JPH0273971A - Sputtering target - Google Patents

Abstract

PURPOSE:To improve the bonding strength of a backing plate to an Fe alloy target by forming a film of a metal having satisfactory wettability with solder on the rear side of the target to be bonded to the backing plate. CONSTITUTION:When a backing plate is bonded to an alloy target consisting of a specified amt. of one or more among Si, Al and Ga and the balance Fe with additive elements, a film of a metal having satisfactory wettability with solder, e.g., Cu is formed on the rear side of the target to be bonded to the backing plate by ion plating or other method in >=1mum thickness and the backing plate is bonded to the rear side with solder such as Sn-Pb. The cracking and peeling of the resulting sputtering target are prevented and the reliability of the target is improved.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to an F
e-8i series, FeAQ series, Fe-AQ-8i series, Fe-
The present invention relates to sputtering targets such as 8i-Ga type.

[Prior Art] In recent years, the technology of using magnetic thin films as magnetic heads has progressed rapidly, and in particular, the coercive force of recording media has increased in order to improve recording density. Also, the magnetic herad gap is becoming narrower. For this reason, it is desired that the magnetic head material has a high magnetic flux density, and from this point of view various Fe-based alloys are being studied.

Especially Fe-8i system, Fe-8i-Afl system, Fe5i-
Since Ga-based materials have high magnetic permeability, composite heads made by combining them with ferrite have been put into practical use. These thin films are usually formed by sputtering, but it is generally known that the state of the created film varies greatly depending on the characteristics of the target used for sputtering. Therefore, in the manufacture of targets, it is important to strictly control not only the composition but also the purity, crystal grain size, internal strain, etc.

On the other hand, the target must be cooled to prevent its temperature from rising during sputtering. Generally, as shown in Figure 1, the target is soldered to a Cu plate called a backing plate, and then the sputtering device It often has a structure in which it is attached to and cooled b).

[Problems to be Solved by the Invention] In such a structure, if the backing plate and target are not strongly bonded, the target will become abnormally high temperature during sputtering, which may change the properties of the formed film, or in severe cases. The target and backing plate may separate during sputtering, and the target may crack due to poor cooling.

By the way, when the Fe alloy contains easily oxidizable elements such as AQ, Si, and Ga, an extremely thin oxide film is formed on the target surface, resulting in poor solder wettability and extremely difficult adhesion. For this reason, when these alloy targets are directly soldered to the backing plate, the above-mentioned problems occur frequently, posing an extremely serious problem in industry.

The purpose of the present invention is to overcome the above-mentioned drawbacks of sputtering targets that contain elements that are easily oxidized such as Si, Al, and Ga, with the remainder mainly consisting of Fe and additive elements, and to create a new sputtering target that has extremely high bonding strength between the target and the backing plate. To provide a sputtering target.

[Means for Solving the Problems] That is, the first aspect of the present invention is a backing plate and solder of an alloy target containing 1 wt % or more of at least one of Si, Al, and Ga, and the balance being Fe and additional elements. This is a sputtering target characterized by having one or more layers of metal film with good wettability with solder formed on the side to be bonded using solder. This results in significantly better adhesion between the target and the backing plate. In this case, the additive element mentioned in claim 1 may be, for example, Ru or Cr for improving corrosion resistance, or Ti or Zr for refining grains or improving wear resistance. Yes, but not particularly limited. Further, the reason why one or more of Si, Al, and Ga is set to 1 wt% or more is that if it is less than 1 wt%, the solder wettability is relatively good, so that the effect of the present invention is not significant. Also, the solder here is 5n-
Pb, Sn-Ag, In-8n, In, In-8n-C
d, etc., but is not particularly limited to these component systems. The reason why the thickness of the metal film is set to be 1- or more is that if it is less than 1-, the metal film and the solder react with each other during soldering, and the metal film may peel off.

The second aspect of the present invention is that the metal film having good wettability with the solder is C
The sputtering target according to claim 1 is characterized in that Cu is used as the metal film because it has extremely good adhesion with various solders, It also has the advantage of being easy to apply a film.

A third aspect of the present invention is the sputtering target according to claim 1 or 2, characterized in that a surface on which a metal film is to be formed on the target is previously made to have a surface roughness of 2S or more. Here, the reason why the surface roughness for forming the metal film on the target is set to 2S or higher = 4 is because if it is less than 2S, the bonding force of the metal film to the target is weak and the metal film and target may peel off. .

[Example] Hereinafter, the present invention will be explained in detail based on Examples.

Example 1 A target having the alloy composition shown in Table 1 was prepared. All targets were disk-shaped with an outer diameter of 100 mm and a thickness of 5 m. The sputtering surface of each target is 2S, and
After the surface to be bonded to the backing plate was finished to 68, six capes of Cu were formed on the surface to be bonded to the backing plate by ion blasting. (Table 1 No. 6
) Furthermore, the target and backing plate were bonded using 50% 5n-Pb solder, sputtering was performed with an input power of 6 W/a, and a 5 mm x 10 ++ a test piece for peeling test was cut out using the method shown in Figure 2. I did a peel test. The strength is shown in the right column of Table 1.

Comparative materials without Cu film (Table 1 N011-5)
Tests were also conducted for the following results: Table 1, Table 2, Table 3. As is clear from Table 1, the bonding strength of the inventive example with the Cu film formed was high, and the conventional example of NO12
, 3 cracked during sputtering, whereas No. 1 of the invention example
, 7.8 was found to have extremely high reliability as a target without cracking.

Example 2 Table 2 shows the results of peel strength tests using various Cu film thicknesses on targets of 7% 5i-10% Ga-7,4% Ru-remaining Fe. Other conditions are the same as in Example 1. As is clear from the table, it can be seen that when the Cu film becomes 1- or more, the peeling strength increases significantly.

Example 3 Table 3 shows 10.3%5i-6%A Q -0, 7T i
The graph shows the change in peeling strength when the type of metal film formed on the O,3Ru-remaining Fe target is changed to Cu, Fe, and Ni. Comparisons were made with the film thicknesses kept constant at 5-5, and it can be seen that among these, Cu exhibits the highest peeling strength.

Example 4 FIG. 2 shows the relationship between the surface roughness of the surface of the target on which the metal film is to be formed and the adhesive strength. 9.6 as a target
%5i-5,6%AQ-0.3%Ru-0.7%Ti-
The remaining Fe was used and Cu was used as the metal film. As is clear from the figure, when the surface roughness of the target is 2S or more, the adhesive strength is significantly large.

[Effect of the invention] According to the present invention, cracking of the target occurred due to heating of the solder part, but since the bonding strength of the adhesive part has increased, cracking and peeling of the sputtering target are completely eliminated, and the reliability of the target is greatly improved. improves.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sputtering target according to the present invention, and FIG. 2 is a diagram showing the relationship between target surface roughness and adhesive strength. 1 Varnish Battering Target 2: Packing Plate. 3: Metal film 4: Solder

Claims (1)

[Claims] 1) 1wt of at least one of Si, Al, and Ga;
% or more, with the balance being Fe and additive elements, and a metal film having a thickness of 1 μm or more and having good wettability with solder is formed on the side of the alloy target that is bonded to the backing plate using solder. target. 2) The sputtering target according to claim 1, wherein the metal film having good wettability with solder is Cu. 3) 2S in advance on the surface on which the metal film will be formed on the target.
The sputtering target according to claim 1 or 2, characterized by having the above surface roughness.