JPS63166967A - Film forming device - Google Patents

Abstract

PURPOSE:To form thin films of uniform target materials on substrate surfaces by alternately disposing anodes and target cathods around the substrates in a gaseous Ar atmosphere and ionizing the gaseous Ar by the electric discharge of an AC voltage, thereby bombarding the targets. CONSTITUTION:The many cylindrical substrates 10 are mounted in a reaction vessel 1 and the many plasma generating electrodes 2, 3 are alternately disposed around the same. The electrodes 2 are the electrodes formed by thermally spraying films of stabilized zirconia onto the surfaces and the electrodes 3 are the counter electrodes having the polarity opposite from the polarity of the electrodes 2. After the inside of the vessel 1 is evacuated to a vacuum, the gaseous Ar is introduced into the vessel from an introducing pipe 7. A voltage is impressed to the electrodes 2, 3 from a power supply 4 to generate the plasma discharge, by which the gaseous Ar is ionized. 100Hz AC voltage is simultaneously impressed to a coil 5 on the outer periphery of the reaction chamber to generate the magnetic field orthogonal with the electric field generated between the electrodes 2 and 3 so that the stabilized zirconia on the surfaces of the electrodes 2 are bombarded by the gaseous Ar ions to granulate the zirconia. The thin films of the stabilized zirconia having the uniform thickness are thus formed with the high efficiency on the surfaces of the substrates 10.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to the surface of substrates such as solar cells, thin film semiconductors, television liquid crystals, electrophotographic photoreceptors, or porous substrates of fuel cells. The present invention relates to an apparatus for forming a thin film on a substrate.

[Conventional technology]

FIG. 3 schematically shows a typical sputtering apparatus that has been used conventionally (for example, as described in Japanese Patent Publication No. 55-26710).

In the figure, 01 is a cylindrical vacuum container with a base material 0 in the center.
2 is supported and arranged by the holder 03. An anode electrode 04 is placed on a concentric circle surrounding this base material 02, and a cylindrical cathode electrode (target) 05 is further placed concentrically around its outer periphery. Note that 06 is a permanent magnet and 07 is a power source.

When the inside of the vacuum container 01 is made into a predetermined low-pressure gas atmosphere and a suitable excitation voltage is applied between the anode electrode 04 and the cathode electrode 05 to generate a glow discharge, a cathode sputtering phenomenon occurs, and the sputtered cathode electrode - atoms or molecules adhere and deposit on the surface of the base material 02.

FIG. 4 shows an apparatus for forming a film of stabilized zirconia, which is a material for fuel cells. This is the so-called vacuum source□
Zirconium chloride (zrCL)
, yttrium chloride (HCI3) and water vapor (H2
O) is used.

Solid zirconium chloride 0
9 and yttrium chloride 010, and heater 011.
to 800 to 1000°C to generate metal vapor. These metal vapors together with the argon gas 013 introduced from the carrier gas introduction pipe 012
is transported to a reaction vessel 015 via a pipe 014.

On the other hand, water vapor 016 is generated by a water vapor generator (not shown), and is sent to the porous base material 018 via a second pipe 017.
It is injected from the back side of the base material 018 and reaches the front side of the base material 018 through the inside thereof.

Note that the sides of the base material 018 are sealed with a masking material 019 to prevent water vapor 016 from passing through.

On the front side of the base material O18, the vapors of zirconium chloride 09 and yttrium chloride 010 carried by the carrier gas, and water vapor 6 are mixed, and a chemical reaction shown by the following formula occurs, ZrCl4 + 2H 0- + ZrQt +
4HC12YC1s + 3H! O → YxOs
+6HC1 Zirconium oxide (zrot: zirconia), yttrium oxide (Y*Os) and chlorine gas (HCI) are produced.

These zirconium oxide and yttrium oxide are used as base materials.
As the water vapor 016 is deposited on the base material 018, it becomes difficult to pass through the base material 018, but since the oxygen ions 02- move, zrclj + 02 −+ zrQi −1 continues.
-2(It4YC13+ 30寞→2Yzo3+ 5
A reaction designated CIs takes place.

In this way, stabilized zirconia (ZrOz)o,9t(YzO,)o,09 is formed on the base material 018.

Note that the reaction residual gas and products (hydrochloric acid and chlorine) in the reaction vessel 015 are discharged from the third pipe 020 via the suction pump 021.

[Problem that the invention seeks to solve]

In the conventional sputtering apparatus shown in FIG.
An anode electrode 04 is placed on a concentric circle surrounding the anode electrode 2, and a cylindrical cathode electrode (target) 05 must be placed concentrically around the outer circumference of the anode electrode 04, so it is necessary to process a large number of base materials 02 at once. In this case, the vacuum container 01 becomes large.

In addition, in the method for forming a stabilized zirconia film shown in Fig. 4, zirconium chloride and yttrium chloride vapor and water vapor are used;
Corrosion-resistant broken glass must be used for auxiliary equipment such as the reaction vessel 015 and the gas suction pump 021, which is often inconvenient for practical purposes such as handling.

