JP4351777B2 - Deposition assist deposition apparatus and thin film forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel deposition assist deposition apparatus for performing high-frequency ion plating deposition that directly applies a high frequency to a substrate, and a method for forming a high-quality thin film under conditions improved by the apparatus.
[0002]
[Prior art]
An ion plating vapor deposition method and apparatus for directly applying a high frequency to a substrate are disclosed in Japanese Patent Publication No. Hei 1-448347 as a “gasless ion plating vapor deposition machine”. This vapor deposition machine is a vapor deposition machine that does not use an inert gas such as argon and excites molecules or atomic particles made of an evaporation material by high frequency near the base material to form a well-distributed plasma and adhere to the base material. . In order to protect the plasma formed at this time from fluctuations such as abnormal discharge and stabilize the discharge, a capacitor is formed on the holder that fixes the base material, and the electric fluctuation is absorbed by the capacitance, so that the high vacuum can be used. Achieves gas-free ion plating deposition. (See Figure 4)
[0003]
However, in the prior art including the disclosed example, the substrate on which the thin film is to be formed is exposed to an environment in which the temperature is increased by radiation heat from a heat source for evaporating the film forming material from the evaporation source. This temperature rise reaches nearly 150 ° C. on the substrate surface in a process that requires a long deposition time. Therefore, when a film is formed on a base material that easily changes in quality at a high temperature, only a very limited thin film can be formed, such as a single layer coating of a metal mirror that is not affected by radiant heat.
[0004]
On the other hand, as an energy for evaporating the material of the evaporation source, not only thermal energy but also a method using an electron beam has been devised recently. However, when this method is used in a gas-free ion plating apparatus or similar ion plating apparatus, fluctuations in the electron beam occur, and the lifetime of the thermoelectron generating filament of the electron gun to be generated is continually practical. It gets shorter. That is, among the particles in the plasma formed between the substrate and the evaporation source, the vapor deposition particles are attracted and attached to the substrate, but one electron is attracted to the electron gun filament to stabilize the plasma discharge. The more the discharge power is increased, the more the electrons are concentrated on the filament, and the filament addition becomes large, leading to the destabilization of the irradiation position of the electron beam and the shortening of the filament life.
[0005]
[Problems to be solved by the invention]
The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide an ion plating apparatus capable of forming a thin film on a substrate without increasing the substrate temperature.
[0006]
Furthermore, the present invention is an apparatus and method capable of forming a desired film on a base material that can be selected from a wide range of materials, even if the base material is a material that easily changes in quality at a high temperature, not to mention an ordinary material. The purpose is to provide. It is another object of the present invention to provide an apparatus and a method capable of forming a dense and highly adhesive film on a wide variety of base materials with a wide range of film forming materials.
[0007]
It is another object of the present invention to provide an ion plating apparatus which has excellent operability by which stable plasma can be formed and conditions for high film formation speed can be set easily and continuously.
[0008]
[Means for Solving the Problems]
The present invention is a high-frequency ion plating vapor deposition apparatus that forms plasma consisting of at least a vapor deposition material. The conventional technique uses a plasma energy of a rare gas element such as argon, but the present invention is characterized in that it is possible to use only the plasma of the vapor deposition material. Of course, even if these rare gas elements are used in combination, there is no problem if it is preferable among various selection conditions. Therefore, the apparatus of the present invention may be provided with means for supplying an inert gas such as these rare gas elements.
[0009]
The present invention includes a vacuum chamber in which the vapor deposition of the present invention is performed and various necessary members or means are arranged. The chamber is not grounded, and this is one of the important structures for concentrating the electrons in the evaporation source boat, which is further characterized in the present invention described later.
[0010]
In the chamber, a grounded boat for storing an evaporation source to be a raw material for the deposited film is disposed. The fact that the boat is grounded is another important configuration for concentrating the aforementioned electrons on the evaporation source boat.
