JPS63125675A - Magnetron sputtering device - Google Patents

Abstract

PURPOSE:To uniformize the erosion of a target by ion bombardment and to improve the utilization efficiency thereof by providing a mechanism for moving a magnet group arranged alternately with N poles and S poles continuously in one direction where the magnets are arranged to a cathode part. CONSTITUTION:A yoke 3 provided alternately with plural pieces of permanent magnets 21 having the N poles at the top ends and the S poles at the bottom end and the permanent magnets 22 having the S poles at the top end and the N poles at the bottom end is provided to the cathode part of a magnetron puttering device. Magnetic lines of force are generated in a direction B if the surface of the target 1 on the side opposite from the permanent magnets 21, 22 is installed in a low pressure gaseous atmosphere of about 1X10<-3>-1X10<-2>Torr. Magnetron discharge is generated by the effect of an electromagnetic field when a negative voltage is impressed from a power supply 9 to a cathode 8. The magnetron discharge shift from the left to the right if the yoke 3 and the permanent magnets 21, 22 are moved in a direction C by a rotating wheel 4. The part eroded by the ion bombardment is thereby moved on the target 1 as well, by which the erosion of the target is uniformized and the utilizing efficiency of the target 1 is improved; in addition, the thickness of the formed thin film is uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetron sputtering apparatus that forms a film by utilizing a cathode sputtering phenomenon caused by discharge in a magnetic field.

BACKGROUND ART Sputtering is a phenomenon in which gas ions generated by glow discharge are accelerated by an electric field and collide with a cathode, whereby the cathode material is ejected as atoms or a group thereof.

The sputtering device is a device that attaches and deposits the cathode material emitted from the cathode onto a substrate facing the cathode, and forms a film of the cathode material on the substrate 2.

In recent years, magnetron sputtering equipment with orthogonal electromagnetic field configuration has become the mainstream sputtering equipment, which has a faster film formation rate (for example, "Thin Film Technology" by Shigeru Hayayo and Kiyotaka Wasa).
(See Chapter 5, 5.2 Sputtering device).

In a magnetron sputtering device that uses orthogonal electromagnetic field discharge, the magnetic field distribution near the target surface becomes non-uniform. As a result, the target surface is subjected to non-uniform ion bombardment, resulting in localized erosion of the target surface. For this reason, the life of the target was limited to the point at which local erosion progressed and the erosion reached the bonding surface between the target and the target back plate, and the utilization efficiency of the target was extremely low.

Hereinafter, a conventional magnetron sputtering apparatus as described above will be explained with reference to the drawings.

FIG. 3 shows a cathode section of a conventional magnetron sputtering apparatus. In Figure 3, 1 is the target, 21
2L and 21b are permanent magnets with an N pole on the upper end and a 3-page S pole on the lower end, 23 is a permanent magnet with an S pole on the upper end and an N pole on the lower end, 3 is a coke for forming a magnetic circuit, and 5 is on the target 1. A ground potential shield plate for limiting the discharge area of It is.

The operation of the cathode section of the magnetron sputtering apparatus configured as described above will be described below.

The back side of the surface of target 1 relative to the permanent magnets 211L, 21t) and 23 is 1X10To□1X10 Torr
installed in a low-pressure gas atmosphere. On this surface of the target 1, the permanent magnets 211L, 21b, 23 [, since magnetic lines of force are generated in the direction indicated by the arrows, the cathode 8
When a negative voltage gold is applied by the power source 9, a magnetron discharge is generated on the target 1 due to the action of an electromagnetic field. This magnetron discharge is confined by the convergent magnetic field lines A, and as a result, the target in this area is subjected to strong ion bombardment and severe erosion.

In forming a thin film using a magnetron sputtering device, a substrate is provided opposite the eroded surface of the target 1, and a thin film containing the target material as a main component is deposited on the substrate. FIG. 4 shows a cross section of the target 1 after it has been exposed to magnetron discharge for a long time and sputtered, and the thickness distribution of the thin film deposited on the substrate. In FIG. 4, reference numeral 10 represents a cross-sectional shape of the target 1 cut in the direction in which the permanent magnets 21a, 21b, and 23 are arranged, and a curve X above the cross-sectional shape represents the film thickness distribution of the deposited film on the substrate immediately above the cross-section.

Problems to be Solved by the Invention However, as shown in Figure 4, the target surface corresponding to the magnetic field convergence area is deeply eroded, but the target surface away from the magnetic field convergence area is hardly eroded; Therefore, the life of the target is determined by the depth of erosion in the magnetic field convergence area, and there is a problem in that only about 10 to 20% of the total target volume is utilized.

Page 5 Also, in recent years, expensive target materials, mainly rare metals, have begun to be used in thin film formation, and there has been a growing demand for improved target utilization efficiency, making this issue extremely important.

In view of the above-mentioned problems, the present invention provides a magnetron sputtering apparatus that can improve target utilization efficiency.

