JPH04325672A - Sputtering device - Google Patents

Abstract

PURPOSE:To provide a sputtering device in which films having narrow thickness distribution can be formed with relatively small targets at a low cost as a sputtering device used as a film forming means. CONSTITUTION:The interval between the center of a target 9 and the center of rotation of a pallet 2 is made different from that between the center of a target 10 and the center of rotation of the pallet 2. The thickness distributions of films formed on substrates with the targets 9,10 become different from each other but the thickness distributions of the resulting films can be synthetically narrowed by offsetting.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus used as a means for forming thin films.

0002

2. Description of the Related Art In recent years, sputtering is the most commonly used method for forming thin films, and is used in the manufacture of various devices.

A conventional sputtering apparatus will be explained below. FIG. 2 shows a conventional sputtering apparatus. In FIG. 2, 11 is a vacuum chamber. A pallet 12 is connected to a motor 18 via a rotating shaft 17. 13 and 14 are substrates, and a substrate holder 15
, 16 to the pallet 12. 19,
Reference numeral 20 denotes a target, which is installed at a position facing the substrates 13 and 14. In reality, the number of targets is generally about 4 and the number of substrates is about 10.
This figure is omitted for simplicity.

The sputtering apparatus constructed as described above is intended to improve the efficiency of target use and shorten the film forming time per substrate. ,20
Film formation is performed using both at the same time.

[0005]

[Problems to be Solved by the Invention] In the conventional configuration described above, the distances between the centers of the targets 19 and 20 and the rotation axis of the pallet 12 are approximately equal, and the distance between the centers of the substrates 13 and 14 and the rotation center of the pallet 12 is approximately the same. is almost in agreement. In normal sputtering, the film formation rate is fastest directly above the center of the target. Therefore, as shown in FIG. 3, the film thickness distribution on the substrates 13 and 14 is thick near the center of the substrate and thinner at the outer periphery. When it is necessary to form a film accurately and uniformly over the entire surface of a substrate, as in the case of an optical disk, a large target is required for the substrate, resulting in an increase in cost.

The present invention solves the above-mentioned conventional problems, and aims to provide a sputtering apparatus capable of forming a film with a small thickness distribution at low cost using a relatively small target.

[0007]

In order to achieve this object, the sputtering apparatus of the present invention is configured such that at least one of the plurality of targets has a different distance from the rotation center of the pallet.

[0008]

[Operation] With this configuration, the relative position of the substrate and target differs for each target that the substrate passes as the pallet rotates during film formation, and the film thickness distribution on the substrate also differs. This cancels out the film thickness distribution in each target, and it is possible to reduce the film thickness distribution on the substrate as a whole without using a large target.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a sputtering apparatus in one embodiment of the present invention. In Figure 1,
1 is a vacuum chamber. A pallet 2 is connected to a motor 8 via a rotating shaft 7. 3 and 4 are substrates;
It is attached to the pallet 2 by substrate holders 5 and 6. Targets 9 and 10 are installed at positions facing the substrates 3 and 4. In reality, the number of targets is four and the number of substrates is eight, but they are omitted in this figure for the sake of simplicity.

When the distance between the rotation center of the pallet and the center of the substrate is R, and the radius of the substrate is r, the distances a and b between the rotation center of the pallet and the centers of the targets 9 and 10 are approximately (Equation 1), There is a relationship as shown in (Equation 2). Further, the positional relationship between the rotation centers of a target (not shown) and the pallet is the same as that of the target 9 on one side and the target 10 on the other side.

[0011]

[Math 1]

0012

[Equation 2] In the sputtering apparatus configured as above, by forming a film by using targets 9 and 10 or all targets simultaneously while rotating the pallet, the film thickness distribution in each target is offset. ,
As shown in FIG. 4, overall, the film thickness distribution on the substrate becomes smaller.

[0013] By providing a mechanism for rotating the substrate as the pallet rotates, the film thickness distribution on the substrate can be further reduced.

[0014]

Effects of the Invention As described above, the present invention has a structure in which at least one of the plurality of targets has a different distance from the rotation center of the pallet, thereby reducing costs by using a relatively small target. This makes it possible to realize an excellent sputtering device that can form a film with a small thickness distribution.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a sputtering apparatus in an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional sputtering apparatus.

FIG. 3 is a graph showing a film thickness distribution on a substrate when a film is formed using a conventional sputtering apparatus.

FIG. 4 is a graph showing a film thickness distribution on a substrate when a film is formed using a sputtering apparatus in an example of the present invention.

[Explanation of symbols]

1,11 Vacuum chamber 2,12 Palette 3, 4, 13, 14 Board 5, 6, 15, 16　Substrate holder 7, 17 Rotation axis 8, 18 Motor 9,10,19,20 Target

Claims (2)

[Claims] 1. A sputtering apparatus that performs film formation by simultaneously using a plurality of targets installed in the same vacuum chamber while rotating a pallet on which a plurality of substrates are mounted, wherein at least one target is attached to the pallet. A sputtering device whose distance from the center of rotation of the target is different from that of other targets. 2. The sputtering apparatus according to claim 1, further comprising a mechanism for rotating the substrate as the pallet rotates.