[0011]
The boat includes a means for heating the boat, and the evaporation material stored in the boat can be heated and evaporated. The heating means is not particularly limited in its configuration method, but the boat may be made of an electric resistor, and a current may be supplied to the boat itself to generate Joule heat. A heating element is embedded in the boat or heat is generated on the back of the boat. What is necessary is just to take the structure of sticking a body and making it heat-transfer.
[0012]
The chamber further includes a substrate holding means made of a conductive member that holds a substrate on which a vapor deposition film is to be formed. The base material holding means is insulated from the chamber, and is supported at a substantially upper center of the chamber by a supporting means with an insulating member interposed therebetween.
[0013]
The support means is made of a conductive member, and has the same potential as the chamber. The support means is paired with the base material holding means to form a capacitor with the insulating member sandwiched between them. Support in.
[0014]
The present invention further includes a high-frequency power supply power source disposed outside the chamber, and having one output pole connected to the substrate holding means via a DC shielding filter via an impedance matching device for supplying high-frequency power. The other one pole of the output of the high frequency power supply power source is grounded. As a result, high frequency power can be directly supplied to the substrate held by the substrate holding means, and stable plasma can be formed at a desired portion in the chamber. Of course, it is desirable that the high-frequency output is variable so that desired operation conditions can be set. The impedance matching device may be a well-known tuning circuit combining inductance and conductance, or may be another equivalent circuit.
[0015]
The present invention further includes a DC voltage application power source in which the cathode is connected to the substrate holding means via the high frequency shielding filter and the anode is grounded. As a result, the positively charged or cationized particles evaporated from the evaporation source fly in the direction of the base material, collide with the base material, and deposit to form a film. One electron, which is a negatively charged particle, is the counter electrode of the substrate holding means and is grounded, so that it flies intensively and intensively in the direction of the evaporation source boat that is applied positively, and reaches the evaporation source on the boat. Collides and gives energy to the evaporation source. Thus, the evaporation source that has obtained high energy instead of thermal energy easily evaporates into the plasma formation region in the chamber even at a low temperature. Of course, it is desirable that the applied voltage of the DC voltage application power source be variable so that desired operation conditions can be set, such as adjustment of the flying energy of particles.
[0016]
When the configuration of the present invention is adopted, the chamber itself in which the evaporation source boat and the like are disposed is insulated from the ground regardless of the electrode, so that the electrons in the chamber are scattered and scattered on the chamber wall. As a result, the electron beam is not neutralized and disappears, and substantially all of the electrons are concentrated on the evaporation source boat, resulting in a high-density electron beam.
[0017]
Further, in the present invention, a large amount of evaporation source particles that can be controlled in this way are collided with the substrate with controllable energy, so that not only mere flying deposition of the vapor deposition material on the substrate surface but also the substrate The film formed is dense because it has the energy to rearrange the molecules or atomic arrangement of the deposited material layer formed on the surface in a stable state, or even has room to adapt to penetration into the substrate. It is characterized in that a high quality product with excellent adhesion can be obtained.
[0018]
By enabling the above-described features of the present invention to be expressed by the above-described configuration, the present invention provides an excellent ion plating apparatus, that is, a deposition assist vapor deposition apparatus, which has never been obtained.
[0019]
The boat heating means of the present invention preferably includes a temperature adjusting means, and the evaporation source boat preferably includes an electronic concentration adjusting means. The temperature adjusting means of the heating means may be simply adjusting the current or voltage applied to the boat or the heating element. This makes it possible to set operating conditions in consideration of the heat resistance of the substrate. The electron concentration adjusting means may adjust the plane area of the boat for adjusting the electron beam irradiation area of the evaporation source, or may be provided with a diaphragm or a slit in front of the boat. In some cases, an electron lens or a path changing means combining an electric field and a magnetic field is also possible. If the combination of heating energy and electron irradiation energy can be set freely in this way, a wide range of evaporation sources can be deposited on a wide range of materials, and various thin films can be applied to various materials. It is possible to provide a material that forms the material, and the industrial utility value is increased.
