JP2001262337A - Magnetron sputtering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetron sputtering system by which the thickness distribution of a thin film to be deposited on the substrate to be treated can be uniformized. SOLUTION: This system is provided with a target 2 arranged oppositely to the substrate 1 to be treated and a magnetic field forming means 3 arranged on the back side of the target 2 and forming the magnetic field for magnetron discharge in front of the target 2. The magnetic field forming means 3 has an annular large diameter magnet 3a with an elliptical external form and an annnular small diameter magnet 3b with an elliptical external form arranged in the inside of the large diameter magnet 3a. Magnetic flux for forming the magnetic field for magnetron discharge is formed from either the large diameter magnet 3a or the small diameter magnet 3b toward the other direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus for forming a magnetic field for magnetron discharge in front of a target.

[0002]

2. Description of the Related Art In a magnetron sputtering apparatus, a target is arranged to face a substrate to be processed, a magnetron discharge is generated in front of the target using a magnetic field, plasma is formed, and ions in the plasma are applied to the target. This is an apparatus for forming a film by causing the target particles to be emitted by sputtering to be emitted by sputtering and depositing the released target particles on the surface of the substrate to be processed.

[0003] In a conventional magnetron sputtering apparatus, a magnet for forming a magnetic field for magnetron discharge is used.
A race track type or a circular type is used.

[0004]

The distribution of the magnetic field lines formed by the above-mentioned race track type or circular magnets is based on the assumption that a plurality of points where the magnetic field lines are parallel to the target surface are imaginary parallel to the target surface. A virtual circle (or virtual ellipse) formed by connecting points located on a plane has a ratio of the major axis to the minor axis of 1 to 1.2.
Was in the range. In such a conventional magnet, since the position where the particles emitted from the target by sputtering are the most overlapped on the major axis and the minor axis of the ellipse, the distribution of the film thickness and the reflectance of the thin film formed on the substrate to be processed. Becomes non-uniform. When the distribution of the film thickness and the reflectance becomes non-uniform as described above, the yield of the product is deteriorated. Therefore, it is necessary to improve these distributions.

[0005] Further, when the magnet having the above configuration is used,
Since the erosion region of the target overlaps the major axis and the minor axis of the ellipse, there is a problem that the target is locally worn away, the life of the target is shortened, and the utilization efficiency is reduced.

The present invention has been made in view of the above circumstances, and has as its object to provide a magnetron sputtering apparatus capable of making the thickness distribution of a thin film formed on a substrate to be processed uniform. .

[0007]

In order to solve the above-mentioned problems, the present invention provides a target disposed to face a substrate to be processed and a magnetic field for magnetron discharge disposed on the back side of the target. Magnetic field forming means for forming in front of the magnet, the magnetic field forming means, an annular large-diameter magnet having an elliptical outer shape, and disposed inside the large-diameter magnet, the elliptical An annular small-diameter magnet having an outer shape, and lines of magnetic force for forming a magnetic field for magnetron discharge are formed from any one of the large-diameter magnet and the small-diameter magnet toward one of the other. It is characterized by being.

Preferably, a virtual ellipse formed by connecting points located on a virtual plane parallel to the surface of the target with respect to a plurality of points where the lines of magnetic force are parallel to the surface of the target is , The ratio of the major axis to the minor axis is about 1.9.

Preferably, the ratio of the major axis to the minor axis of the elliptical outer shape of the large diameter magnet is smaller than the ratio of the major axis to the minor axis of the elliptical outer shape of the small diameter magnet.

Preferably, the ratio of the major axis to the minor axis of the elliptical outer shape of the large diameter magnet is about 1.6, and the ratio of the major axis to the minor axis of the elliptical outer shape of the small diameter magnet is It is about 2.6.

Preferably, a center axis of the magnetic field forming means is eccentric with respect to a center axis of the target, and the magnetic field forming means rotates around the center axis of the target as a rotation center axis.

Preferably, the erosion region is swept over the entire surface of the target by moving the magnetic field forming means with respect to the target.

Preferably, the apparatus further comprises a center mask covering a central portion of the substrate to be processed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magnetron sputtering apparatus according to one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the magnetron sputtering apparatus according to the present embodiment includes a target 2 disposed to face a substrate 1 to be processed and a magnetic field for magnetron discharge disposed on the back side of the target 2. The apparatus includes a magnetic field forming means 3 for forming a magnetic field in front of the target 2 and a center mask 4 for covering a central portion of the substrate 1 to be processed.

As shown in FIGS. 1 and 2, the magnetic field forming means 3 has an annular large-diameter magnet 3a having an elliptical outer shape, and is arranged concentrically inside the large-diameter magnet 3a and has an elliptical shape. And an annular small-diameter magnet 3b having an outer shape. Magnetic lines of force for forming a magnetic field for magnetron discharge are formed from the N pole surface of the large diameter magnet 3a to the S pole surface of the small diameter magnet 3b. The polarities of the large-diameter magnet 3a and the small-diameter magnet 3b may be reversed.

