JPS60234967A - Target for sputtering - Google Patents

Abstract

PURPOSE:To make the ratio between components in a thin film formed on a substrate by sputtering nearly uniform over the whole film by blending plural elements in different ratios in the central and peripheral parts of a target. CONSTITUTION:An alloy, a sintered body or the like consisting of plural elements is formed into a circular platelike body and used as a target 1. At this time, an element which does not stick well to the substrate is blended with other element in different ratios in the central and peripheral parts 2, 3 of the target 1. For example, when a thin film consisting of Mo and Si is formed on a silicon substrate with an MoSi2 target, the percentage of Si is made higher in the central part of the target than in the peripheral part so as to make the percentage of Si in the resulting thin film nearly uniform over the whole film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sputtering target made of an alloy, a sintered body, etc. consisting of two or more component elements.

Conventionally, when forming a thin film made of one or more elements on the surface of a substrate by sputtering, the process is carried out by placing a target c of Mo5il, for example, in a vacuum chamber a, facing the substrate such as a silicon wafer, as shown in Figure 1. Generally speaking, the thin film attached to the surface of the substrate is MoF as shown in Figure 2.
Although i is almost uniformly distributed, the component ratio of Si is small in the center of the substrate, making it impossible to obtain a homogeneous thin film. The reason why thin films with such uneven component ratios are formed is thought to be due to the fact that when sputtered, the ejecting direction of the elements differs depending on the species, and the deviation angle of the direction when colliding with gas atoms differs. , normally the component ratio of 81 may deviate by more than 5% at the center of the board and at the outer periphery.
This makes it unsuitable as a substrate for I.

The present invention aims to provide a target suitable for forming a thin film on a substrate in which a plurality of elements are distributed almost uniformly. In a target such as an alloy made of the plurality of elements arranged facing each other, the target is
The central portion and the outer peripheral portion thereof are formed with different proportions of elements that have poor adhesion to the substrate.

An embodiment of the present invention will be explained with reference to FIG.
indicates Kugela)k, which is obtained by forming an alloy or sintered body made of multiple elements into a circular plate-like body.

When the target (1) is provided in a vacuum chamber facing the substrate as shown in FIG. 1 and subjected to sputtering, its constituent elements adhere to the surface of the substrate in the form of a thin film. In this case, the central part (2) of the target (1) and its outer peripheral part (3)
) By changing the compounding ratio of elements that have poor adhesion to the substrate, it is possible to obtain a good, almost uniform thin film in which the component ratio of the thin film formed on the substrate does not differ much between the central part and the outer peripheral part of the substrate. It will be done.

When forming a thin film made of silicon substrates VCMo and SI, a target made of MoSi2 is used, but in this case there is a problem because the Si component ratio in the central part of the substrate is smaller than in the outer periphery as described above. In the central part (2) of the Si Mira target 1), its outer peripheral part (
By blending more than the blending ratio of 3), the Si component ratio of the thin film on the substrate can be made almost uniform throughout.

As a means of changing the blending ratio of component elements between the central portion (2) and the outer circumferential portion (3), in the embodiment, an annular outer circumferential portion (3) is used.
and a central part (2) that fits inside the circular hole (3a), and 8 parts outside the core (for example, the blending ratio of Mo and 81 is 1:2 for 31VC, but the central part (2) Then]: 2.
5. Note that the number of component elements may be three or more.

In this way, according to the present invention, since the compounding ratio of multiple elements is changed between the central part of the target and its outer peripheral part, the composition ratio of the thin film formed on the substrate by sputtering can be made almost uniform throughout. It has effects such as being particularly convenient for manufacturing KVLSI substrates.

[Brief explanation of drawings]

Figure 1 is a cross-sectional diagram of a general sputtering device, Figure 2
Fig. 3 is a cross-sectional perspective view of a section of an embodiment of the present invention. (1) Target (2) Central part ( 3)
・・・Outer part

Claims (1)

[Claims] In a target such as an alloy made of a plurality of elements, which is placed facing the substrate to form a thin film made of a plurality of elements on the surface of the substrate by scattering, Sputtering targets are formed by forming different blending ratios of elements that have poor adhesion to the substrate.