JPS6260867A - Magnetron sputtering apparatus - Google Patents

Abstract

PURPOSE:To obtain a thin film free from defects such as a projection of foreign matter and pinholes by cleaning the surface of a target before film formation. CONSTITUTION:In this magnetron sputtering apparatus, a yoke is composed of a cylindrical yoke 23A placed on the rear sides of the 1st and the 2nd permanent magnets 21, 22 and a cruciform yoke 23B bonded crosswise to the yoke 23A and supporting the 2nd magnet 22. The yoke 23B is wrapped with a coil 24 and a power source 25 for excitation is connected to the coil 24. Before a film is formed, the coil 24 is optionally excited and the intensity of a magnetic filed applied to the surface of a target 9 is varied to clean the surface of the target 9.

Description

[Detailed Description of the Invention] [Summary] α-F is deposited on a substrate using the reactive magnetron spacing method.
This is an apparatus for forming an e203 compound film, which prevents deposits made of target oxides etc. attached to parts of the target that are not sputtered from re-depositing on the substrate, and this deposit A magnetron sputtering device that eliminates film defects caused by adhesion.

[Industrial application field]

The present invention relates to improvements in magnetron sputtering equipment used in the manufacture of various magnetic recording media and semicircular magnetronic circuit elements. The present invention relates to a structure of a target support that prevents deposits attached to the non-spinning portions of the substrate from re-attaching onto the substrate and causing film defects.

For example, on a non-magnetic substrate such as an aluminum substrate, α-F
An e20a film is formed using a reactive magnetron bathtub method or the like, and this is heat-treated in an oxidizing and reducing gas atmosphere to convert it into a magnetic film of 7-Fe203 film, thereby forming a magnetic disk.

When such magnetic recording media are manufactured using the reactive magnetron sputtering method, unnecessary deposits such as target and node oxides are prevented from adhering to the substrate, and bit errors due to the adhesion of these deposits are prevented. There is a need for a magnetron sputtering device that prevents this phenomenon.

[Conventional technology]

Figure 3 is an explanatory diagram of a conventional magnetron sputtering device.
As shown in the figure, a non-magnetic substrate 3 is placed on a substrate installation stand 2 in an airtight container 1, and a target support 5 is placed at a position facing this substrate 3 with a shutter 4 interposed therebetween.

A plan view of this target support 5 is shown in FIG. Third
As shown in the figure and FIG. 4, a rectangular parallelepiped-shaped yoke 6 is installed inside the target support 5, and a frame-shaped yoke 6 along the inner circumference of the support 5 is provided on the yoke. a first permanent magnet 7 whose surface is an S pole and whose yoke 6 side is an N pole;
A rectangular parallelepiped-shaped second permanent magnet 8 is located in the center of the permanent magnet 7 and has a polarity opposite to that of the permanent magnet 7, and is provided in a double structure. And this double structure permanent magnet 7.8
An iron plate-shaped target 9 for forming a magnetic recording medium is supported by the support 5 above.

Further, the bottom of the target support 5 is provided with a target support 5.
A water cooling pipe 10 is provided for cooling the inside.

Here, the inside of the container 1 of the apparatus shown in FIG.
After evacuation using the exhaust pump 12 with the exhaust valve 11 open until the degree of vacuum reaches rr, for example, argon (Ar) and oxygen (02) are added in the volume ratio (
1: Introduce the sputtering gas of 1).

Then, while rotating the substrate 3 using the motor 13, a high voltage is applied using the power source 14 between the substrate mounting table 2 and the target support 5, and the valve 15 is opened to open the gas introduction pipe 16.
The introduced sputtering gas is turned into a plasma state,
These plasma-like ions collide with the target 9, and the oxide of the collided target 9 is deposited on the substrate 3.

Here, the first and second permanent magnets 7 and 8 installed in the target support 5 generate a magnetic field perpendicular to the electric field applied between the substrate mounting table 2 and the target 5, and this magnetic field causes plasma to be generated. The structure is such that electrons therein move in a cycloid on the target 5 to form a high-density plasma, and a plasma state can be easily realized even when the voltage applied between the substrate 3 and the target 5 is low. There is.

Such a sputtering device is usually called a magnetron sputtering device, and has a faster film formation rate than a bipolar sputtering device, etc., and since the plasma is focused in the vicinity (surface) of the target 5, It has the advantage of preventing temperature rise, can form thin films with low salt content, and has recently been used in manufacturing methods for magnetic recording media and the like.

