JPH09165673A - Thin film forming device and thin film forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel technique capable of forming thin films without contg. raw material particulates at the time of forming the thin films by a vacuum arc vapor deposition method. SOLUTION: 1. This device has a condenser as a main discharge power source which is constituted by arranging a cylindrical anode around a target as a cathode and arranging trigger electrodes near the cathode and executes a pulse electric discharge between the cathode spot generated by a trigger electric discharge and the anode. 2. The trigger electric discharge is generated by applying high-voltage pulses between the trigger electrodes and the target material by using the thin film forming device constituted by arranging the cylindrical anode around the target material as the cathode and arranging the trigger electrodes near the cathode. The electrons and ions generated by the main electric discharge between the cathode spot generated on the target material and the anode are thereafter accelerated and moved toward the substrate, by which the metallic thin films are formed on the substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thin film forming apparatus and a thin film forming method.

[0002]

2. Description of the Related Art Various physical and chemical vapor deposition methods are known as thin film forming methods.

For example, there is a vacuum arc vapor deposition method in which discharge current is concentrated in a region called a cathode spot while the thin film forming raw material is hardly melted by arc discharge in a vacuum. Conventionally, in the vacuum arc vapor deposition method, a disk-shaped target facing the substrate is used as a vapor deposition source,
The arc spot is moving on its surface. In thin film formation by such vacuum arc evaporation method, the material droplets generated at the cathode spot scatter and reach the substrate directly, so particles are formed and mixed into the thin film to form a flat film. It may not be done.

[0004]

SUMMARY OF THE INVENTION It is a principal object of the present invention to provide a new technique capable of forming a dense and smooth thin film containing no raw material fine particles when forming a thin film by a vacuum arc vapor deposition method.

[0005]

The present inventor has conducted research in view of the above-mentioned state of the art, and as a result, improved the structure of an arc discharge electrode in a vacuum arc vapor deposition apparatus to achieve the above object. It has been found that

That is, the present invention provides the following thin film forming apparatus and thin film forming method.

[0007] 1. A cylindrical anode was placed around the target material as the cathode, a trigger electrode was placed near the cathode, and a capacitor was provided as the main discharge power source for performing pulse discharge between the cathode spot generated by the trigger discharge and the anode. A thin film forming apparatus characterized by the above.

[0008] 2. Using a thin-film forming device in which a cylindrical anode is placed around the target material as the cathode and a trigger electrode is placed near the cathode, a high voltage pulse is applied between the trigger electrode and the target material to trigger. After discharging, a thin film characterized by forming a metal thin film on the substrate by accelerating and moving electrons and ions generated by the main discharge between the cathode spot and the anode generated on the target material toward the substrate. Forming method.

3. 3. The thin film forming method as described in 2 above, wherein the main discharge is pulse discharge using a capacitor as a power source.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the embodiments shown in the drawings.

As shown in FIG. 1, in the apparatus according to the present invention, a cylindrical anode is provided around the cathode (target material) of the vacuum arc discharge, and a high voltage is provided between the trigger electrode and the cathode arranged near the cathode. A voltage pulse is applied to trigger discharge. The point or region (cathode spot) where current is concentrated on the cathode due to this trigger discharge.
Then, a main discharge is started between the cathode spot and the anode to grow and move the cathode spot, and the atoms, ions and droplets generated in the cathode spot are emitted.

When the main discharge is continuously continued for a long time, the cathode is heated and finally melted, which causes a phenomenon similar to a normal melt vapor deposition method (melt vapor deposition method utilizing resistance conduction, electron beam, high frequency induction, etc.). As a result, a film containing particles is formed, and it is necessary to finish the main discharge before the cathode is melted. For this purpose, the charged capacitor is used as the main discharge power source. A pulsed power source is preferably used for good control of the operation.

In the present invention, in order to prevent melting of the cathode, the time of one arc discharge is limited.
Arc discharge is repeated as many times as necessary until a thin film having a desired film thickness is formed.