The large-diameter magnet 3a and the small-diameter magnet 3b are
It is fixed to. As shown in FIG.
Are eccentric with respect to the rotation center axis of the rotating plate 5. The rotation center axis of the rotating plate 5 is aligned with the target 2
And the center axis of the substrate 1 to be processed. Therefore, the center axis of the magnetic field forming unit 3 is eccentric with respect to the center axis of the target 2, and the magnetic field forming unit 3 rotates around the center axis of the target 2 as the rotation center axis. Rotating plate 5
The erosion region is swept over the entire surface of the target 2 by the movement of the magnetic field forming means 3 with the rotation of.

The ratio of the major axis a2 to the minor axis a1 of the elliptical outer shape of the large diameter magnet 3a is about 1.6. The ratio of the major axis b2 to the minor axis b1 of the elliptical outer shape of the small-diameter magnet 3b is about 2.6.

As shown in FIGS. 1 and 3, a plurality of points P at which the lines of magnetic force formed by the large-diameter magnet 3a and the small-diameter magnet 3b are parallel to the surface of the target 2 are shown. A virtual ellipse formed by connecting points located on a virtual plane parallel to the short axis c1
Is about 1.9.

In this embodiment having the above configuration,
In the region closed by the magnetic circuit, it is possible to effectively improve the plasma density even when the gas pressure is low, and the magnetic field position where the direction of the magnetic field lines is parallel to the surface of the target 2 is higher than the other positions. Also, the target particles can be effectively released by sputtering. Then, a virtual ellipse formed by connecting a plurality of points P at which magnetic lines of force formed by the large-diameter magnet 3a and the small-diameter magnet 3b are parallel to the surface of the target 2 on a virtual plane parallel to the surface of the target 2 However, the large-diameter magnet 3a has a ratio of the major axis c2 to the minor axis c1 of about 1.9.
Since the small-diameter magnet 3b is formed and arranged, the thickness distribution of the thin film deposited on the surface of the substrate 1 to be processed becomes uniform.

Further, the central axis of the magnetic field forming means 3 composed of the large-diameter magnet 3a and the small-diameter magnet 3b is decentered with respect to the central axis of the target 2, and the central axis of the target 2 is set as the rotational central axis. Since the forming means 3 is rotated, it is possible to sweep the erosion area of the target 2 over the entire surface of the target 2,
Thus, the target 2 can be prevented from being locally worn, the life of the target can be extended, and the uniformity of the film thickness can be improved particularly in a film forming process using a center mask.

[0022]

As described above, according to the present invention, the magnetic field for magnetron discharge is formed in front of the target by the magnetic field forming means having the elliptical annular double magnet. The thickness distribution of the thin film formed by the emitted target particles being deposited on the surface of the substrate to be processed becomes uniform.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a magnetron sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a view taken along line AA of FIG. 1;

FIG. 3 is a view taken along the line BB of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate to be processed 2 Target 3 Magnetic field forming means 3a Large diameter magnet 3b Small diameter magnet 4 Center mask 5 Rotating plate

Claims (7)

[Claims] 1. A target disposed opposite to a substrate to be processed, and magnetic field forming means disposed on the back side of the target for forming a magnetic field for magnetron discharge in front of the target. In the magnetron sputtering apparatus, the magnetic field forming means includes an annular large-diameter magnet having an elliptical outer shape, and an annular small-diameter magnet having an elliptical outer shape, which is disposed inside the large-diameter magnet. A magnetron sputtering apparatus, wherein magnetic lines of force for forming a magnetic field for magnetron discharge are formed from one of the large-diameter magnet and the small-diameter magnet toward one of the other. 2. A virtual ellipse formed by connecting points located on an imaginary plane parallel to the surface of the target with respect to a plurality of points where the lines of magnetic force are parallel to the surface of the target has a short length. The ratio of the long axis to the long axis is about 1.
9. The magnetron sputtering apparatus according to claim 1, wherein 3. The ratio of the major axis to the minor axis of the elliptical outer shape of the small diameter magnet is smaller than the ratio of the major axis to the minor axis of the elliptical outer shape of the large diameter magnet. 3. The magnetron sputtering apparatus according to 1 or 2. 4. The ratio of the major axis to the minor axis of the elliptical outer shape of the large diameter magnet is about 1.6, and the ratio of the major axis to the minor axis of the elliptical outer shape of the small diameter magnet is about 2. 6. The magnetron sputtering apparatus according to claim 3, wherein the number is 6. 5. The magnetic field forming means according to claim 1, wherein a center axis of said magnetic field forming means is eccentric with respect to a center axis of said target, and said magnetic field forming means rotates around a center axis of said target as a rotation center axis. The magnetron sputtering apparatus according to claim 1. 6. The magnetron sputtering apparatus according to claim 1, wherein the erosion region is swept over the entire surface of the target by moving the magnetic field forming means with respect to the target. apparatus. 7. The apparatus according to claim 1, further comprising a center mask covering a central portion of said substrate to be processed.
The magnetron sputtering apparatus according to any one of the above.