JPS60204878A - Sputtering target - Google Patents

Abstract

PURPOSE:To form thin films each having a uniform thickness distribution by sputtering for a long period by providing a trapezoidal cross-section to a target and fixing the target so that the major side confronts a surface to be processed. CONSTITUTION:A trapezoidal cross-section is provided to a target 2', and the target 2' is fixed on a high frequency electrode 1 so that the major side confronts a surface to be processed. The face of the target 2' confronting the surface to be processed has a larger surface area, and the angle theta of each angular part 2a' formed by the major and minor sides is about 15-50 deg.. Even when the consumption of the arget 2' proceeds during sputtering, the face of the target 2' confronting the surface to be processed maintains its flatness for a long period, so the uniformity of a thin film in thickness can be kept.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to sputtering targets.

In particular, it concerns the structure of the target material.

[Background of the invention]

Conventional 1 For example, in a thin film forming method using radio frequency sputtering, it is known that if the same sputtering target is used as the base material of the thin film to form a thin film over a long period of time, the sputtering target will wear out. There is.

That is, as shown in the cross-sectional view in FIG.
-The electric field is concentrated near shield 3.

As shown in FIG. 2, the target 2 is not uniformly consumed and deformed into an arc shape as shown in FIG. 2 by repeated sputtering. As a result, the scattering direction 4 of particles scattered from the target 2 changes during sputtering, resulting in a problem that the uniformity of the film thickness distribution of the deposited thin film decreases.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a sputtering target that can form a thin film with a uniform film thickness distribution during long-term sputtering of the target.

[Summary of the invention]

In order to achieve such an object, the present invention provides a target having a trapezoidal cross section and a button device such that the longer side faces the surface to be processed.

[Embodiments of the invention]

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

Figure 3 is a cross-sectional configuration diagram of a main part showing an example of a sputtering target according to the present invention. The same parts as in the previous figures are given the same reference numerals. In the figure, target 2' is
The surface facing the machined surface has a long side.

The surface to be scissored to the high-frequency electrode 1 has short sides and a trapezoidal cross section. t,b In this case,
This target 2' has a larger surface area on the surface to be processed than the surface on the high-frequency electrode 1 side. Further, this target 2' is configured such that the angle θ of a corner 21' formed by a long side and a short side is set in a range of about 15 degrees to about 60 degrees when viewed in cross section.

According to such a configuration, during sputtering, the electric field is concentrated at the peripheral corner 2a' shown in the figure, so even if the wear progresses due to repeated sputtering, the target 2' The surface to be machined did not have an arcuate shape as in the past, and could always maintain flatness over a long period of time. It was. When the relationship between the angle θ of the peripheral corner 21' of the target 2' and the number of times of sputtering to obtain a uniform film thickness on the surface to be processed was measured, the results shown in FIG. 5 were obtained. That is, in the same figure, target 2'
The angle θ of the peripheral corner 2' of is initially set to about 15 degrees to about 50 degrees.
By setting the temperature within the range of 0°, the uniformity of the film thickness could be maintained for about three times as long as in the conventional case (approximately 0°).

〔Effect of the invention〕

As explained above, according to the sputtering target according to the present invention, it is possible to maintain the uniformity of the thin film thickness for several times longer with the same target compared to the conventional method, thereby significantly improving the manufacturing yield. You can get an extremely excellent effect of being able to do things yourself.

[Brief explanation of drawings]

Figures 1 and 2 are sectional views of essential parts for explaining an example of a conventional sputtering target, and Figures 3 and 4 are sectional views of main parts.
The figure is a sectional view of a main part for explaining an example of a sputtering target according to the present invention. FIG. 5 is a diagram showing the relationship between the angle of the peripheral corner of the target and the duration of film thickness uniformity. 1...High frequency electrode, 2'...Target. 2 a/... peripheral corner, 3... earth shield, 4... particle. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) A sputtering target characterized by having a trapezoidal shape in which the sputtering surface facing the surface to be processed has a long side when viewed from a cross-sectional shape, and the electrode mounting surface side has a short side. 2. The corner of the trapezoidal shape on the sputtering surface side is 15
2. The sputtering target according to claim 1, wherein the sputtering target is set in a range of 50 degrees to 50 degrees.