JPH04365858A - Vapor deposition target of sputtering system for film formation - Google Patents

Abstract

PURPOSE:To provide the composite target constituted in such a manner that a vapor deposited film having extremely high uniformity in both of compsn. and characteristics in all parts is easily obtd. if this target is used at the time of forming the film by a sputtering method using the vapor deposition source of the sputtering system even when the thin film having the compsn. contg. plural elements has the element constitution ratios at which a single phase does not exist. CONSTITUTION:The auxiliary targets 2, 3 suppressed in area per 1 piece respectively uniformly to <=100mm<2> are arranged and fixed onto the surface of the main target 1 by evenly dispersing the targets to the respective parts on the main target surface in such a manner that the height of the auxiliary target surfaces is <=1/30 the distance between electrodes at the time of electric discharging in a sputtering stage if the auxiliary target surfaces project from the main target surface.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a process of forming a thin film having an element composition ratio in which no single phase exists, for example, for magnetic heads and magneto-optical recording media, by sputtering, and is suitable as a deposition source target. The present invention relates to a sputtering type evaporation source target for films.

0002

BACKGROUND OF THE INVENTION In recent years, there has been an increase in the number of products that require the formation of thin films having elemental composition ratios in which no single phase exists. For example, in the field of magnetic heads, the main component is Fe or Co, to which Nb, Zr, Ta, Hf, C, etc. are added, and in the field of magneto-optical recording, the main component is Fe and Tb.
, Nd, Co, etc., is required to be formed into a film so that the composition does not vary depending on the location. In general, sputtering is a suitable method for forming such thin films, but even when the composition ratio of elements does not exist in a single phase, the composition ratio of multiple elements in the completed deposited film is uniform everywhere. It was not necessarily easy to form a film to achieve this.

[0003] Various techniques for forming this type of thin film have been proposed in the past;
Publication No. 272 discloses a composite target made of two or more metal materials, in which a recess is provided on the surface of a base material, that is, a main target made of one metal material, and another metal material is placed in the recess as a sub-target. It is disclosed that it is formed by being fitted and fixed so that the surface is flat.

0004

[Problem to be solved by the invention] However, including the above,
With conventional techniques, although it is possible to sputter multiple elements at the same time, it is difficult to obtain a sputtered film with a uniform composition because each part made of a different material has a relatively large surface area.

[0005] The present invention provides a film-forming method that can easily form a thin film with a uniform composition in each part by a sputtering method even when the composition ratio of elements is such that a single phase does not exist. The purpose of the present invention is to provide a sputtering deposition source target.

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, when a film having an element composition ratio in which no single phase exists is formed by a vapor deposition method using a sputtering method vapor deposition source, The target for sputtering the deposition material for film formation is a so-called composite target in which many sub-targets made of sub-components with a small proportion of ingredients and having a smaller area than the main target are dispersed on the main target surface made of the main component. Furthermore, the area of each sub-target was uniformly set to 100 mm 2 or less, and the sub-targets were evenly distributed in each part over the entire surface of the main target. In order to evenly distribute a large number of relatively small sub-targets on the main target surface as described above, the actual work is to first prepare thin plate-shaped small pieces of the sub-component that meet the above conditions. Produced in large numbers,
It is relatively easy to uniformly distribute and paste this onto the main target surface. In this case, the sub-target surface will protrude more than the main target surface, but in that case, the height of the protrusion of the sub-target is
It was decided to keep the distance between the electrodes at least 1/30 of the distance between the electrodes during discharge in the sputtering process, which is approximately equal to the distance between the main target surface and the film-forming substrate surface.

[0007]

[Operation] By doing the above, the surface areas of multiple types of targets, each made of different elements, are all relatively small and are evenly distributed over the entire surface of the target, so a film can be formed by vapor deposition. The composition of the thin film was
It has good uniformity. When sputtering deposited film components from a target by electric discharge, if the surface of the target, which serves as one electrode, is uneven, there will be areas where the electric field strength is strong and areas where it is weak, and the sputtering speed will vary depending on the location. However, as long as the above conditions are followed, there is no problem according to the inventor's experiments. In addition, when pasting, adhesives suitable for such work are commercially available, and even if they adhere to and stain the target surface during pasting work, they can be easily removed and the surface can be cleaned. can.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in more detail below with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a plan view of a conventional example showing an example of a conventional evaporation source target used in a sputtering method. Targets 2 and 3 are sub-targets each made of a different element.

