JPH08311646A - Thin film forming device using ion beam vapor deposition - Google Patents

Abstract

PURPOSE: To provide a device by which a thin film having good adhesion and surface roughness can be formed at a comparatively low temp. and with good productivity. CONSTITUTION: This device is provided with a vacuum vessel 16, a holder 20 disposed inside the vacuum vessel 16, an arc evaporation source 40 for vapor- depositing a cathode material 4 on a base material 22 held with the holder 20 and an ion source 80 for irradiating the base material 22 with an ion beam 84. Also, the arc evaporation source 40 has a gas-blowing mechanism 32 for blowing a reactive gas 34 that reacts with the constituent material of a cathode 2 of the evaporation source 40, on the front surface 2a of the cathode 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion vapor deposition thin film forming apparatus for forming a thin film on a surface of a substrate by using vacuum vapor deposition and ion irradiation in combination.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional example of this type of ion vapor deposition thin film forming apparatus. This apparatus includes a vacuum container 16 that is evacuated by a vacuum pump (not shown) via a vacuum exhaust port 18, and a holder 20 that is provided in the vacuum container 16 and holds a substrate (object to be processed) 22. , Vacuum container 1
An evaporation source 70 that is provided at the bottom of the base 6 and that vaporizes the evaporation material 76 on the base material 22 held by the holder 22; and a base material 22 that is attached to the bottom of the vacuum container 16 and held by the holder 20. And an ion source 80 for irradiating the ions 84.

The holder 20 and the substrate 22 may be rotated as shown by arrow A. The shape of the base material 22 is not limited to the one shown in the drawing, but may be any shape.

The evaporation source 70 is an electron beam heating type evaporation source, and heats the evaporation material 72 in the crucible 71 by an electron beam 74 drawn from an electron gun 73 to evaporate or sublime it (in the case of carbon). To generate the vaporized substance 76. The evaporation material 72 is made of an element (for example, a metal such as Ti or carbon) that forms a thin film formed on the base material 22.

The ion source 80 has a gas 8 introduced therein.
2 is ionized to extract ions 84 with a predetermined acceleration energy. As the ion source 80, for example, a bucket type ion source of a multi-pole magnetic field type is preferable in terms of a large area and a large current, but of course, an ion source of any other method may be used. The types of ions 84 extracted from the ion source 80 will be described later.

In forming the thin film, after the desired substrate 22 is held by the holder 20, the inside of the vacuum container 16 is held at a predetermined vacuum degree (for example, about 10 ^-5 to 10 ^-6 Torr).
Then, at the same time as, or alternately with, evaporating the evaporation material 76 composed of the element forming the thin film from the evaporation source 70 and depositing it on the surface of the base material 22, the required ions 84 are extracted from the ion source 80 and are then extracted. The substrate 22 is irradiated.

At this time, when a compound thin film is formed on the surface of the base material 22, ions 84 containing an element that combines with the vaporized substance 76 to form the compound thin film are irradiated to form a thin film other than the compound, for example, a simple metal. In the case of forming a thin film or a carbon-based thin film, an inert gas ion such as Ar ion is irradiated as the ion 84.

As a result, a thin film is formed on the surface of the base material 22 by vapor deposition of the evaporation material 76 or by combination of the evaporation material 76 and the irradiation ions 84.

At the same time, due to the pushing action of the irradiation ions 84 and the like, a mixed layer is formed in the vicinity of the interface between the base material 22 and the thin film, in which the elements forming the base material and the elements forming the thin film are mixed. Since this mixed layer acts like a wedge, the adhesion of the thin film to the base material 22 becomes high.

[00010]

The above-described ion-deposited thin film forming apparatus can form a thin film having good surface roughness (that is, excellent thin film surface smoothness) and good adhesion at a relatively low temperature. Although it has a feature that it can be formed, it has a drawback that it is not suitable for high-speed film formation and the productivity of a thin film is low.

This is because the ionization rate of the evaporation material 76 from the electron beam heating evaporation source 70 is as low as 10% or less, and when forming a compound thin film composed of a metal element and a non-metal element, a metal is used as the evaporation material 76. Of the metal and non-metal gas molecules (this gas is
6 is low in reactivity with the gas introduced into the chamber 6 or the gas injected into the vacuum vessel 16 from the ion source 80), and the progress of the reaction becomes insufficient as the film forming rate is increased. is there.

Further, the electron beam heating type evaporation source 70 is
It is necessary to prevent the evaporation material 72 from spilling out of the crucible 71 when it is melted, and it is only possible to evaporate from the bottom to the top, that is, to arrange the evaporation source 70 only below the substrate 22. Since this is not possible, there is a large restriction on the arrangement of the evaporation source 70, and thus a large restriction on the film formation direction with respect to the base material 22 and the apparatus configuration.

