JPH0544029A - Magnetron sputtering method and device - Google Patents

Abstract

PURPOSE:To suppress changes of conditions in film formation due to the erosion of a target and to enable stable film formation for a long time. CONSTITUTION:When a magnetic field is formed on the surface of a target 1 to increase plasma density and the surface of the target 1 is eroded by magnetron sputtering, lines 3 of magnetic force in the magnetic field are generated along the surface shape of the target 1 varied by erosion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention erodes a target by creating a magnetic field line shape along a target surface shape that changes due to erosion in a target area by a magnet arranged below the target or protruding from the target. The present invention relates to a magnetron sputtering method and an apparatus, which are capable of suppressing a variation in film forming conditions associated with the above and enabling stable film formation for a long time.

[0002]

2. Description of the Related Art In a magnetron sputtering apparatus, a magnetic field is used to improve the plasma density and the film formation speed is increased. However, due to its structure, the target is eroded nonuniformly. In order to prevent this, various measures have been made so far. (For example, JP-A-55-2
No. 8386, etc. )

However, even in these apparatuses, the film forming conditions change greatly with erosion, and therefore the film forming conditions (sputtering current, sputtering voltage, etc.) must be adjusted in order to stably obtain the same film quality. I won't. Further, the targets attached to the cathode are not necessarily in the same state, and particularly when a plurality of targets are used, there is a drawback that the adjustment is very complicated.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems that conventional magnetron sputtering apparatuses have.

[0005]

That is, according to the present invention, a magnetic field is formed on a target surface to improve plasma density,
A magnetron sputtering method for performing erosion of a target surface by sputtering, in which magnetic field lines in the above magnetic field are provided along the surface shape of the target that changes by erosion to perform sputtering, and a new magnetron sputtering method is provided. To do.

Further, the present invention is a magnetron sputtering apparatus capable of forming a magnetic field on the target surface to improve the plasma density and performing erosion on the target surface by sputtering. The present invention newly provides a magnetron sputtering device characterized in that it can be generated so as to follow the surface shape of a target that changes due to erosion.

In a usual magnetron sputtering apparatus, the magnets 4 are generally arranged as shown in FIG. 4 (a). Therefore, a magnetic field as shown in FIG. 4B is generated in the target area. (The state of the magnetic field is shown by the distribution of the lines of magnetic force 3.) In this case, the plasma has the highest density at the center of curvature of the lines of magnetic force 3, that is, at B⊥ = 0, and the density gradually increases as it goes around it. It gets thinner. Therefore, the target 1 is generally eroded as shown in FIG.

At this time, a conventional device, for example, Japanese Patent Laid-Open No.
In the device shown in 5-28386, the magnetic force lines 3 are devised so as to be parallel to the surface shape of the target 1, but the deviation between the magnetic force line shapes and the target surface shape due to erosion is mentioned. Absent.

In fact, when the target is used for a long time, electrons cannot be effectively confined on the target surface due to the deviation of the magnetic field line shape and the target surface shape due to the erosion, so that the plasma cannot be effectively trapped. The density value and distribution change, and the film forming conditions change. The reason for this is that, as shown in FIG. 5B (a view observed in a cross section in which drift due to an electric field is not visible), the electrons 6 move along the lines of magnetic force 3, and therefore the shape of the lines of magnetic force 3 and the target 1 This is because when the surface shape is different, the electrons move away from the target surface, and the electron density on the target surface decreases.

In the apparatus according to the present invention, as shown in FIG. 1, the magnetic force lines 3 have a wavy shape, and even if the surface of the target 2 changes due to erosion, the magnetic force lines 3 always have the shape of the target surface. It is designed to be as parallel as possible. Therefore, the fluctuation of the electron density (plasma density) in the target surface shape as described above is prevented. The shaded area in FIG. 1 indicates the erosion region 5 of the target. 2 is a backing plate.

[0011]

FIG. 2 shows the arrangement of the magnets 4 and the shape of the lines of magnetic force 3 in the embodiment of the present invention. The surface shape of the target that has never been used is flat. In response to this,
The magnetic lines of force are flattened like the target surface. As the erosion progresses, the target surface shape changes as shown in FIG. 3. In response to this, the magnetic force lines have a wavy shape, which follows the eroded target surface shape.

[0012]

According to the present invention, it is possible to suppress fluctuations in film forming conditions due to erosion of a target and perform stable sputtering for a long time.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing the distribution of magnetic force lines in an apparatus of the present invention.

FIG. 2 is a sectional view showing the arrangement of magnets and the distribution of lines of magnetic force in the device of the present invention.

FIG. 3 is a partial cross-sectional view showing an erosion shape of a target by the device of the present invention.

4A is a cross-sectional view of a conventional device, and FIG. 4B is a cross-sectional view showing a distribution of magnetic force lines of the conventional device.

5A is a sectional view showing an erosion region of a target by a conventional apparatus, and FIG. 5B is a sectional view showing a state after the target is eroded by a conventional apparatus.

[Explanation of symbols]

 1 Target 2 Backing Plate 3 Magnetic Field Line 4 Permanent Magnet 5 Erosion Region 6 Electron

Claims (8)

[Claims] 1. A magnetron sputtering method in which a magnetic field is formed on a target surface to improve plasma density, and erosion of the target surface is performed by sputtering, wherein magnetic force lines in the magnetic field follow a surface shape of the target which is changed by erosion. The magnetron sputtering method is characterized in that it is provided in such a manner as to perform sputtering. 2. The magnetron sputtering method according to claim 1, wherein changes in sputtering conditions caused by changes in the shape of the target surface due to erosion are suppressed. 3. The magnetron sputtering method according to claim 1, wherein the magnetic field is generated by a permanent magnet. 4. The magnetron sputtering method according to claim 3, wherein the magnetic field is generated by a combination of a plurality of permanent magnets. 5. A magnetron sputtering apparatus capable of forming a magnetic field on a target surface to improve plasma density and performing erosion on the target surface by sputtering, wherein magnetic lines of force in the magnetic field are changed by erosion. A magnetron sputtering device characterized in that it can be generated along the surface shape of a target. 6. The magnetron sputtering apparatus according to claim 5, wherein changes in sputtering conditions caused by changes in the shape of the target surface due to erosion are suppressed. 7. The magnetron sputtering apparatus according to claim 5, wherein the magnetic field is generated by a permanent magnet. 8. The magnetron sputtering apparatus according to claim 7, wherein the magnetic field is generated by a combination of a plurality of permanent magnets.