In the embodiment of the present invention shown in FIG. 1, sub-targets 2 and 3 made of different materials each have an area of about 25 mm 2 and are attached to the surface of the main target 1. Further, in the conventional example shown for reference in FIG. 2, sub-targets 2 and 3 each made of a different material and having an area of about 110 mm2 are pasted on the main target 1.

FIG. 3 shows a sputtered film formed under the same sputtering conditions using the composite target according to the embodiment of the present invention shown in FIG. 1 and the conventional composite target shown as the conventional example in FIG. In the drawings of both examples of the vapor deposited film, the vapor deposited film composition components A, B, and C at mutually corresponding parts indicated by numerals 4, 5, and 6, respectively (however, A is the main component and B
, C is a comparison diagram showing the composition ratios of subcomponents). From this figure, it can be seen that when the composite target according to the present invention is used, the uniformity of the composition is far more improved than when the conventional composite target is used. The diameter of the entire target was approximately 150 mm, the substrate on which the thin film was to be formed was approximately square, measuring 50 mm x 50 mm, and the distance between the electrodes was approximately 30 mm, and discharge was performed in argon gas.

Further, the present inventors have obtained important knowledge by applying the present invention to the formation of a magnetic film which is a main part of a magnetic head, which will be explained in detail below with reference to FIG. The magnetic film, which is the main part of the magnetic head, is made of FeMC (where M is T
The composite target of the present invention example shown in FIG. 1 and the composite target of the present invention example shown in FIG. A film was formed by sputtering using the conventional composite target shown in Figure 3 under the same conditions. Figure 4 shows
The magnetic properties ( FIG. In the conventional example, the variation in magnetic properties depending on the location is quite large, and the properties are not very good depending on the location, whereas in the example of the present invention, there is no variation in the magnetic property depending on the location, and the magnetic properties of those locations are not so good. The characteristics are excellent everywhere.

In FIGS. 3 and 4, the conventional example is shown as having different types of sub-targets arranged in rows in the vertical direction, but the size of the sub-targets and the distance from the main target surface When the protrusion height, etc. did not meet the conditions of the present invention, even if only the arrangement was improved uniformly in each part, deviations in component composition and magnetic properties were still observed depending on the location.

It can be seen from FIGS. 3 and 4 that the use of the composite target according to the present invention is extremely effective for forming thin films by sputtering. As mentioned above, the experimental results shown are for the composition FeTaC, but FeMC, CoMC, and FeCoMC, which are composed of Fe, Co, and various carbides (where M is T
It has been confirmed that any of the following is similarly effective.

The inventors also found that the probability that C is sputtered and scattered from the target approximately follows Gauss's law.
In other words, we obtained the knowledge that there is a high probability that the light will be incident at almost right angles. This makes the present invention particularly effective for sputtering targets containing C.

[0016]

As explained above, according to the present invention, a thin film having a composition containing multiple elements can be formed by vapor deposition using a sputtering vapor deposition source, even if the element composition ratio does not include a single phase. By using it as a target during formation, it is possible to easily mass-produce products with extremely high homogeneity without deviation in the composition of each part. Moreover, it is particularly effective when using a target containing C.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a plan view of an example of a composite target according to the prior art.

FIG. 3 is a comparative diagram showing the component ratios of the compositions of the sputter-deposited films in corresponding parts of sputter-deposited films formed under the same conditions using the targets of the embodiment of the present invention and the conventional example.

FIG. 4 is a comparative diagram of the magnetic properties of an example of the present invention and a magnetic thin film formed using a conventional target having the same composition as that of the example at corresponding parts.

[Explanation of symbols]

1...Main target, 2, 3...Secondary target, 4
, 5, 6... Mutually corresponding parts of the thin film formed by sputtering using the composite target of the present invention example and the conventional example composite target, A... Element of main target, B, C... Element of sub target.

Claims (2)

[Claims] [Claim 1] When forming a film having an element composition ratio in which no single phase exists by sputtering using a sputtering method vapor deposition source, the target to which the film-forming vapor deposition material is sputtered is A so-called composite target is constructed by dispersing a large number of sub-targets that are made of sub-components with a small component ratio and have a smaller area than the main target on the main target surface, and furthermore, the area of each sub-target is made uniform. A sputtering type evaporation source target for film formation, characterized in that the main target has a diameter of 100 mm2 or less and is evenly distributed in each part over the entire surface of the main target. 2. The sub-target surface according to claim 1, wherein when the sub-target surface protrudes beyond the main target surface, its height is set to 1/30 or less of the distance between the electrodes during discharge in the sputtering process. sputtering method evaporation source target for film formation.