On the other hand, as the evaporation source, there is a conventional arc-type evaporation source for evaporating a cathode substance by utilizing arc discharge at a cathode.

In the arc type evaporation source, since the ionization rate of the evaporated substance is as high as about 70% or more, if such an arc type evaporation source is used instead of the electron beam heating type evaporation source 70, a compound thin film is formed. The progress of the reaction can be rapidly performed even at high-speed film formation, and the productivity can be improved.

Further, in the arc type evaporation source, since the cathode locally melts by the arc, the molten substance (molten metal) does not drop regardless of the direction of the evaporation source, and accordingly There are no restrictions on the placement of evaporation sources,
It can be mounted in any orientation. Therefore, such an arc type evaporation source is used as the electron beam heating type evaporation source 7
If it is used instead of 0, restrictions on the film forming direction with respect to the base material 22, the device configuration, etc. are reduced.

However, in the conventional arc-type evaporation source, the molten portion of the cathode is apt to be large, so that a large mass of the cathode material is simultaneously evaporated from the cathode together with the fine cathode material, and this is incident and deposited on the surface of the base material 22. However, there is a problem that the surface roughness of the thin film surface formed on the surface of the base material 22 is worse than that when the evaporation source 70 of the electron beam heating type is used.

Therefore, the present invention solves all the problems of the above-mentioned conventional techniques, and can form a thin film having good adhesion and surface roughness at a relatively low temperature with high productivity. The main object is to provide a thin film forming apparatus.

[0017]

In order to achieve the above object, the ion vapor deposition thin film forming apparatus of the present invention uses an arc discharge at a cathode as an evaporation source to evaporate a cathode material. It is characterized by being provided with an arc evaporation source having a gas spraying mechanism for spraying a reactive gas that reacts with the constituent substances onto the front surface of the cathode.

[0018]

According to the above arc type evaporation source, when arc discharge is performed while the reactive gas is blown from the gas blowing mechanism to the front surface of the cathode, a large number of arc discharge cathode points are generated on the front surface of the cathode to cause arc branching in the vicinity of the cathode. The arc discharge sites are dispersed in large numbers, a compound with a higher melting point than the original cathode constituents is formed on the cathode surface, and it suppresses the spread of the melted part. It is suppressed to a small size, and formation of a coarse melted portion on the front surface of the cathode is suppressed. As a result, it is possible to prevent generation of a large lump of the cathode material, thereby forming a thin film having good surface roughness on the surface of the base material.

Moreover, since it is an arc type evaporation source, the ionization rate of the evaporated substance is high, and therefore high speed film formation is possible and the productivity is high. Further, since the thin film is formed by using the vacuum deposition by the arc evaporation source and the ion irradiation in combination, the thin film having good adhesion can be formed at a relatively low temperature.

[0020]

1 is a schematic view showing an ion vapor deposition thin film forming apparatus according to an embodiment of the present invention. The same or corresponding portions as those in the conventional example of FIG. 11 are designated by the same reference numerals, and the differences from the conventional example will be mainly described below.

In this embodiment, an arc evaporation source 40 is provided in place of the conventional electron beam heating evaporation source 70 described above. That is, in this embodiment, the holder 20
An arc evaporation source 40 is attached to the side surface of the vacuum container 16 so as to face the substrate 22 held by the.

The arc-type evaporation source 40 is provided with a cathode 2 made of a desired material (for example, metal, alloy, carbon, etc.), a flange 6 for supporting the same, and a flange 6 made of a non-magnetic material, and arranged near the rear of the flange 6. It has an annular permanent magnet 8 and is attached to the vacuum container 16 via an insulator 12. Although a trigger electrode is also normally provided, its illustration is omitted here (the same applies to other examples). More specifically, the cathode 2 is made of an element (for example, a metal such as Ti, Cr, B, or the like, carbon, or the like) forming a thin film formed on the base material 22.

In this example, the vacuum container 16 also serves as an anode, and a DC arc power source 14 is connected between the flange 6 and the cathode 2 with the cathode 2 side being the negative side. An arc discharge voltage of, for example, several tens V to several hundreds V can be applied between the cathode 2 and the vacuum container 16.

The arc type evaporation source 40 further comprises a gas spraying mechanism 32 for spraying a reactive gas 34 that reacts with the cathode constituents from a position remote from the cathode 2 onto the cathode front surface 2a.
In the vicinity of the cathode 2. Gas blowing mechanism 32
Is the gas supply pipe 33 in this example.

The holder 20 is connected to the negative side of a DC bias power source 24 as in this embodiment.
A negative bias voltage of, for example, about several hundreds V may be applied to the base material 22 on 0. 23
Is an insulator. By doing so, the arc evaporation source 4
Since the ionized cathode material 4 from 0 can be drawn into the base material 22 by the bias voltage, the throwing power (that is, the cathode material 14 reaches the shaded portion) is improved. Further, since the ions 84 extracted from the ion source 80 can be easily accelerated by the bias voltage, it is possible to easily enhance the bombarding effect (that is, the cleaning effect) of the substrate surface by the ions 84.

