JPS62149866A - Target for sputtering - Google Patents

Abstract

PURPOSE:To permit stable sputtering vapor deposition for a long period of time by packing a powdery target material into a tray-shaped vessel having ruggedness on a base and executing sputtering vapor deposition. CONSTITUTION:The powdery target material 2 (zinc sulfide, etc.) is packed by a pressure into the tray-shaped vessel 1 having ruggedness on the base. Such target material 2 is fixed on a cathode and the cathode is cooled with water. High-frequency electric power is impressed to the cathode and the sputtering vapor deposition is executed in an Ar atmosphere. The roughness of the ruggedness of the tray-shaped vessel 1 is effective at >=50mu and <=5mm. The packing pressure of the material 2 is preferably >=0.1kg/cm<2> and the tray- shaped vessel 1 is formed of one kind among copper, stainless steel, carbon and quartz. The generation of cracks on the surface of the material 2 and the floating of the target material from the tray-shaped vessel 1 are prevented and the stable sputtering vapor deposition is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sputtering target, and more particularly to a highly stable sputtering target when sputtering powdered materials.

Conventional technology Conventionally, when forming a thin film on a substrate by sputter deposition of powdered material, the powdered material is filled into a dish-shaped container made of 1 ml of stainless steel or quartz, and the sputtering apparatus uses the container as a target. sputter deposition was performed in a rare gas such as argon. (Japanese Unexamined Patent Publication No. 59-66390) Problems to be Solved by the Invention However, when a powder material is sputtered for a long time using such a dish-shaped container, cracks occur on the target surface, and the dish-shaped container The bottom of the container may be sputtered, or loose plate-shaped powder material may rise from the dish-shaped container.
There was a problem that the matching state and sputtering speed changed.

Therefore, an object of the present invention is to provide a target for powder materials with excellent stability.

Means for Solving the Problems In order to achieve this object, the sputtering target of the present invention is a dish-shaped container having an uneven bottom surface filled with powdered target material.

As a result, in the present invention, the powder enters the recesses of the dish-shaped container and the convex parts enter the powder material, so that the adhesion between the powder and the dish-shaped container or the thermal conductivity is increased, and the surface of the powder material target is improved. It is thought that this prevents cracking and lifting from the dish-shaped container, making stable sputtering possible over a long period of time.

Example FIG. 1 shows a sputtering target of the present invention.

The figure (&) is a sectional view of the container filled with the target material, and the figure (b) is a plan view thereof. In the same figure,
1 is a dish-shaped container made of stainless steel, and its size is 12
It is a rectangle of 5×375ff. 2 is a powdered target material filled in a dish-shaped container.

FIG. 2 is a partially enlarged sectional view of a container filled with target material.

In the figure, the thickness T of the dish-shaped container 1 is 10 pieces, and the depth D is 5 pieces.
It was set as Fff.

Furthermore, by machining the bottom surface of the dish-shaped container 1, its width W
A concave portion with a depth H of one bird was provided. This dish-shaped container is filled with powder target material 2 made of zinc sulfide with a particle size of about 5 μm under pressure, and the pressure at the time of filling is 1 ook kg.
/cA Toshida.

This target was fixed on the cathode of a sputtering device, the cathode was water-cooled, a high frequency power of 1 W/ci was applied, and 1×1O
Sputter deposition was performed in an Ar atmosphere of −2 Torr. Opposite the target surface, 501 from the target surface
It was possible to form a zinc sulfide thin film on a substrate placed at a distance of M at a rate of 500 people/min. At this time, even if sputter deposition was performed for 10 hours, no cracks occurred on the target surface or the powder target material rose from the dish-shaped container, and sputter deposition could be performed stably from beginning to end.

Using a conventional target, that is, a dish-shaped container with no uneven bottom surface filled with zinc sulfide powder under pressure,
When sputter deposition was performed under the same conditions, cracks appeared on the target surface after about 30 minutes, and after about 2 hours of sputter deposition, the target material rose from the dish-shaped container, making stable sputter deposition impossible.

In this example, the roughness of the unevenness on the bottom surface of the dish-shaped container was taken as one factor, but a great effect was obtained when the roughness was 50 microns or more. Although the effect can be observed even when the roughness is 5 or more, it is not practical because the thickness of the dish-shaped container needs to be increased. In this example, a matrix-like groove-like concave portion is formed, but it is clear that other shapes are also effective as long as the concavities and convexities improve adhesion. Also, as a forming method, sandblasting the bottom surface of the dish-shaped container to give it a roughness of about 100 microns was also effective. In addition, it was also possible to form irregularities by etching.

By applying pressure when filling the powdered target material into a dish-shaped container, stable sputter deposition could be performed without the target powder becoming red-hot even when the discharge power was 2 W/c7J or more. The filling pressure is o, 1kg/
ci or higher was appropriate. In other words, if it is less than 0.1 kg/cd, the target surface is likely to become red hot when the discharge power is increased, and fine powder may fly up during vacuuming and adhere to the substrate surface, which is undesirable. Ta.

As for the material of the dish-shaped container, in addition to stainless steel, copper and carbon 2 quartz were used, and stable sputter deposition over a long period of time was possible.

It goes without saying that the present invention can be practiced with materials other than zinc sulfide as the sputtering material. In particular, when a high-purity thin film is required, there is no need to use a sintered body as the sputtering material, making it possible to prevent impurities from entering the sintered body during firing, making it easy to sputter-deposit a highly pure thin film. We were able to.

Effects of the Invention As described above, according to the present invention, even if a powder material is used as a target, sputter deposition can be performed stably over a long period of time, and the practical effects are excellent.

[Brief explanation of drawings]

FIG. 1(a) shows a diagram for explaining one embodiment of the present invention.
A sectional view of the target, FIG. 2B is a front view thereof, and FIG. 2 is an enlarged sectional view of the same portion. 1...Dish-shaped container, 2...Powdered target material. Name of agent Patent attorney Toshio Nakao and one other person (b
) Broom 2 diagram?

Claims (4)

[Claims] (1) A sputtering target characterized in that a powdered target material is filled in a dish-shaped container having an uneven bottom. (2) The sputtering target according to claim 1, wherein the roughness of the unevenness is 50 microns or more and 5 mm or less. (3) The filling pressure of powdered target material is 0.1 kg/
The sputtering target according to claim 1, wherein the sputtering target has a diameter of cm^2 or more. (4) The sputtering target according to claim 1, wherein the dish-shaped container is made of one of copper, stainless steel, carbon, or quartz.