Also in the present invention, the raw material droplets are formed at the cathode spot, and they are deposited mainly on the anode, which can be linearly reached from the spot. On the other hand, the atoms and ions generated in the space between the anode and the cathode travel as a plasma flow in the direction in which the substrate is arranged and are deposited on the substrate to form a film. At this time, a magnetic field is generated concentrically around the anode electrode by the current flowing to the anode electrode. Since this magnetic field and the current flowing from the cathode to the anode are orthogonal to each other, an electromagnetic force acts on the current components, ions and electrons, which accelerate them toward the substrate and deposit them on the substrate to form a film. To do. On the other hand, the raw material droplets, which are much heavier than the atoms and ions, are hardly affected by the electromagnetic force, and thus are not accelerated toward the substrate and are not taken into the film. Therefore, the film formed on the substrate becomes smooth.

When forming a thin film of an insulating compound, a conductive substance is used as a target material, and oxygen, nitrogen or the like is supplied to the atmosphere, so that an insulating compound such as an oxide or a nitride is formed. Should be formed.

[0016]

【The invention's effect】

1. According to the present invention, since a flat film can be obtained, vapor deposition by the vacuum arc method can be widely used.

2. In the usual vapor deposition method, most of the targets are melted, but in the present invention, it is not necessary, so that a refractory metal film such as carbon or tungsten can be easily formed, and the energy used for heating can be reduced. It is possible to reduce the number and simplify the power supply device.

3. Unlike ordinary vapor deposition methods, since there is no radiant heat from the high temperature raw material melt, an inexpensive substrate with poor heat resistance can be used.

4. Since the raw material melt does not exist, the vapor deposition direction is not restricted by gravity, and the vacuum chamber can be freely attached. It can also be performed under zero gravity.

[5] Since there is no need for heating, it is possible to produce a high-purity film without the need for equipment for dealing with a decrease in the degree of vacuum during the vapor deposition operation due to degassing accompanying heating.

6. When the main discharge is performed by the short-time pulse, the instantaneous evaporation rate is extremely high, and therefore the deterioration of the purity due to the intake of the residual gas is small.

7. Since the arc discharge has a very high ionization rate, it is suitable for a substrate bias using ions, ion plating, plasma for an ion source, and the like.

8. The method of the present invention having many advantages as described above is useful for production of electronic materials such as semiconductors, formation of optical thin films, and surface modification for the purpose of anticorrosion and decoration.

[0024]

EXAMPLES Examples are shown below to further clarify the features of the present invention.

Example 1 In the apparatus shown in FIG. 1, vacuum arc discharge was performed under the following conditions to form an iron thin film (0.03 μm) on a polymer material (trademark “Kapton” manufactured by DuPont) film. .

* Trigger part: power supply 5 kV, resistance 50 MΩ,
Capacitor 0.33μF * Main discharge part: Power supply 90V, Capacitor 8800μF * Target: Iron, Diameter 8mm * Vacuum level: 10 ^-7 Torr The surface of the obtained iron thin film was observed by a secondary electron microscope (SEM) image, and it was dense. It was confirmed that a smooth thin film was obtained.

On the other hand, when the surface of the iron thin film obtained by the conventional vacuum arc discharge method was observed by the SEM image, it was confirmed that particles derived from the raw material droplets were present and the smoothness was poor.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of a thin film forming apparatus according to the present invention.

Front page continued (72) Inventor Jun Kinomura 1-831 Midorigaoka, Ikeda, Osaka Prefecture Industrial Technology Institute, Osaka Institute of Industrial Technology (72) Inventor Nobuteru Tsubouchi 1-831, Midorigaoka, Ikeda, Osaka Industry Institute of Industrial Science and Technology, Osaka Institute of Technology (72) Inventor Yoshiaki Ayano 1-38, Midorigaoka, Ikeda, Osaka Prefecture

Claims (3)

[Claims] 1. A main discharge power source for arranging a cylindrical anode around a target material as a cathode and a trigger electrode in the vicinity of the cathode to perform pulse discharge between a cathode spot generated by trigger discharge and the anode. A thin film forming apparatus comprising a capacitor as the above. 2. A thin film forming apparatus in which a cylindrical anode is arranged around a target material as a cathode and a trigger electrode is arranged near the cathode, and a high voltage is applied between the trigger electrode and the target material. Electrons and ions generated by the main discharge between the cathode spot and the anode generated on the target material are accelerated and moved toward the substrate after a pulsed trigger discharge to form a metal thin film on the substrate. And a method for forming a thin film. 3. The thin film forming method according to claim 2, wherein the main discharge is performed by pulse discharge using a capacitor as a power source.