■ Because it is difficult to control the film thickness of stabilized zirconia,
A fairly thick film of 0 to 300 μm is formed, and only solid electrolytes with high resistance to oxygen ion movement can be produced.

There are problems such as.

[Means for solving problems]

The film forming apparatus of the present invention includes a reaction vessel containing a substrate, an even number of electrodes arranged parallel to the substrate on a concentric circle surrounding the substrate, and sputtering between adjacent objects of these electrodes. A thin film of atoms or molecules of the electrode material is formed on the outer peripheral surface of the base material.

In addition, as an apparatus for forming a thin film of stabilized zirconia on the outer circumferential surface of a base material, first, every other electrode of the even number of electrodes is coated with stabilized zirconia, and then the base material is coated with stabilized zirconia. zirconium electrodes and divalent or trivalent metal oxide electrodes arranged alternately on concentric circles surrounding the same cylindrical base material parallel to the base material, There is provided an AC power source that supplies sputtering power between the electrodes, and a gas supply device that supplies oxygen gas into the reaction vessel.

Furthermore, the present invention provides a film forming apparatus equipped with a coil that surrounds the electrodes and generates a magnetic field in a direction perpendicular to the electric field generated between the electrodes.

[For production]

In this invention, an even number of electrodes are arranged parallel to the base material on a concentric circle surrounding the base material, and power for sputtering is supplied between adjacent electrodes.

Therefore, one of the adjacent electrodes becomes a cathode electrode, that is, a target electrode, and the atoms or molecules of the material fly out and adhere to the surface of the base material.

In particular, if an even number of electrodes in which every other electrode is coated with stabilized zirconia is used, a thin film of stabilized zirconia is formed on the surface of the substrate.

On the other hand, zirconium ring electrodes and divalent or trivalent metal oxide electrodes are alternately arranged as electrodes, and alternating current power for discharge is supplied between these electrodes, and the inside of the container is When oxygen gas is introduced, the electrodes alternately act as cathodes and anodes, and zirconium and divalent or trivalent metal oxides are released and ionized and radicalized by plasma. Subsequently, the oxygen gas introduced into the container and zirconium combine to produce zirconia, and the oxide is also solid-dissolved to form a stabilized zirconia film on the base material.

Note that if the magnetic field is varied by the coil, the emitted ion particles etc. will be uniformly diffused.

〔Example〕

The present invention will now be described with reference to an embodiment of the apparatus shown in FIG.

1 is a reaction container, and a cylindrical base material 10 is placed in the center thereof. Reference numeral 2.3 denotes electrodes for generating plasma, which are arranged alternately and in parallel on concentric circles surrounding the base material 10. Furthermore, on the surface of the electrode 2, there is a film of stabilized zirconia.
It is formed by a method such as thermal spraying.

Reference numeral 4 denotes a first power source, which uses a commercial frequency of 60 Hz, for example, and is connected to the electrode group made up of the electrodes 2.3 so that the alternating and tk poles are changed. The coil 5 surrounds the reaction vessel 1 and is connected to a second power source 6. Reference numeral 7 denotes a plasma reaction gas introduction tube, which supplies, for example, argon gas to the reaction vessel 1.

Note that the exhaust hole 8 communicates with a vacuum pump 9, and the pressure inside the reaction vessel 1 is reduced.

After the vacuum pump 9 is driven to exhaust the inside of the reaction vessel 1 to a predetermined low pressure, argon gas is supplied from the plasma reaction gas introduction pipe 7.

Fill the reaction vessel 1 with the above argon gas and reduce the pressure to 0.
．． When the voltage is maintained at 0.05 to 5 Torr and a voltage is applied to the electrodes 2.3 from the first power source 4, glow discharge plasma is generated between the electrodes 2.3.

On the other hand, an AC voltage of, for example, 100H2 is applied to the coil 5 to generate a magnetic field B in a direction perpendicular to the electric field E generated between the electrodes 2 and 3. Note that the magnetic flux density may be about 10 Gauss.

The gas supplied from the plasma reaction gas introduction pipe 7 is excited by the electrons between the electrodes 2 and 3 and becomes plasma. Charged particles such as argon ions in the plasma are caused by the electric field E between the electrodes 2.3.

Coulomb force F+ = q E and Lorentz force p, = q (vxB) This causes EXB drift movement.

Note that ■ is the speed of charged particles.

Between the electrodes 2 and 3 where the electric field E is very large, the charged particles directly hit the electrodes 2 or 3 and cause sputtering.

As a result of this sputtering, stabilized zirconia molecules released from the electrode 2 become ionic particles or radical particles.

However, in a discharge space where the influence of the magnetic field E is small, the above KX
It flies out in a direction perpendicular to the electrode 2.3 with an initial velocity given by the B drift, and flies in a Larmor orbit due to the cyclotron motion caused by the magnetic field B generated by the codile tide.

