JPS6067668A - Sputtering apparatus - Google Patents

Abstract

PURPOSE:To form a thin film having a uniform film thickness even to a large substrate to be coated, by arranging a plurality of magnets to the back surface of a sputtering target. CONSTITUTION:A plurality of ring shaped magnets 11, 12 are arranged to the back surface of a target 5 in a concentric circular form from the center point of the target 5 so as to generate a plurality of ring shaped etched region to the surface of a sputtering target 5 in a concentric circular form or a plurality of rod like magnets are arranged to the target 5 from the center point thereof in a concentric circular and radial form.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an improved sputtering apparatus for forming a thin film on the surface of a substrate.

(bl) Prior art and problems In general, spackling equipment is used only for cathodes (hereinafter referred to as
This device collides gas ions with a target (called a target) to make the target material into atoms and deposit it on the surface of the substrate to which the anode is attached, forming a thin film on the surface.

Such sputtering equipment is used, for example, when manufacturing semiconductor devices, and is an essential equipment for forming aluminum electrode films and insulating films. The reason for this is that films deposited by the sppack method have advantages over films deposited by other methods, such as a film with uniform crystal grains and ease of depositing alloy films. In particular, it is widely used for depositing aluminum electrode films. In addition, the ease of in-line (automation) is a major advantage in terms of mass production.

Incidentally, there are various types of sputtering apparatuses, but when forming a film on a semiconductor substrate (semiconductor wafer), a spray type sputtering apparatus is used.

On the other hand, as semiconductor substrates become increasingly larger in diameter with the advancement of semiconductor devices, variations in the thickness of films deposited using such a subanotaring device also increase.

By the way, there is a tendency to process each wafer in order to avoid increasing the size of the entire device, but when using a normal disk-shaped targeter, if the substrate to be adhered to becomes large,
It is necessary to make the thickness of the deposited film uniform by widening the distance between the negative and positive electrodes, but this has the disadvantage of increasing the size of the sputtering apparatus and also reduces the efficiency of use of the target.

tel OBJECT OF THE INVENTION The present invention solves these drawbacks and proposes a spackling device that is compact and capable of forming a thin film of uniform thickness even on a large substrate. It is something.

fd+ Structure of the Invention The object of the invention is to form the Kugela 1 to
A sputtering device in which a plurality of magnets are disposed on the back surface of the target, for example, a sputtering device in which a plurality of ring-shaped magnets are disposed concentrically from the center point of the target on the back surface of the target, or a sputtering device in which a plurality of bar-shaped magnets are disposed on the back surface of the target. This can be achieved by a spackling device arranged concentrically and radially from the target midpoint.

(el　Embodiments of the invention An embodiment will be described in detail below with reference to one drawing.

FIG. 1 shows a schematic cross-sectional view of an example of a conventional sputtering apparatus.
is held, and a target 5 is connected to the cathode 4 in parallel to it.
is disposed, evacuated to a vacuum through the exhaust port 6, and argon (Ar) gas is introduced through the gas inflow lower part. The degree of pressure reduction is 1
0-2 to 10-3 Torr, frequency 13. '56
High frequency power 8 of MIIZ is applied to the cathode 4, and the adherend substrate 3 is
A target material is deposited on top. In that case, one magnet 9 is placed on the back surface of the target, and the electron density in the electrode space is increased by the magnetic lines of force of the magnet, and the Ar+ ion density is increased, so the sputtering efficiency is increased several times. . As the magnet 9, for example, a ring-shaped permanent magnet as shown in FIG. 2 is used. In this way, the magnet 9 has the effect of improving productivity and making the spackling device extremely efficient.

However, the presence of the magnet 9 tends to make the thickness of the deposited film non-uniform when the substrate to be deposited or the target becomes large, and this situation will be explained with reference to FIG. Figure 3 shows data for an example in which an aluminum film was deposited on a semiconductor substrate using a 4-inch diameter semiconductor substrate as the deposition substrate 3 and an 8-inch diameter aluminum (8I) plate as the target 5; (X) indicates the distance from the center point of the adherend substrate, and the dark blue axis indicates the film thickness.
The distance between the adherend substrate and target is 4Qw+, and the same figure (b
l is 60mm, and in the same figure (C1 is 80mm). From this, it can be seen that the most appropriate distance between the substrate and the target is 60n. However, with this equipment, 6-inch wafers can be uniformly Even in the same figure (bl) where the distance is the most appropriate, the thickness of the deposited film is thinner at the outer periphery. Therefore, the target is made even larger and the gap between the deposited substrate and the target (distance III) is further increased. However, this would increase the size of the entire sputtering device, making it extremely inefficient.
As shown in the figure, the ratio of the etched surface portion of the target 5 with the magnet 9 close to its back surface becomes small, resulting in poor usage efficiency and increased cost.

