JPS595666B2 - sputtering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coaxial sputtering apparatus, and particularly to a sputtering apparatus characterized by a shutter mechanism.

A typical structure of a coaxial sputtering device is shown in FIG.

In the figure, 1 is a vacuum chamber whose inside is evacuated and atmospheric gas is introduced into the interior, 2 is a cylindrical target placed at the center of the vacuum chamber 1, and 3 is a substrate holder, which is used to hold a plurality of substrates. The holder 3 is arranged concentrically with respect to the cylindrical target 2, and a substrate 4 to be processed is attached to the surface of the holder 3.

A shutter 5 shields the target 2 during pre-sputtering, has a semicircular cross-sectional shape, and is rotatably disposed around the target 2.

6 is a shield.

In such an apparatus, during pre-sputtering, the shutter 5 is in the position shown by the solid line and shields the target 2, but during sputtering, the shutter 5 rotates in the direction of arrow a and moves to the position shown by the broken line, so that the target 2 is not sputtered. , a sputtered film is formed on the substrate 4 to be processed on the substrate holder 3.

However, in the one shown in Figure 1, the effective area of the target 2 to be sputtered is half of its surface area;
Accordingly, the number of substrates 4 to be processed on which sputtered films are formed is only half of the number of substrates 4 to be processed placed in the vacuum chamber 1, which does not result in an increase in the number of substrates to be processed. This means that even if the substrate holder 3 is revolved in the direction of the arrow b, the sputtered film formation speed will be slow and the throughput will not change. As a solution to these drawbacks, a solution as shown in the second figure has been proposed.

In this method, the substrate holder 3 is arranged concentrically with respect to the cylindrical target 2 in the vacuum chamber 1, and the substrate holder 3 is
It is constructed so that it can rotate as shown by arrow c.

Therefore, during pre-sputtering, the back surface of the substrate holder 3 faces the target 2, and during sputtering, the substrate holder 3 is reversed and a sputtered film is formed on the surface of the substrate 4 to be processed attached to the surface thereof. however,
In the one shown in FIG. 2, since the substrate holder 3 itself is also used as a shutter, the substrate 4 to be processed cannot be attached to both sides of the substrate holder 3, and this also has a limit on the amount of processing.

Furthermore, there is also a sputtering apparatus shown in FIG.

This is done by arranging a plurality of shutters 7 concentrically between the cylindrical target 2 and the substrate holder 3 in the vacuum chamber 1 to surround the target 2, and closing them as shown by the solid line during pre-sputtering, and closing them during sputtering. It is in the open state as shown by the broken line. According to this, by rotating the substrate holder 3 in the direction of the arrow d, the substrates 4 to be processed can be attached to both sides of the substrate holder 3, and the processing amount can be increased. However, since the shutter 7 is located between the target 2 and the substrate holder 3, the shutter 7 is exposed to plasma during sputtering, and the substances scattered from the shutter 7 adhere to the substrate 4 to be processed. A drawback is that it becomes difficult to obtain a sputtered film. Therefore, an object of the present invention is to provide a coaxial sputtering device having a novel shutter mechanism.

Another object of the present invention is to provide a coaxial sputtering device that can utilize the entire surface of a cylindrical target during sputtering and can form a sputtered film on a substrate to be processed that is arranged around the entire circumference of the target.

Hereinafter, regarding the sputtering device according to the present invention,
A detailed explanation will be given according to an illustrated embodiment.

FIG. 4 is a schematic plan view showing the main parts of a coaxial sputtering apparatus according to the present invention.

In FIG. 4, 11 is a cylindrical target placed at the center of the vacuum chamber, 12 is a substrate holder,
A plurality of substrate holders 12 are arranged concentrically around the target 11 and are configured to be rotatable as shown by arrows E and f, and a shutter 13 is provided at a right angle on the side surface of the substrate holder 12.

A substrate to be processed 14 on which a sputtered film is formed is attached to both surfaces of the substrate holder 12. The substrate holder 12 shown by the solid line is in a position facing the cylindrical target 11, which is the position during sputtering.

Further, the substrate holder 12 indicated by the broken line is positioned at right angles to the cylindrical target 11, and at this time, the main surface of the shutter 13 faces the cylindrical target 11, and the substrate holder 1
2 from the cylindrical target 11,
This is the position at the time of pre-sputtering. The position of the substrate holder 12 during sputtering is such that one main surface 12a of the substrate holder 12 faces the cylindrical target 11 in the illustrated state, but the other main surface 1 of the substrate holder 12
2b can also be opposed to the cylindrical target 11, and a sputtered film can be formed on the substrates 14 to be processed attached to both sides of the substrate holder 12. The sizes of the board holder 12 and the shutter 13 are as shown in the figure.
Although the width of the shutter 13 is smaller than the width of the substrate holder 12, at least the width of the shutter 13 is such that the substrate holder 12 is on the radial extension line of the cylindrical target 11.
It needs to be large enough so that it does not protrude from the outside.