[0020]
Furthermore, the present invention relates to a thin film formation method by high-frequency ion plating vapor deposition that forms a plasma consisting of at least a vapor deposition material. The vaporization source is heated by colliding electrons in the vacuum chamber. Evaporate, supply high-frequency power as plasma formation energy to the substrate disposed in the chamber, apply a DC voltage as particle kinetic energy, and cause electrons in the chamber plasma to concentrate and collide with the evaporation source on the boat Thus, the evaporation source can be evaporated at a low temperature, and a vapor deposition material is vapor-deposited on the base material so as not to raise the base material temperature, thereby forming a dense and closely adhered thin film.
[0021]
More specifically, the method of concentrating and colliding electrons with the evaporation source is described as follows: the base material is a single pole of a high-frequency power supply and a cathode of a DC voltage, and the evaporation source boat is the other single-pole of the evaporation source high-frequency power supply and a DC power supply. The anode is grounded as an anode, and the chamber is insulated from the ground.
[0022]
The frequency of the high-frequency power to be supplied is generally around 13.5 MHz, but is not particularly limited. The material of the target substrate, the material of the evaporation source, the setting specification of the thin film to be formed, the required film formation speed A frequency with good operability should be selected according to the above. At the same time, the output is generally 150 to 200 mW, for example, but it may be out of this range from the same viewpoint as described above.
[0023]
The direct-current voltage applied to the base material brings about the above-described effects. In the present invention, the voltage is not particularly limited. However, the base material, the evaporation source substance, and the thin film to be formed are also defined. Should be selected according to the relationship between the set specifications, the required film formation speed, and other operating conditions.
[0024]
A major feature of the present invention is that a thin film can be formed on a base material without increasing the temperature of the base material. The thin film can be formed at a substantially normal temperature, more specifically 100 ° C. or lower, preferably 40 ° C. or lower. It is formed. Thereby, it is significant as a technique desired for practical use such as a new surface coating of a plastic optical member, for example, a new anti-reflection coating or a new hard coating on a camera lens or a spectacle lens.
[0025]
The in-chamber plasma of the present invention can be a plasma made only of an evaporation material, but at least one kind of inert gas plasma may be further added depending on the purpose. Furthermore, it is possible to form not only a rare gas but also a gas such as nitrogen to form a nitride film, or to introduce a compound gas such as silane to form a related compound film. There is no hindrance.
[0026]
The present invention is characterized in that the substrate temperature can be controlled. However, since the influence on the substrate temperature is due to the radiant heat generated from the evaporation source boat, it is necessary to adjust the substrate temperature appropriately. is there. However, it is necessary to evaporate the evaporation source from the evaporation source at a predetermined speed in order to deposit the film on the substrate at a predetermined speed. Therefore, it becomes necessary to adjust the concentration of electron beams. That is, the present invention is characterized in that an appropriate balance between electron beam energy and heating energy is achieved. Therefore, the present invention adjusts the temperature of the evaporation source boat and the amount of electrons concentrated on the evaporation source boat to control the thin film formation rate at the desired substrate temperature or the substrate temperature at the desired thin film formation rate. And For example, when forming a thin film with a low melting point evaporation source such as magnesium fluoride or silicon dioxide, increase the area of the evaporation source. When forming a thin film with a high melting point evaporation source such as alumina, titanium oxide or zirconia, increase the area of the evaporation source. The degree of assist by electrons can be adjusted by narrowing.
[0027]
Since the present invention can form a thin film under a wide range of conditions as described above, a wide range of evaporation sources and a wide range of substrates can be selected. More specifically, in the present invention, the base material is glass, ceramics, metal, plastics, and the evaporation source is an inorganic compound such as a metal, metal oxide, or metal salt, and an organometallic polymer compound such as organopolysiloxane. It is a molecular compound.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on examples with reference to the drawings. FIG. 4 is a conceptual diagram showing a conventional ion plating vapor deposition machine.