Therefore, the charged particles emitted from the stain electrode 2 by sputtering reach the base material 10 and form a film on its surface.

At this time, since the radical particles collide with the charged particles flying in the Larmor orbit, the film is formed not only in front of the electrode 2.3 but also in a form that spreads to the left or right. Moreover, since the magnetic field B is varied, it is possible to uniformly form a film on the surface of the base material 10.

In this embodiment, unlike the conventional method, hydrochloric acid (HOI) is not generated, so there is no need to consider the corrosion resistance of the equipment.

Additionally, a thin film of stabilized zirconia is formed with significantly less damage than when thermal spraying is applied directly onto the substrate.

Furthermore, in this example, since the stabilized zirconia film is formed by so-called plasma sputtering, it is possible to control the film formation rate, and it is possible to form a solid electrolyte with low resistance to oxygen ion movement. can.

In addition to forming stabilized zirconia, if the electrode 2 side is used as a target electrode made of a desired metal and the electrode 3 side is used as an anode, the power source may be DC, and a film of atoms or molecules of the desired metal material can be used. can be formed into a film.

Furthermore, the length of the electrode 2.3 can be made as long as the length of the reaction vessel 1 allows without any problem, so even if a long base material is used, a uniform amorphous thin film can be formed on the surface of the base material. It becomes possible to do so.

FIG. 2 shows an example of an apparatus that can process a plurality of substrates at once.

As shown in the figure, the electrodes 2.3 are arranged in a honeycomb (hexagonal) shape, and the base material 10 is placed in the center thereof.

Therefore, one electrode mainly acts on three base materials 10, and the device can be made more compact. Although not shown, the electrodes 2.3 may of course be arranged in a grid pattern. In this case, the uniformity of the film thickness is slightly inferior to that of the honeycomb structure, but the compactness is further improved.

Next, a method of forming another stabilized zirconia thin film provided by the present invention will be explained.

As for the apparatus, either the one shown in FIG. 1 or the one shown in FIG. 2 can be used.

That is, the electrode 2 is made of zirconium, and the electrode 3 is made of yttrium oxide.

Further, an AC power source is used as a power source for supplying power for sputtering between the electrodes 2 and 3, and oxygen gas is supplied together with argon gas.

By doing so, the same reaction as in the vacuum evaporation described above in the conventional example occurs, and a thin film of stabilized zirconia can be formed on the surface of the material.

Although yttrium oxide was used as the oxide of a divalent or trivalent metal, yttribium oxide (Y fan○,)
It is also possible to form stabilized zirconia using calcium oxide (Cab) or calcium oxide (Cab).

〔Effect of the invention〕

According to this invention, a uniform thin film can be formed on the surface of a substrate, and therefore it is extremely valuable industrially.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an apparatus showing an embodiment of the present invention;
FIG. 2 is a cross-sectional view of a device showing another embodiment of the present invention. FIGS. 3C and 4 are explanatory diagrams showing conventional devices. l... Reaction container, 2.3... Electrode, 4... First power source, 5... Coil, 6... Second power source, 7...
Plasma reaction gas introduction pipe, 8... Exhaust hole, 9... Vacuum pump, 1o... Base material.

Claims (6)

[Claims] (1) Power for sputtering is supplied between a reaction vessel containing a substrate, an even number of electrodes arranged parallel to the substrate on a concentric circle surrounding the substrate, and objects next to these electrodes. 1. A film forming apparatus comprising a power source and forming a thin film of atoms or molecules of the electrode material on the outer peripheral surface of the base material. (2) Power for sputtering is supplied between the reaction vessel that houses the base material, an even number of electrodes arranged parallel to the base material on a concentric circle surrounding the base material, and the objects next to these electrodes. It comprises a power source and a coil that surrounds the electrode and generates a magnetic field in a direction perpendicular to the electrolysis generated between the electrodes, and forms a thin film of atoms or molecules of the electrode material on the outer peripheral surface of the base material. Characteristic film forming equipment. (3) The film forming apparatus according to claims (1) and (2), wherein every other electrode of the even number of electrodes is coated with stabilized zirconia. (4) The film forming apparatus according to any one of claims (1) to (3), wherein the sputtering power is alternating current. (5) A reaction vessel containing a base material, zirconium electrodes and divalent or trivalent metal oxide electrodes arranged alternately on concentric circles surrounding the base material parallel to the base material, and adjacent to these electrodes. It has an AC power source that supplies power for sputtering between the electrodes, and a device that supplies oxygen gas into the reaction vessel,
A film forming apparatus characterized in that a thin film of stabilized zirconia is formed on the outer peripheral surface of the base material. (6) Claims (1) to (5) characterized in that the electrodes are arranged in a grid or honeycomb, and the base material is placed at the center of the grid or honeycomb.
The film forming apparatus described in Section 1.