JPH0734242A - Sputtering device - Google Patents

Abstract

PURPOSE:To improve the uniformity of film quality and the film forming rate and to reduce particles by suppressing the accumulation of insulated films which are metal oxides on the parts other than erosion in a metallic target, preventing abnormal discharge and stabilizing plasma. CONSTITUTION:The sputtering device is constituted of a d.c. power source 11 applying voltage to a cathode 1 and generating plasma between a substrate 7, a high frequency power source 14 and a low-pass filter preventing the interference of high frequency with the d.c. power source 11, and insulated films which are metal oxides accumulating on the parts other than erosion on the surface of a metallic target 5 are applied with high frequency voltage simultaneously together with d.c. voltage, by which charge-up is prevented and discharge is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for an insulating film by reactive sputtering using a metal target.

[0002]

2. Description of the Related Art In recent years, sputtering devices have been used for magneto-optical disks, optical disks, recording films for video heads, insulating films,
It is often used for forming protective films.

An example of a conventional sputtering apparatus will be described below with reference to FIG. 2 in FIG.
Reference numeral 1 is a cathode on which a magnet pair 23 concentric with the yoke 22 is fixed, 24 is a backing plate for fixing a metal target 25, and 26 is a cooling water pipe for cooling the magnet pair 23 and the metal target 25. Reference numeral 27 is a substrate which is arranged so as to face the metal target 25 and on which a film is deposited by sputtering. Reference numeral 29 is a vacuum exhaust pump for creating a reduced pressure atmosphere in the vacuum chamber 28, and reference numeral 30 is a gas supply system for supplying a sputtering gas and a reactive gas into the vacuum chamber 28. Reference numeral 31 is a DC power supply for applying a voltage to the cathode 21 to generate plasma on the surface of the metal target 25.

The operation of the sputtering apparatus constructed as above will be described below. First, the inside of the vacuum chamber 28 is set to 1 by the vacuum exhaust pump 29.
Evacuate to a vacuum level of 0 ^-6 Torr. After that, argon gas and oxygen gas are introduced into the vacuum chamber 28 by the gas supply system 30, a vacuum degree of about 5 × 10 ⁻³ Torr is set, and a DC voltage is applied to the cathode 21 by the DC power supply 31. A plasma is generated inside the vacuum chamber 28. As a result, argon ions and oxygen radicals are generated. Further, the magnetic field 32 of the magnet pair 23 generates a portion 33 having a high plasma density, and the amount of collision of argon ions with the metal target 25 increases. Then, the particles are mainly scattered from the area, that is, the yellow john, and react with oxygen radicals to react with the substrate 2 and the substrate 2 is disposed oppositely.
A metal oxide is deposited on the surface of 7 to form an insulating film.

[0005]

However, in the above-mentioned structure, the concentric magnet pair 23 forms a ring-shaped portion having a high magnetic field strength, and the portion of the surface of the metal target 25 having a high magnetic field strength, that is, the plasma density is high. The collision amount of argon ions in the high portion is large, and the scattering of particles is large in the annular erosion region. Therefore, as shown in FIG. 4, particles that have reacted with oxygen radicals are deposited on the portion other than the erosion region as an insulating film 32 that is a metal oxide. At this time, since the metal oxide deposited on the portion other than the erosion region is an insulator, the voltage applied by the DC power supply 31 is charged up and abnormal discharge occurs, which makes the plasma unstable. In addition, the plasma will stop. As a result, there are problems that the film quality is not uniform and particles increase.

Further, the metal oxide is a metal target 25.
Due to the low sputtering rate, there is a problem that the film forming rate is reduced.

In view of the above-mentioned conventional problems, the present invention suppresses the deposition of an insulating film which is a metal oxide other than erosion, prevents abnormal discharge, and stabilizes the plasma, thereby improving the uniformity of film quality and the property film. An object of the present invention is to provide a sputtering apparatus that can improve the speed and reduce the particles.

[0008]

A sputtering apparatus according to the present invention comprises a vacuum chamber capable of maintaining a vacuum state, a vacuum pump for creating a reduced pressure atmosphere in the vacuum chamber,
The vacuum chamber was equipped with a gas supply system for supplying while adjusting the flow rate of the sputtering gas, a cathode on which a magnet body was arranged and a target was fixed, and a substrate which was arranged opposite to the cathode and formed by sputtering. The sputtering apparatus is characterized by including a direct current power source for applying a voltage to the cathode to generate plasma between the substrate, a high frequency power source, and a low pass filter for preventing high frequency waves from interfering with the direct current power source.

[0009]

According to the present invention, with the above-described structure, the insulating film which is a metal oxide deposited on the portion other than the erosion is applied to the DC voltage and the high frequency voltage is simultaneously applied to prevent the charge-up and stabilize the plasma. You can Therefore, deposition of the insulating film can be suppressed, abnormal discharge can be prevented, and plasma can be stabilized, so that uniformity of film quality can be improved and particles can be reduced.

