JPS634450B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sputtering apparatus, and particularly to a sputtering apparatus that forms a film of uniform quality.

Conventionally, there has been a device of this type as shown in FIG. FIG. 1 is a block diagram showing a conventional in-line planar magnetron sputtering apparatus. In the figure, 1 is a sputtering room in which sputtering is performed, 2 is an exhaust device that exhausts the sputtering room 1, 3 is an anode electrode, 4 is a target, 5 is a target support part that holds the target 4, and 6 is the surface of the target 4 facing the anode electrode 3. 7 is a substrate on which a film is formed by sputtering, 8 is a tray that holds the substrate 7, and 9 is a shield member for exposing the target support part 5 and shielding the anode electrode 3 from the target 4. A running path provided to allow movement between
0 is a power supply, 11 is a stocker room, and 12 is a valve between the sputtering room 1 and the stocker room 11.

Next, the operation will be explained. To perform sputtering, after evacuating the inside of the sputtering room 1 to a predetermined vacuum and filling it with an appropriate gas pressure using an inert gas such as Ar gas, direct current or alternating current power is applied between the anode electrode 3 and the target 4. is applied to generate a discharge and turn Ar atoms into plasma. The ionized Ar ⁺ atoms collide with the target 4, which is negatively applied to the anode electrode, and eject the target atoms, which adhere to the substrate 7 to form a film. The substrate 7 is placed on the tray 8,
Following the travel path 9, the anode electrode 3 and the target 4
The film is formed by moving between the two at a certain speed. The board 7 is taken in and taken out in the stocker room 11. Using such an in-line planar magnetron sputtering device that moves on the running path 9 to take out and take out the sample substrate 7, the SiO ₂ film formed on the Si wafer is sequentially coated with hydrofluoric acid from the surface. FIG. 2 shows the relationship between the depth from the surface layer and the etching rate at that point when etching is performed using a mixed solution of ammonium fluoride. FIG. 2 is a characteristic diagram showing the relationship between the depth from the surface layer of a SiO ₂ film formed using a conventional sputtering apparatus and the etching rate at that point. The numbers shown in the figure are the Ar pressure during sputtering. According to FIG. 2, it can be seen that the surface layer has a high etching rate, and the etching rate decreases toward the inside of the film. It is thought that the size of the etching rate corresponds to the density of the SiO ₂ film; the surface layer with a high etching rate has a less dense SiO ₂ film, and the inner layer with a slower etching rate has a less dense layer. It is thought that a SiO ₂ film with a high degree of oxidation is formed.

Figure 3 shows the board being held still on the target.
This is a characteristic diagram showing the relationship between the deposition position, etching rate, and deposition rate when a SiO ₂ film is deposited.
The white circles indicate the film formation rate, and the black circles indicate the etching rate.

In FIG. 3, the SiO ₂ film formed on the center of the target 4 exhibits a nearly constant etching rate, but the SiO ₂ film formed on the edge of the target 4 and above the periphery of the target 4 shows an almost constant etching rate. It shows high etching speed.

In a normal film forming process using an in-line sputtering device, the substrate 7 held on the tray 8 moves over the target 4 from one end to the other as shown in FIG. Perform membrane. Therefore, the film that was formed when the substrate 7 was on the end of the target 4 and the surrounding area of the target 4 is attached to the surface layer of the film. In Figure 2, the surface layer has a high etching rate.
This is thought to be the reason why the SiO ₂ film was observed. In addition, from Figure 3, when calculating the thickness of the surface layer with a high etching rate and low density, the film becomes a film with a low density up to about 10% of the film thickness from the surface. It is possible that Since the substrate 7 moves over the target 4 from one end to the other, a film with a high etching rate and low density is formed at the start of film formation, similar to that observed in the surface layer. become.

In other words, the SiO ₂ film treated with this type of equipment is
It is thought that the film has a sandwich structure in which a less dense SiO ₂ film is formed at the top and bottom of the film, and a more dense SiO ₂ film is formed at the center of the film.

When microfabrication of a SiO ₂ film in this state is performed using photolithography, it is difficult to perform microfabrication with accurate dimensions because the etching speed differs between the upper and lower parts of the film and the inside. I had a lot of flaws.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional method. It is an object of the present invention to provide a sputtering apparatus capable of forming a film of uniform film quality by providing a shield member that prevents atoms sputtered from an oblique direction from adhering to a substrate.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a sectional view of the main parts of an in-line planar magnetron sputtering apparatus according to an embodiment of the present invention. In the figure, 13 indicates atoms sputtered from an oblique direction with respect to the direction perpendicular to the film formation surface of the substrate 7, which is provided between the substrate 7 that has moved between the target 4 and the anode electrode 3, and the target 4. This is a target shielding member that prevents the target from adhering to the substrate. In the sputtering apparatus having such a configuration, since the shield member 13 is provided to prevent diagonal sputtering from the target, the sputtering of the substrate 7, which is performed when the substrate 7 is on the edge of the target 4 and the periphery of the target 4, is provided. It is possible to prevent atoms that have been sputtered from oblique directions to the direction perpendicular to the film formation surface from adhering to the substrate. Therefore, as shown in FIG. The formation of a SiO ₂ film with a high etching rate and low density formed above the periphery of the target 4 is reduced, resulting in a highly dense and homogeneous film formed above the center of the target 4. It is possible to form a film.

In the above embodiment, the shield member 6 of the target mounting part and the shield member 13 for preventing sputtering diagonally from the target are provided separately. A shield member 13 may be provided overlappingly with the shield member 13 exposed to prevent diagonal sputtering from the target.

In addition, in the above embodiment, the case where the target 4 is located below the substrate 7 was explained, but the target 4 is located above the substrate 7 and the film is formed toward the substrate 7 located below. It may also be a sputtering device.

As described above, according to the present invention, a target shield is provided between the target and the substrate that has moved between the target and the anode electrode to prevent sputtering in a direction perpendicular to the direction perpendicular to the film formation surface of the substrate. Since the member is provided, there is an effect that a film having a homogeneous quality can be obtained.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing a conventional in-line planar magnetron sputtering device, and Figure 2 is the relationship between the depth from the surface layer of the SiO ₂ film formed with the conventional sputtering device and the etching rate at that point. Figure 3 is a characteristic diagram showing the relationship between the deposition position, etching rate, and deposition rate when a SiO ₂ film is deposited with the substrate stationary on the target. 1 is a sectional view of the main parts of an in-win type planar magnetron sputtering apparatus according to an embodiment of the present invention. In the figure, 1 is a sputtering room, 2 is an exhaust system, 3 is an anode electrode, 4 is a target, 5 is a target support part, 6 is a shield member for the target support part, 7 is a substrate, 9 is a running path, and 13 is a part of the sputtering from the target. This is a shield member that prevents diagonal sputtering. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A sputtering room filled with an inert gas and used for sputtering, an exhaust device for evacuating this sputtering room, an anode electrode and a target installed in the sputtering room and used to apply a voltage to discharge, a target support section for holding this target, and the above-mentioned A shielding member for exposing the surface of the target facing the anode electrode and shielding the target support portion from discharge, and a substrate on which a film is formed by sputtering are provided so as to be movable between the target and the anode electrode. A shield for the target is formed between the substrate that has moved between the target and the anode electrode and the target to prevent sputtering in a direction perpendicular to the direction perpendicular to the film formation surface of the substrate. Sputtering equipment with parts.