JPS63162863A - Manufacture of chromium target for sputtering - Google Patents

Abstract

PURPOSE:To manufacture a uniform Cr target having high purity and stable quality, by filling a Cr powder into a metallic vessel and hermetically vacuum- sealing the above to apply hot isostatic pressing and by subjecting the resulting high-density compact to slicing and then to the prescribed machining. CONSTITUTION:The Cr powder is filled into the metallic vessel of stainless steel, etc., to undergo hermetical vacuum sealing. At this time, it is preferable that the metallic vessel filled with the Cr powder is reduced to vacuum while being heated up to about 400-600 deg.C, and proper degree of vacuum is about 1X10<-4>-1X10<-5>Torr. Subsequently, the above hermetically vacuum-sealed vessel is subjected to omnidirectionally uniform heating and pressurizing treatment at about 1,100-1,300 deg.C under a pressure of about 800-1,200kg/cm<2> by means of hot isostatic pressing. The resulting uniform and high-density Cr compact is sliced into a sheet of the prescribed thickness, which is machined to be formed into the Cr target for sputtering.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is used to form a chromium thin film by sputtering, which is used as a photomask material, a hard disk recording medium, a thermal printer electrode, and a dry plating material. The present invention relates to a method for manufacturing a chromium target.

[Conventional technology]

Chromium thin films formed by the sputtering method are currently in practical use as photomask materials, hard disk recording media, thermal printer electrodes, dry plating materials, and multilayer wiring base materials. The target is a melting and casting method in which lumpy chromium is melted in a vacuum arc melting furnace and the resulting molten metal is poured into a mold to form a plate-shaped chromium ingot. There is a powder sintering method in which a sintered body is formed by hot pressing, which is compressed from two directions at the bottom, or the Cr powder is placed in a stainless steel can, vacuum degassed, the Cr powder is soaked together with the stainless steel can, and then hot-sintered. It is manufactured by a hot rolling method in which the Cr powder is rolled into a sintered body.

[Problem that the invention seeks to solve]

However, in the above-mentioned melting and casting method, the amount of ingot obtained is reduced by half because chromium is violently volatilized during melting.
The yield is extremely low, and in the powder sintering method described above, the sintered body is manufactured by exposing the Cr powder to high temperature in a press container and pressurizing it from two directions, so the dimensions are limited to the dimensions of the press container. In addition, the sintered body may be contaminated by the press container or oxidized by residual oxygen, and the density of the sintered body may be uneven due to volatilization of the adsorbed gas. Furthermore, the hot rolling method described above has poor productivity because it is not possible to produce a large number of sintered bodies at once. Therefore, it is difficult to mass-produce homogeneous targets with stable quality using any of the above methods. Moreover, when a sputtering film is formed using the target obtained as a result, there is a problem that variations occur in film thickness, surface smoothness, and electrical characteristics.

[Findings based on research]

In view of this situation, the inventors of the present invention have conducted various studies and found that (1) Cr powder is packed in a metal container such as a stainless steel can, and the container is vacuum-sealed. The molded product obtained by uniformly heating and pressurizing a container in all directions using hot isostatic pressing does not contain adsorbed gas, has uniform density, is homogeneous, and is According to hydrostatic pressing (HIP), for example, width: 500 mm x length = 600 to 800 mm x thickness: 40
It is possible to produce molded bodies of various sizes, including those as large as 0. Therefore, by slicing a particularly large molded body, a large number of homogeneous large-sized plates can be obtained at once. Therefore, a homogeneous and large-sized target can be efficiently manufactured; (2) when vacuum sealing is performed, the metal container filled with Cr powder is evacuated while being heated;
Since gases such as oxygen, hydrogen, and nitrogen interposed between the Cr powder particles in the metal container are more completely removed,
We have discovered that a chromium target with even fewer impurities can be obtained.

[Means for solving problems]

This invention was invented based on the above knowledge, and provides a highly productive method for manufacturing a chromium target for sputtering that can manufacture a homogeneous chromium target of high purity and stable quality even in a large size. Cr powder is packed in a metal container, which is vacuum-sealed by heating and vacuuming as needed.
This vacuum-sealed container is subjected to uniform heating and pressure treatment in all directions using a hot isostatic press to form the Cr powder into a high-density homogeneous molded body, and then the molded body taken out from the container is placed in a predetermined shape. The method is characterized in that after slicing into thick plates, these plates are machined and used as sputtering targets.

[Detailed description of the invention]

1.0r powder In this invention, C produced by various methods is used.
Although Cr powder can be used, generally Cr powder with particle size: 40-250μ, produced by electrolytic chromium stamping, is used.