In this embodiment, by lowering the gas pressure in the vacuum chamber during pre-sputtering, it is possible to reduce the amount of sputter particles that go around to the back side of the shutter 13, thereby suppressing adhesion of sputter particles to the substrate 14 to be processed. be able to.

If it is necessary to strictly suppress the sputter particles from going around to the substrate 14 to be processed during pre-sputtering, the embodiment shown in FIG. 5 is preferable. As is clear, when the substrate holder 12 is in the position shown by the broken line, the shutters 13 surround the cylindrical target 11 in a polygonal shape, and the major difference is that there is no gap between adjacent shutters 13. .

In the illustrated example, the shutters 13 have portions 13a that partially overlap with adjacent shutters 13 in order to more precisely suppress the gap between the shutters 13. The rest of the configuration is almost the same as that shown in FIG. 4, so a detailed explanation will be omitted.

FIG. 6 further shows another embodiment of the sputtering apparatus according to the present invention.

In FIG. 6, similar to the embodiment shown in FIG. 5, the shape of the shutter is characterized.

In other words, the structure shown in FIG. 6 was adopted against the following background.

In other words, as shown in FIG. 5, if the shape of the shutter 13 is large, when sputtering is performed with the shutter 13 open, a part of the shutter 13 will be located between the target 11 and the substrate holder 12. Moreover, the shutter 13 is positioned perpendicularly to the substrate holder 12, and in its positional relationship to the target 11, the shutter 13 is in a state of diagonally crossing the radial extension of the target.
Therefore, some of the spatter particles collide with the surface of the shutter 13 on the side closer to the target 11, and some of the collided spatter particles adhere to the substrate to be processed 14 attached to the substrate holder 12. This results in non-uniformity in the thickness of the sputtered film. FIG. 6 shows a solution to the above-mentioned problem, in which the shape of a part of the shutter, particularly the end of the shutter, is given a unique shape.

In other words, in the figure, when the shutter 13 is in the open state, the shutter 1 is located on the radial extension line of the target 11.
3 is located. Further, this shutter 13 is constructed so that there is no gap between adjacent shutters 13 when the shutter 13 is in the closed state, and furthermore, it is constructed so that it has a partially overlapping portion 13a. Note that the other configurations of the embodiment shown in FIG.
Since it is almost the same as the one shown in the figure, detailed explanation will be omitted.

Further, the shape of the shutter 13 is not limited to that shown in FIG. 6, but the shape is such that the end of the shutter 13 is located on the radial extension of the target 11 when the shutter 13 is opened. It is sufficient that the shutter 13 is in a position that shields the substrate holder 12 so that the substrate holder 12 is not located at least on the radial extension of the target 11 when the shutter 13 is in the closed state.

As is clear from the above embodiments, according to the configuration of the present invention, a plurality of substrate holders are arranged concentrically around a cylindrical target placed at a central position in a vacuum chamber. In the provided sputtering apparatus, the substrate holder is rotatable such that its main surface is located opposite to and perpendicular to the cylindrical target; A shutter is provided on the side surface of the substrate holder so that the substrate holder is shielded from the cylindrical target when the substrate holder is positioned perpendicular to the target. Therefore, during pre-sputtering, the substrate holder can be shielded from the target, and during sputtering, the substrate holder can be placed opposite to the target.

This means that the substrate holder is placed facing the entire circumference of the target during sputtering, so that the entire surface of the target contributes to the formation of the sputtered film and does not affect the throughput in any way. In addition, when sputtering occurs, the shutter moves away from the target, which reduces the probability that the shutter will be spattered, especially compared to the one shown in Figure 3, and it is less affected by being heated by radiant heat from the target during sputtering. Therefore, impurities are not mixed into the sputtered film, and a high quality sputtered film can be obtained.

[Brief explanation of the drawing]

1 to 3 are schematic plan views showing conventional examples of a conventional sputtering device, and FIGS. 4 to 6 are schematic plan views showing each embodiment of the sputtering device according to the present invention. 11... Cylindrical target, 12... Substrate holder, 13... Shutter.

Claims (1)

[Claims] 1. In a sputtering apparatus in which a plurality of substrate holders are provided concentrically around a cylindrical target with respect to a cylindrical target placed at a central position in a vacuum chamber, the substrate holder is arranged to The main surfaces thereof are located opposite to each other and are rotatable so that the main surfaces are located at right angles, and when the substrate holder is located at right angles to the cylindrical target, the substrate holder is shielded from the cylindrical target. A sputtering apparatus characterized in that a shutter is provided on a side surface of a substrate holder, as shown in FIG.