[Problem that the invention seeks to solve]

However, in such a device, as shown in FIG. The electrons e are cycloidally transported along the direction of the magnetic field lines generated in the six directions of the arrows on the target 9.
Move while doing J.

Therefore, the region of the target 9 with a high plasma density to which the electrons e have moved is sputtered and eroded into a ring shape, but the central region 98 and the peripheral region 9B of the target 9 with a low plasma density to which the electrons have not been transferred. is hardly eroded.

Most of the components of the sputtered target 9 adhere to the substrate 3, but some of them collide with ions in the plasma, and these collided particles reattach to the uneroded parts 9A and 9B of the target 9. and deposit.

This deposit is usually an oxide of the target component, and since it is a high-resistance material, it gradually becomes electrically charged, and furthermore, it causes abnormal discharge and the like and scatters, and a part of it adheres to the substrate.

As shown in FIG. 6, such deposited particles are generally coarser particles 17 than normally sputtered particles and are formed in a sputtered film 18 for forming a magnetic recording medium.
These coarse particles 17 become large and have weak adhesion to the substrate 3, and are easily peeled off during the subsequent manufacturing process of the magnetic recording medium, causing defects in the magnetic recording medium at the peeled off portions.

If a magnetic disk is formed using such a magnetic recording medium, there will be problems such as bit errors occurring during recording and reproduction.

Therefore, a sputtering apparatus is desired in which deposits such as oxides of Kuget components on the target 5 do not adhere to the substrate 3.

[Means for solving problems]

A detailed explanatory view of the present invention aimed at solving the above problems is shown in FIG. 1, and a perspective view of the main part of the target support of the apparatus of the invention is shown in FIG.

As shown in FIGS. 1 and 2, in the sputtering apparatus of the present invention, a yoke 23 for a double-structured first permanent magnet 21 and a second permanent magnet 22 is connected to a frame-shaped yoke 23A and a frame-shaped yoke 23A. It consists of a cross-shaped yoke 23B coupled to a cross-shaped yoke 238.

Further, a coil 24 is wound around the cross-shaped yoke 23B, and a power source 25 for excitation is connected to the coil 24.

[Effect]

The sputtering apparatus of the present invention includes a second permanent magnet 22 disposed at the center inside the target support 5 and a target 5.
A part of the yoke 23Ba of the yoke 23 that magnetically couples the first permanent magnet 21 disposed around the yoke 23,
23Bb, 23Bc, and 23Bd are provided with coils 24, and by energizing or de-energizing the coils 24, a magnetic field change is applied to the magnetic circuit composed of the target 9, the permanent magnets 21, 22, and the yoke 23, and the substrate At the stage of press sputtering, in which the components of the target 9 are not deposited on the surface of the target 9, the components of the target 9 are cleaned and deposited on the surface of the target 9 without focusing the sputtering gas without leaking the magnetic field to the surface of the target 9. and removes deposits that cause defects in film formation.

Further, when sputtering the components of the target 9 onto the substrate 3 and depositing the sputtered film, the sputtering gas is focused and sputtered while a magnetic field is applied to the surface of the target.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram of a magnetron sputtering apparatus of the present invention, and FIG. 2 is an explanatory diagram of a main part of a target support in the apparatus of the present invention.

As shown in FIGS. 1 and 2, the sputtering apparatus of the present invention includes a rod-shaped yoke 23A along the inner peripheral surface of the target support 5, and a frame-shaped yoke 238 formed integrally with the rod-shaped yoke 23A. , and a cross-shaped yoke 23B extending toward the center to form a cross. A frame-shaped first permanent magnet 21 is provided on this frame-shaped yoke 23A, and a rectangular parallelepiped shape having magnetic poles in the opposite direction to the first permanent magnet 21 is provided at the center of the cross-shaped yoke 23B. A second permanent magnet 22 is provided. Among the cross-shaped yokes 23B extending from the lower part of the second permanent magnet 22 to the frame-like yoke 238, the yoke 23B
A coil 24 is provided in each of a, 23Bb, 23Bc, and 23Bd.

Also, a coil excitation mold for exciting this coil 24.
When tA25 is provided and the coil 24 is excited, the permanent magnet 2L
The winding direction of the coil is determined so that the magnetic field between 22 is strengthened. When the coil 24 is energized, the magnetic field leaks onto the target 9, and when the coil 24 is not energized, the magnetic field between the permanent magnets 2122 is set so that the magnetic field between the permanent magnets 2122 does not leak onto the surface of the target 9. Adjust the brightness.

A case will be described in which a magnetic film is sputtered onto the substrate 3 using such an apparatus.