Further, since the deposition of metal oxide having a low sputtering rate is suppressed, it is possible to prevent the film formation rate from decreasing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sputtering apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, 1 is a cathode and 2 is a yoke. 3 is a concentric magnet pair, 4 is a packing plate for fixing the target 5, 6 is a magnet pair 3, and a substrate on which a film is deposited by metal target sputtering. 9
Is a vacuum exhaust pump for creating a reduced pressure atmosphere in the vacuum chamber 8, and 10 is a gas supply system for supplying a sputtering gas into the vacuum chamber 8. Reference numeral 11 is a DC power supply for applying a DC voltage to the cathode 1 to generate plasma on the surface of the metal target 5, and 14 is a DC power supply 1
Simultaneously with 1, a high-frequency voltage is applied to the cathode 1 to generate plasma on the surface of the metal target 5, and 15 is a low-pass filter that does not prevent the high-frequency from interfering with the DC power supply. 2 shows the low-pass filter 15
2 is a circuit diagram of FIG.

The operation of the sputtering apparatus configured as described above will be described below. First, the inside of the vacuum chamber 8 is set to 10 ⁻⁶ by the vacuum exhaust pump 9.
Evacuate to the vacuum level of the Torr table. After that, argon gas and oxygen gas are introduced into the vacuum chamber 8 through the gas supply system 10, and the degree of vacuum is set to about 5 × 10 ⁻³ Torr. Here, the metal target 5 is cooled by the cooling water from the cooling water pipe 6. Next, to the cathode 1, a DC voltage and a high frequency power source 14 are supplied from the DC power source 11.
A high frequency voltage is applied to generate plasma inside the vacuum chamber 8. This plasma generates argon ions and oxygen radicals. Further, the magnetic field 12 of the magnet pair 3 generates a high plasma density portion 13,
The amount of collision of argon ions with the metal target 5 increases. Then, particles mainly scatter from the region, that is, erosion, react with oxygen radicals, and metal oxides are deposited on the surface of the substrate 7 arranged so as to oppose to form an insulating film.
At this time, the insulating film, which is a metal oxide, deposited on a portion of the surface of the metal target 5 other than the erosion is simultaneously applied with a high frequency voltage in addition to the DC voltage, so that charge-up is prevented and discharge is stabilized. Further, in the DC power supply 11, high frequency interference is prevented by the low pass filter 15,
Be protected.

As described above, according to this embodiment, by simultaneously applying the high-frequency voltage in addition to the direct-current voltage to the cathode 1, it is possible to prevent the charge-up of the insulating film, which is the metal oxide deposited on the portion other than the erosion, and to discharge. Can be made. That is, it is possible to control the deposition of the insulating film, prevent abnormal discharge, and stabilize the plasma.

Therefore, it is possible to improve the uniformity of film quality and reduce particles. Further, since the deposition of the metal oxide having a low sputtering rate is suppressed, it is possible to prevent the film formation rate from decreasing.

[0016]

As described above, according to the present invention, the high frequency power source for applying the high frequency voltage to the cathode simultaneously with the direct current voltage to generate the plasma on the surface of the metal target and the high frequency power source for the high frequency power source interfere with the direct current power source. Since the low pass filter for preventing is configured, it is possible to prevent charge-up and discharge by simultaneously applying a high frequency voltage to the insulating film which is a metal oxide deposited on a portion other than the erosion, in addition to the DC voltage. Therefore, the deposition of the insulating film can be controlled, abnormal discharge can be prevented, and plasma can be stabilized, so that film quality uniformity can be improved and particles can be reduced. Further, since the deposition of the metal oxide having a low sputtering rate is suppressed, it is possible to prevent the decrease in the film formation rate.

[Brief description of drawings]

FIG. 1 is a sectional view of a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a low-pass filter of the sputtering device in the example.

FIG. 3 is a sectional view of a conventional sputtering device.

FIG. 4 is a sectional view showing an insulating film deposition state of a metal target in a conventional example.

[Explanation of symbols]

 1 Cathode 2 Yoke 3 Magnet Pair 4 Backing Plate 5 Metal Target 7 Substrate 8 Vacuum Chamber 9 Gas Supply System 11 DC Power Supply 14 High Frequency Power Supply 15 Low Pass Filter

Claims (1)

[Claims] 1. A vacuum chamber capable of maintaining a vacuum state, a vacuum pump for reducing the pressure in the vacuum chamber, a gas supply system for supplying a sputtering gas into the vacuum chamber while adjusting a flow rate of a sputtering gas, and a magnet pair. A DC power supply for applying a voltage to the cathode and generating plasma between the cathode and the cathode, the cathode being arranged and having the target fixed, and the substrate arranged opposite to the cathode and formed by sputtering. When,
A sputtering apparatus comprising a high-frequency power source and a low-pass filter for preventing high-frequency interference with a DC power source.