step (b). The manufacturing method of claim 1, wherein in the step (b), the mixing time of the first wet mixing step is 0.5 to 4 hours. The manufacturing method of claim 6, wherein in the step (c), the magnetic metal powder system is cobalt or a cobalt alloy. The manufacturing method of claim 9, wherein in the step (c), the cobalt alloy is a cobalt chromium alloy. The manufacturing method of claim 10, wherein in the step (c), the chromium chromium alloy has a chromium percentage of 4% to 16% by weight. The manufacturing method of claim 1, wherein in the step (c), the mixing time of the second wet mixing step is 4 to 20 hours. The manufacturing method of claim 1, wherein the slurry is dried in the step (d) by a vacuum drying method or an atmospheric drying method. The manufacturing method of claim 13, wherein in the step (d), the vacuum drying temperature is from 80 ° C to 120 ° C, and the vacuum drying time is from 2 to 4 hours. The manufacturing method of claim 13, wherein in the step (d), the temperature of the atmospheric drying is from 100 ° C to 160 ° C, and the drying time is from 4 to 6 hours. The manufacturing method of claim 14, wherein in the step (d), the degree of vacuum of the vacuum drying is less than 760 torr. The manufacturing method of claim 1, wherein the forming and densifying steps are carried out in the step (e) by a hot press or a hot press. The method of claim 17, wherein in the step (e), the molding and densification are carried out at a temperature of from 800 ° C to 1,200 ° C, and the molding and densification is carried out for a period of from 1 to 4 hours. The manufacturing method of claim 1, wherein the method for producing the noble metal-containing sputtering target is applied to a film sputtering process in the magnetic recording industry, the photovoltaic industry, or the semiconductor industry.