[0029]
[Example 1]
FIG. 1 is a conceptual diagram showing a deposition assist vapor deposition apparatus of the present invention. 11 is a chamber that can be evacuated and is not grounded. 1 is grounded by an evaporation source boat, and a current is supplied to the boat by a heating power source 3 to generate heat. An evaporation source 9 receives heat from the boat and evaporates into a vacuum chamber. Reference numeral 2 denotes a base material holding means and a support means, which serve as terminals for holding the base material 10 in the chamber and supplying high frequency power to the base material 10 and applying a DC voltage. A high frequency power source 5 is connected to the substrate holding means through a matching device 4 and a condenser 7 as a DC shielding filter, and the other is grounded. 6 is a direct current power source, the negative side of which is connected to the substrate holding means through a coil which is a high frequency shielding filter, and the positive side is grounded.
[0030]
The evaporation source, that is, the vapor deposition material 9 placed on the evaporation source boat 1 is heated by the current of the heating power source 3 to evaporate, thereby generating evaporation particles composed of the evaporation source, that is, the coating material. A high frequency with an output of 50 to 800 mW and a frequency of 13.56 Mhz is added to the base material according to the above configuration, and the evaporated particles that have reached the base metal are ionized. The evaporated particles including the ionized particles are attracted and attached to the surface of the substrate by a DC bias applied to the substrate.
[0031]
On the other hand, the dissociated electrons are attracted to the evaporation source side opposite to the substrate. At this time, since the evaporation material is evaporating one after another from the evaporation source, the light emitter is seen in the vicinity of the evaporation source in such a form that it collides with the attracted electrons and the plasma foot falls to the evaporation source. The electrons collected near the evaporation source are sucked into the evaporation source boat that is grounded. At this time, the evaporation material is placed on the evaporation source boat and the heating and evaporation is proceeding. However, when the flying electrons are sucked, the evaporation material is sputtered and the evaporation is further promoted.
[0032]
When such a situation appears and the plasma stabilizes, the evaporation material of the evaporation source evaporates so that it is sucked up by the plasma. Therefore, in order to keep the deposition rate of the evaporation material adhering to the substrate constant, the heating current of the boat is set. And adjust the evaporation rate by heating. The sputtered and evaporated particles are similarly ionized and adhere to the substrate. The dissociated electrons fly to the evaporation source and contribute to the next sputtering. When stabilized by this repetition, the heating source current value can be kept low, evaporation of the vapor deposition material is continuously maintained at a lower heating temperature than the conventional one, and the deposition assist effect of the present invention is exhibited. .
[0033]
That is, if the evaporation rate = (evaporation rate by heating) + (evaporation rate by the deposition assist effect) is maintained and the deposition assist effect is increased, the radiant heat from the evaporation source is suppressed and the influence on the substrate is reduced. Therefore, a thin film could be formed without increasing the temperature of the substrate, and in the case of this example, the coating could be continued while maintaining a temperature of 30 ° C. or lower.
[0034]
In order to compare the adhesion and denseness of the thin film coated in accordance with the present invention to the base material with the method of the prior art, a wear test was performed on a sample on which a titanium oxide / silicon oxide multilayer coating was deposited by both methods. The results of the above are shown in FIG. A is the conventional method and B is the method of the present invention. The test method is a photomicrograph of the surface after applying a load of 2 kg to the standard eraser for inspection and reciprocating 200 times. As a result, it was found that although the coating film of the present invention had some scratches, no peeling occurred, and the hardness adhesion was remarkably improved.
[0035]
FIG. 3 is a graph in which the temperature change of the evaporation source and the substrate is traced according to the time of operation in comparison between the prior art and the technique of the present invention. Thus, it can be seen how the apparatus and method of the present invention can proceed with vapor deposition while maintaining a low temperature.
[0036]
[Example 2]
In the present invention, the deposition assist effect can be arbitrarily set by changing the density of the flying electrons by changing the area of the evaporation source.
[0037]
When an evaporation source with a small area is used, the density of flying electrons increases, so the deposition assist effect by sputtering increases, and good results are obtained for vapor deposition of refractory materials. In addition, since the flying electrons are dispersed and lowered in an evaporation source having a large area, the deposition assist effect acts gently, and good results were obtained for the deposition of a low melting point coating material or a polymer organic material.