A non-magnetic aluminum substrate 3 is placed on the substrate installation stand 2 of the airtight container 10 shown in FIG. On the other hand, a shutter 4 facing this substrate 3 covers a target support 5 having an iron target 9.

In this state, the inside of the container 1 is evacuated using the exhaust pump 12 connected to the exhaust valve 21 until a vacuum level of 10''6 torr is reached.

Next, the valve 15 is opened, and A is introduced from the gas introduction pipe 16.
A sputtering gas containing r gas and 02 gas in a volume ratio of (1:1) is introduced. In this state, the board installation stand 2 on which the board 3 is installed is rotated by the motor 3, the target 9 is covered with the shutter 4, and the power source 14 is connected between the board 3 and the target 9.
Apply a predetermined voltage using

At this point, the coil excitation N source 25 is turned off, and when the coil excitation power supply 25 is turned off,
The magnetic field generated by the permanent magnets 21, 22 does not leak onto the surface of the target 9.

In this way, the plasma-like sputtering gas ions are not focused and impinge on the entire surface of the target 9, and the deposits of film defects accumulated by TIF on the non-eroded area of the target 9 in the previous film forming process are removed. , are scattered and adhered to the shutter 4, and the surface of the target 9 is cleaned by ln.

In still another embodiment, the coil 24 is energized to
The winding direction of the coil 24 is set so that the magnetic field of the permanent magnets 21 and 22 weakens when the permanent magnets 21 and 22 are excited. Even when the coil 24 is not excited, the magnetic field between the permanent magnets 2L22 leaks from the surface of the target 9.

When cleaning the surface of the target 9 in this way, the coil 24 is energized to weaken the strength of the magnetic field applied to the surface of the target 9, and when the components of the target 9 are deposited on the substrate 3, the coil 24 is energized. is stopped and the strength of the magnetic field applied to the surface of the target 90 is increased.
The components of the target 9 are sputtered onto the substrate 3 by focusing the plasma.

In this way, deposits on the target that cause film defects in the film forming process are removed in advance, thereby reducing the time required to clean the surface of the target 9 and reducing the time required to form a sputtered film on the substrate. When using a sputtering method that takes a long time, there is an effect that leads to power saving.

〔Effect of the invention〕

As described above, according to the magnetron sputtering apparatus of the present invention, it is possible to purify the surface of the target with a simple operation prior to film formation, so that deposits such as target oxides from the target can be removed from the thin film to be formed. This has the effect that there is no scattering of coarse particles, and a thin film without defects such as foreign matter protrusions or pinholes can be obtained.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the magnetron sputtering apparatus of the present invention, Fig. 2 is a perspective view showing the main part of the target support of the apparatus of the present invention, Fig. 3 is an explanatory diagram of the conventional magnetron sputtering apparatus, and Fig. 4 5 is a plan view of a target support of a conventional apparatus, and FIG. 5 is a perspective view showing the surface condition of a conventional target. FIG. 6 is an explanatory diagram showing an inconvenient state of a sputtered film formed using a conventional apparatus. In the figure, ① is an airtight container, 2 is a substrate installation stand, 3 is a substrate, 4 is a shaft, 5 is a target support, 7.8 is a permanent magnet, 9 is a target throat, 10 is a water cooling tube, 11 is Exhaust valve, I2 is V pump, I3 is motor, 14 is power supply, 15 is valve, 16 is gas introduction pipe, 21.22 is permanent magnet, 23,
23A, 23B, 23Ba, 23Bb, 23B
23Bd is a yoke, 24 is a coil, and 25 is a coil excitation power source. Hidokoro 11n Mystery map-a 1 Illustration and shame 7-'f:'y Toto light hand 4 eyes 7 Shaosho Figure 2 @ 3 Figure

Claims (1)

[Claims] A target support (5) supporting a target (9) and a substrate (3) in a vacuum container (1) filled with sputtering gas.
), and a yoke (2) is placed inside the target support (5).
3), a double-structured first and second permanent magnet (21, 22) is provided on the yoke, and a voltage is applied between the substrate (3) and the target support (5), and the target In the apparatus for attaching components of the target (9) onto the substrate (3) using a magnetic field generated on the surface of the yoke (23), the first magnet (21, 22
); and a cross-shaped yoke (23B) that is coupled to the frame-shaped yoke (23A) in a cross-shaped manner and supports the second magnet (22). The cross-shaped yoke (23B) has a coil (
A power source (25) for excitation is connected to the coil (24), and by energizing or de-energizing the coil (24), the target (9) is A magnetron sputtering device characterized in that the intensity of a magnetic field applied to a surface is variable.