JPS60181268A - Sputtering target - Google Patents

Abstract

PURPOSE:To extend the life of a disc-shaped sputtering target and to reduce the cost thereof by constituting the target of a central part and a toric peripheral part where consumption is heavy and making the peripheral part exchangeable. CONSTITUTION:A target 10 to be used for sputtering is constituted of the 1st target 10a consisting of a base body part having a large diameter D2 and the central part having a small diameter D1 and the toric 2nd target 10b fitted to the periphery of the central part. The 1st and 2nd targets 10a, 10b are of course made of the material having the same quality and both targets 10a, 10b are united to one body by means of screws or pins made of the material having the same quality. The diameter D1 in the central part of the 1st target 10a is made 0.4-0.8 times the diameter D2 of the 2nd target 10b. The 2nd target 10b of the circumferential part where consumption by the sputtering operation is heavy is exchangeable and therefore the life over the entire part of the target is extended and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a sputtering target, and particularly to the structure of the target.

[Background of the invention]

Conventionally, a target used for sputtering is an integral disk having a predetermined composition and a constant thickness. As is well known, sputtering is performed by colliding ions with a target and ejecting molecules on the target surface.

However, the release of molecules from the target surface is not performed uniformly over the entire surface of the target, but is extremely intense in a certain region, that is, in the periphery of the disk. Therefore, as shown in the cross-sectional view of FIG. 1, the wear of the target 1 is more significant in the peripheral portion 1b than in the central portion 1a. When the peripheral portion 1b of the target 1 shown by the dotted line in the figure is consumed in this way, the thickness and quality of the deposited film become uneven, which is a practical disadvantage. The target 1 has to be replaced with a flat portion 1C on the surface. This problem is particularly frequent in the case of single-wafer processing sputtering, and is a cause of increased manufacturing costs.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a sputtering target that reduces manufacturing costs.

[Summary of the invention]

In order to achieve this purpose, the present invention divides a sputtering target into a uniformly small consumption area and a large consumption area, which are made of the same composition material, and are combined and integrated, so that only the large consumption area can be replaced. It is composed of

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings.

FIGS. 2(a) and 2(b) are a cross-sectional configuration diagram and a plan view showing an example of a sputtering target according to the present invention. In the same figure, the target 10 has a disk-shaped first disk whose central portion and base portion have diameters of h small and large, respectively.
A second target 10b having an annular shape fitted to the peripheral portion of the first target (A) 10a.
The first target 10a and the second target 10b are both made of, for example, Ni-F.
They are made of an e-alloy material and are combined and integrated with screws, pins, etc. made of the same member (not shown).

In other words, the first target layer ZO as a uniform minute consumption area
A and a second target 10b as a mass consumption area are formed in two parts, and the second target 10b is configured to be replaceable with a screw or pin.

Next, a detailed explanation will be given using a specific example.

First, the diameter Dl of the first target 10H of the target 10 is 100 mm, the total thickness Tl is 8 mm, and the diameter Ih of the second target 10b is 209 mm.

The thickness T2 was 5 mm, and both surfaces were made uniform and flat. Then, using this target 10, a film having a thickness of about 2.0 μm was continuously formed by RF sputtering. FIG. 3 shows the relationship between the number of depositions, film thickness variations, and wear of the target 10 in this case. As is clear from the figure, after the number of sputtering is about 300, the variation in film thickness becomes large as shown in characteristic I), and after about 60
Approximately 0 times and 3 times it will be approximately doubled. On the other hand, the wear of the target 10 is about 600 sputtering cycles, and the first target (uniform wear area) 10a has a wear of about 0.5 m as shown in characteristic 1a.
m is 2 to 2.5 mm in the second target (mass consumption area) 10b, as shown in characteristic 1b, and reaches about 4 to 5 times that of the first target (uniform consumption area) 10a. .

Here, only the second target (10b) disposed on the peripheral side of the target 10 is replaced with a new one to make the upper surface uniformly planar, and then the same sputtering as described above is repeated to increase the number of sputtering times. When we investigated the relationship between thickness variations and target wear, we obtained exactly the same results as in FIG. 3.

As is clear from the above configuration, if the target 10 is divided into two parts and only the large consumption area is replaced according to the amount of consumption, the target 10 will be 4 to
It has a lifespan about 5 times longer and is extremely cost effective.

The present invention is to divide the target into two parts and replace the peripheral parts that are severely worn out, but the important point is to always make the material composition of the replaced parts the same, which is important in the manufacture of the target. Manufactured from the same base material. At this time, since the peripheral portion of the target is replaced, a large base material is required. For this purpose, as shown in FIG. 4, the second target 10b in FIG. 2 is further divided into three parts, a third target 10bl, a fourth target 10b
The same results as in the case of FIG. 3 were obtained even when the structure was composed of 1Qbs (2 and 5). In addition, here 3
Although it is divided into two parts, it goes without saying that the same effect can be obtained by dividing it into two or four parts or more.

〔Effect of the invention〕

As explained above, according to the present invention, the target can be divided into multiple parts and only the parts that are severely worn out can be replaced, so the cost of the target itself can be reduced.
Therefore, an extremely excellent effect can be obtained in that manufacturing costs can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an example of a conventional sputtering target, FIG. 2(a), Φ) is a sectional view of a main part showing an example of a sputtering target according to the present invention
FIG. 3 is a plan view of the same, and FIG. 3 is a diagram showing the relationship between film thickness variation and target wear thickness with respect to the number of sputtering operations. FIG. 4 is a plan view showing another embodiment of the present invention. 10 lives...sputtering target, 10a...
・First target), 10b...-Second target, 10bl...e Third target, 1Qb2 @
...Fourth target, 10b8...Fifth target. 71

Claims (1)

[Claims] 1. A sputtering target characterized by being made of the same composition material and divided into a uniform micro-consumed region and a large-scale consumable region, and integrally constructed by combining the two regions. 2. The sputtering target according to claim 1, wherein the minute consumption area is a disc-shaped body, and the massive consumption area is a toric body. 3. The diameter of the disk-shaped body is 04 to 04 of the diameter of the toric body.
The sputtering target according to claim 2, wherein the sputtering target is 0.8 times.