2. Vacuum sealing The above Cr powder is placed in a metal container, for example, in a leaky shape,
After filling the inside of a stainless steel can with a stainless steel pipe vertically attached to the center of the main body, the inside of the stainless steel can is usually evacuated for 5 to 10 hours to maintain a vacuum level, for example. : IX10
Vacuum at ~lXl0 Torrt.

By this evacuation, gaseous impurities such as O2, N2, and N2 that were present between the Cr powder particles are usually almost completely removed.
When vacuuming is performed while heating to 600°C, the degree of vacuum inside the container reaches 1 × 10 Torr, and the gaseous impurities are completely removed. to heat the Cr powder.

After the degree of vacuum within the stainless steel can reaches the above value, the base of the stainless steel tube is heated and pressed with a gas burner, thereby vacuum-sealing the Cr powder inside the stainless steel can.

3. Hot isostatic press (H-P) As mentioned above, the metal container in which the Cr powder is vacuum-sealed is placed in the pressure vessel of the hot isostatic press equipment.
Usually temperature: 1100-1300℃ and pressure crab 80
0 to 1200 for 30 to 180 minutes under 9/Crrt2, whereby the particles of the Cr powder are fused together without any gaps and transformed into a high-density homogeneous molded body.

4. Cutting and machining of molded body The molded body formed by hot isostatic pressing is removed from the metal container by scraping the metal container with a shaver, for example, and then the molded body is is cut, for example, by a Pantone machine, into a plate with a thickness of usually 6 to 10 mm, and then this plate is processed with a rotary surface or a plane grinding plate to finish it into a target with a predetermined shape and dimensions. It will be done.

[Examples and effects based on the examples]

Next, the present invention will be explained with reference to examples.

Wall thickness: 2B, and internal length: zoomxx width: 2
In the center of a rectangular parallelepiped stainless steel can body with a space of 50 m x height: 600 Ig, outer diameter = 12 m x length: 50
0 Mt
Filled with 299.9% purity Cr powder with 0μm,
Next, while heating this Cr powder to a temperature of 400°C,
By evacuating the inside of the stainless steel can for 8 hours through the stainless steel tube, the degree of vacuum is reduced to I x 10".
After raising the temperature to Torr, the base of the stainless steel pipe was heated and pressed with a gas burner, and the Cr powder was vacuum-sealed inside the stainless steel can.

Next, after putting the Cr powder vacuum-packed in the stainless steel can into the pressure vessel of the hot isostatic press,
The atmosphere in this pressure vessel was maintained at a temperature of 1100° C. and a pressure of 1000 kg/CrIL2 for 90 minutes to convert the Cr powder into a compact having a relative density of 100%.

After that, shave the stainless steel can that has been cooled to room temperature.
Remove it and take out the molded body having the dimensions of Length: 18 Qrut x Width: 225 MX Height: 54 C)ul, and cut this molded body into a thin plate with a thickness of 28 B along the height direction using Pantone. After cutting the body into 16 pieces, these plates were machined using a milling cutter and a rotary surface to a thickness of 26 mm x length = 530 mm x width: 21 mm.
A total of 16 targets with a size of 5 mm were produced.

Next, the densities of 16 samples cut out from arbitrary locations on each of the targets produced in this way were measured, and Pb, All, Cu, Fe, 0,
When the content of impurities such as C was investigated by instrumental analysis, no difference was observed in the density and the above impurity content in any of the samples, and it was found that all targets were homogeneous in these respects.

〔Effect of the invention〕

As is clear from the above description, in the present invention, the Cr powder is vacuum-sealed in a metal container and subjected to uniform heating and pressure treatment in all directions by hot isostatic pressing. , PI), AX, cu, Fe, 0,
A high-density, homogeneous molded body that is neither contaminated with impurities such as C nor caused by thermal distortion or processing distortion can be obtained, and the target is manufactured by slicing such a molded body. Therefore, according to the present invention, various excellent effects such as being able to efficiently produce targets with excellent purity, homogeneity, and stable quality, even large targets can be obtained.

Claims (2)

[Claims] (1) Fill a metal container with Cr powder, vacuum-seal the container, and apply uniform heating and pressure treatment in all directions using hot isostatic pressing to the vacuum-sealed container to make the Cr powder into a high-density, homogeneous material. The method is characterized in that the molded body is formed into a molded body, and then the molded body taken out from the container is sliced into plate bodies of a predetermined thickness, and then these plate bodies are subjected to mechanical processing to be used as a target for sputtering. A method for manufacturing a chrome target for sputtering. (2) During the vacuum sealing, the metal container filled with Cr powder is evacuated while being heated.
A manufacturing method according to claim (1).