Means for Solving the Problems In order to achieve this object, the magnetron sputtering apparatus of the present invention generates a magnetic field in which a group of magnets in which N-pole magnets and S-pole magnets are arranged alternately moves continuously in the arrangement direction. The structure is such that the mechanism is provided in the cathode section.

Effect: With this configuration, the magnetic field convergence part of the target 2 sweeps the target uniformly, the target surface is uniformly eroded, there is no local erosion of the target, and the efficiency of target utilization is greatly improved. Become.

Embodiment 6 Below, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cathode section of a magnetron sputtering apparatus in one embodiment of the present invention. In Figure 1, 1
is a target, 21 is a permanent magnet with an N pole at the top end and an S pole at the bottom end, 22 is a permanent magnet with an S pole at the top end and a N pole at the bottom end, and 3 is a yoke that functions as a belt, as shown in Figure 1. A plurality of permanent magnets 21 and 22 are provided alternately on the belt s. 4 is a rotating wheel for driving the yoke 3 and permanent magnets 21 and 22, 5 is a shield plate, and 6 is a base plate.
1-17 is an insulated port, 8 is a cathode, 9 is a beam, C or R, F power source.

The operation of the cathode section of the magnetron sputtering apparatus configured as described above will be described below.

The surface of the target 1 opposite to the surface facing the permanent magnets 21 and 22 is placed in a low pressure gas atmosphere of 1.times.10 Torr to 1.times.10 Torr. On this surface of the target 1, magnetic lines of force are generated by the permanent magnets 21, 22 in the direction indicated by arrow B by 7 heges.

When a negative voltage is applied to the cathode 8 by a power source 9, a magnetron discharge occurs on the target 1 due to the action of the electromagnetic field. At this time, when the rotary wheel 4 is driven to move the yoke 3 and the permanent magnets 21 and 22 in the direction of arrow C, the magnetron discharge confined by the converging magnetic field lines B moves over the target 1 from left to right in FIG. move towards. Along with this, the eroded portion due to ion bombardment also moves on the target 1.

In order to prevent corrosion caused by ion bombardment from reaching the cathode 8, the area of magnetron discharge is limited by the shield plate 5.

Figure 2 shows the cross section of the target 1 and the film thickness distribution of the thin film deposited on the substrate after sputtering by exposing the target 1 to magnetron discharge for a long time using the cathode section of the magnetron sputtering apparatus according to this embodiment. . In FIG. 2, reference numeral 11 indicates the cross-sectional shape of the target 1 cut in the direction in which the permanent magnets 21 and 22 are arranged, and the curve Y above it indicates the film thickness distribution of the deposited film on the substrate directly above the cross-section of the target 1.
Target 1 is uniformly eroded.

As described above, according to this embodiment, by continuously moving the permanent magnets 21 and 22, the eroded portion of the target due to ion bombardment is swept over the entire surface of the target, and as shown in FIG. Erosion can be realized and target utilization efficiency can be improved to 60-60%. Furthermore, it is possible to achieve uniform film deposition speed on the substrate and to produce a thin film with a uniform thickness distribution.

Furthermore, in this example, the ion bombardment area on the target is expanded by arranging the permanent magnets densely, so that the target is eroded at a high rate and a thin film can be formed at high speed.

Note that in this example, the shape of the target was square, but
By changing the shape of the target plate 5, even a round target can be used.

Effects of the Invention The present invention uses a group of magnets in which N poles and S poles are arranged alternately to generate a magnetic field that moves continuously in one direction in the arrangement direction.By providing a main mechanism in the cathode part, ion bombardment can be achieved. This makes it possible to uniformly erode the target, improve target usage efficiency, and make the thickness of the thin film uniform.Furthermore, by densely arranging the permanent magnets, it is possible to achieve the effect of high-speed deposition of thin films. This makes it possible to realize an excellent magnetron sputtering device that can perform

[Brief Description of the Drawings] Fig. 1 is a cross-sectional perspective view of a magnetron sputtering apparatus in an embodiment of the present invention, Fig. 2 is a corresponding diagram showing a target cross section and film thickness distribution after long-time sputtering, and Fig. 3 4 is a cross-sectional perspective view of a conventional magnetron sputtering apparatus, and FIG. 4 is a corresponding diagram showing a target cross section and film thickness distribution after long-time sputtering. 1...Target, 3...Yoke, 4
... Rotating wheel, 5 ... Shield plate, 6 ...
・・・Base plate, finished...Insulated boat, 8
...Cathode, 9...-Power supply, 10.11
...Target cross section, 21.22...
permanent magnet. Name of agent: Patent attorney Toshio Nakao and 1 other person
3 8-Ili! 1 big groan

Claims (1)

[Claims] A magnetron sputtering apparatus characterized in that a magnetic field generating mechanism is provided in a cathode portion, in which a group of magnets in which N poles and S poles are alternately arranged move continuously in one direction of arrangement.