[0038]
【The invention's effect】
The present invention has made it possible to provide an apparatus and a method capable of forming a desired film on a base material, which can be selected from a wide range of materials, even when the base material is easily deformed at a high temperature. Furthermore, the present invention has made it possible to provide an apparatus and a method capable of forming a dense and highly adhesive film on a wide variety of materials with a wide range of film forming materials. Furthermore, the present invention has made it possible to provide an ion plating apparatus with excellent operability that can form a stable plasma and can easily and continuously set conditions at a high film formation rate.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of an example of an apparatus for carrying out the present invention.
FIG. 2 is a photomicrograph comparing the adhesion and denseness of a thin film coated by the practice of the present invention to a substrate according to a conventional technique.
FIG. 3 is a graph in which the temperature change of the evaporation source and the substrate is traced over time by comparing the present invention with the prior art.
FIG. 4 is a conceptual diagram of an example of an apparatus for carrying out the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Evaporation source boat 2 Base material holding means and support means 3 Heating power source 4 High frequency impedance matching device 5 High frequency power source 6 DC power source 7 DC shielding filter 8 High frequency shielding filter 9 Evaporation source 10 Base material A Photomicrograph B showing photomicrograph showing test results of coated surface according to the present invention

Claims (8)

In a high-frequency ion plating vapor deposition apparatus that forms a plasma consisting only of evaporated particle gas of at least one vapor deposition material,
An ungrounded chamber to be a vacuum, a grounded boat for storing an evaporation material to be a raw material for the vapor deposition film disposed in the chamber, a means for heating the boat, and a substrate on which the vapor deposition film is to be formed A substrate holding means comprising a conductive member to be held; a support means comprising a conductive member having the same potential as the chamber; and supporting the substrate holding means via an insulating member; and a high-frequency power supply power source, A high-frequency power supply power source and an anode which are configured to supply a high-frequency power directly to a base material by connecting to a high-frequency base material holding means via a direct current shielding filter via an impedance matching device for supplying a high-frequency power and grounding one pole By connecting the cathode and the cathode to the substrate holding means via a high frequency shielding filter, a DC voltage is applied between the substrate and the boat. Equipped with DC voltage source and the high frequency power supply for impedance matching apparatus, deposition assisted vapor deposition apparatus characterized by electrons chamber plasma was made to collide concentrated in the evaporation source on the boat.   2. The deposition assist deposition apparatus according to claim 1, further comprising plasma of at least one kind of inert gas, and further comprising means for supplying at least one kind of inert gas.   3. The deposition assist deposition apparatus according to claim 1, further comprising a temperature adjusting means for the boat heating means and an electron concentration adjusting means for the evaporation source.   In a thin film formation method by high-frequency ion plating vapor deposition that forms plasma consisting of at least one kind of vapor deposition material, the vaporization material is evaporated by heating an evaporation source and colliding electrons in a vacuum chamber. Low temperature by supplying high-frequency power as plasma forming energy to the substrate placed in the chamber, applying DC voltage as particle kinetic energy, and causing the electrons in the chamber to collide with the evaporation material on the boat. A method of forming a thin film, characterized in that the evaporation material can be evaporated in step (a), and the evaporation material is evaporated on the substrate so as not to raise the substrate temperature. The method of concentrating and colliding electrons with the evaporation source is to use the base material as one pole of a high-frequency power source and a DC voltage cathode, and the evaporation source boat as the other one pole of the evaporation source high-frequency power source and the anode of the DC power source. The thin film forming method according to claim 4, comprising:   6. The thin film forming method according to claim 4, wherein plasma of at least one kind of inert gas is further added.   5. The temperature of the evaporation source boat and the amount of electrons concentrated on the evaporation source boat are adjusted to control the thin film formation rate at a desired substrate temperature or the substrate temperature at a desired thin film formation rate. The thin film formation method of thru | or 6.   The base material is glass, ceramics, metal, or plastics, and the evaporation source is a polymer compound including an inorganic compound such as metal, metal oxide, or metal salt, and an organometallic polymer compound such as organopolysiloxane. The thin film forming method according to 4 to 7.

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