The present invention provides a sputtering apparatus that eliminates such drawbacks, and FIG. 5 shows a schematic sectional view of a 10-inch sputtering apparatus as an embodiment of the present invention. The same members as in FIG. 1 are given the same reference numerals.
-5 and are arranged concentrically. Figure 6 shows magnet 1
1.12 is shown in a perspective view. FIG. 7 shows data of an example in which an aluminum film was deposited using this spackling apparatus under the same conditions as in FIG. 3. In conventional equipment, the most appropriate distance between the deposition substrate and the target, that is, the gap at which the most uniform deposition film is formed, is 90 to 150 mm.
am, but because the inner ring-shaped magnet 11 is provided, the gap can be set to 60 to 90 mm (D gap).The data is shown in Fig. 7. The distance between the target and the target is 401. fb) is 60
N, same figure (C1 is 80fi.

fdl in the figure shows the case of 100u+, and the most uniform film thickness is obtained when the distance is 60 m, and the distribution becomes worse as the distance increases.

The greatest advantage of the present invention is that a uniform film thickness can be obtained due to the short distance, and the target usage efficiency is also improved. As described above, in the conventional device using one ring-shaped magnet as shown in FIG. 1, a uniform film thickness can be obtained when the distance between the two electrodes is 90 to 150 mm. FIG. 7 shows that in a device using two ring-shaped magnets as shown in the figure, a uniform film thickness can be obtained when the distance between the image electrodes is set to 60 to 90 mm.

In addition, the target has a plurality of etched areas (erosion areas) formed in the state shown in FIG. 8, and wears out evenly, so that usage efficiency is improved.

Furthermore, if the number of ring-shaped magnets is increased instead of just two, a more significant effect can be obtained. Moreover, the same effect can be obtained by arranging two sets of bar-shaped magnets radially from the center of the target as shown in FIG. 9 instead of using the ring-shaped magnets. , (fl Effects of the Invention As is clear from the above explanation, according to the present invention, the distance between both electrodes is shortened to make the film thickness uniform, so the sputtering device becomes smaller and the sputtering efficiency increases. Rise,
Moreover, the efficiency of using Kugera 1- is improved. Therefore, the sputtering apparatus according to the present invention can be incorporated into an automated process of semiconductor manufacturing to be useful for high-speed processing of the process.

Note that although the above example is explained using the RF sputtering method using a high frequency power source, it goes without saying that the sputtering method using a DC power source is also similar.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view of a conventional spuck device, Fig. 2 is a perspective view of its magnet, Fig. 3 is data obtained from the device shown in Fig. 1, Fig. 4 is a sectional view of a conventional target after use, Fifth
Figure 6 is a schematic cross-sectional view of the sputtering apparatus according to the present invention, Figure 6 is a perspective view of its magnet, Figure 7 is data obtained from the apparatus shown in Figure 5, and Figure 8 is a cross-section of the target according to the present invention after use. 9 are perspective views of other magnet arrangement states according to the present invention. In the figure, 1 is a reaction chamber, 2 is an anode, and 3 is a substrate. 4 is a cathode, 5 is a cooget, 6 is an exhaust port, 7 is a gas inlet, 8 is a high frequency power, and 9, 11, and 12 are targets. 1st tube middle 1■ →

Claims (2)

[Claims] (1) A sputtering apparatus characterized in that a plurality of magnets are disposed on the back surface of the sputtering target so that etched regions are formed in the shape of a plurality of concentric rings on the surface of the sputtering target. (2) On the back surface of the target, a plurality of ring-shaped magnets are arranged concentrically from the center point of the target, or a plurality of bar-shaped magnets are arranged concentrically and radially from the center point of the target. Characteristic claim 1
The sputtering apparatus described in .