The holder 20 and the base material 22 may be rotated as indicated by arrow A. By doing so, even if the base material 22 has a complicated shape, a thin film can be uniformly formed on the surface thereof.

A reactive gas 28 may be introduced into the vacuum vessel 16 from a gas source (not shown) via a gas introduction port 26 provided on the wall surface of the vacuum vessel 16.

The reactive gas 34 blown from the gas blowing mechanism 32 to the cathode front surface 2a is intended to prevent coarse particles from scattering from the cathode front surface 2a, and is, for example, nitrogen gas, methane gas or the like. is there. On the other hand, the reactive gas 2 introduced into the vacuum container 16 through the gas introduction port 26
8 mainly aims to supply the elements constituting the thin film formed on the surface of the base material 22 to the vicinity of the base material 22 instead of or together with the ions 84 supplied from the ion source 80. For example, nitrogen gas is used to form a nitride-based compound thin film, and methane gas is used to form a carbide-based compound thin film. Therefore, both reactive gases 28 and 34 may be the same or different from each other.

The gas 82 supplied to the above-mentioned ion source 80 is mainly for supplying the elements constituting the thin film formed on the surface of the base material 22 as the ions 84, for example, a nitride-based compound. Nitrogen gas is used to form a thin film, methane gas is used to form a carbide-based compound thin film, and oxygen gas is used to form an oxide-based compound thin film. Therefore, this gas 82 and the above-mentioned reactive gas 28
Both 34 and 34 may be the same or different from each other. Further, an inert gas such as Ar may be added to the gas 82 supplied to the ion source 80, which improves the ionization rate of a desired gas in the ion source 80. Alternatively, when a non-compound-based thin film such as a metal simple substance or a carbon-based film is formed, an inert gas is supplied as the gas 82 to extract the inert gas ions and irradiate the substrate 22 with the ions. Is also good.

In forming the thin film, the arc type evaporation source 40 is operated with the inside of the vacuum vessel 16 maintained at a predetermined vacuum degree to evaporate the cathode material 4 and then to form the base material 22.
The ion source 8 simultaneously or alternately with the deposition on the surface of the
The required ions 84 are extracted from 0 and irradiated on the substrate 22. At that time, the reactive gas 28 is introduced into the vacuum container 16 from the gas introduction port 26 as needed.

The operation of the arc evaporation source 40 is as follows. That is, when the above-mentioned arc discharge voltage is applied from the arc power supply 14 between the cathode 2 and the vacuum container 16, the first spark is generated in the vicinity of the front surface 2a of the cathode 2 by using a trigger electrode (not shown) or the like. As a result, an arc discharge is generated between the cathode front surface 2a and the vacuum container 16 as a trigger. Due to this arc discharge, the cathode front surface 2a is locally heated to a high temperature, the cathode front surface 2a is locally melted, and the cathode material 4 in the form of atoms and particles larger than that is evaporated from the base material 22. Reaches and deposits.

As a result, on the surface of the substrate 22, the cathode material 4 is vapor-deposited, or the cathode material 4 and the irradiation ions 8 are formed.
4 and the reaction gas 2
The addition of 8 forms a thin film.

At the same time, due to the pushing action of the irradiation ions 84 and the like, a mixed layer is formed in the vicinity of the interface between the base material 22 and the thin film, in which the elements forming the base material and the elements forming the thin film are mixed. Since this mixed layer acts like a wedge, the adhesion of the thin film to the base material 22 becomes high.

Further, the arc type evaporation source 40 has the gas spraying mechanism 32 as described above. When the reactive gas 34 is sprayed from the gas spraying mechanism 32 to the cathode front surface 2a, an arc discharge occurs. A large number of cathode points of arc discharge are generated on the cathode front surface 2a, arc branching occurs near the cathode and a large number of arc discharge sites are dispersed, and a compound having a higher melting point than the original cathode constituent substance is formed on the cathode surface. The effect of suppressing the spread of the melted portion and the like suppresses the volume of each melted portion to be small and suppresses the formation of a coarse melted portion on the cathode front surface 2a. As a result, it is possible to prevent the generation of a large lump of the cathode material 4, thereby forming a thin film having good surface roughness on the surface of the base material 22.

Moreover, since the arc evaporation source 40 is used in this embodiment, the ionization rate of the evaporation material, that is, the cathode material 4, is higher than that of the electron beam heating evaporation source.
Therefore, high-speed film formation is possible and productivity is high. Further, since the vacuum evaporation by the arc type evaporation source 40 and the ion irradiation of the ions 84 from the ion source 80 are used together to form a thin film, a thin film having good adhesion can be formed at a relatively low temperature. it can.

The term "relatively low temperature" as used herein means that the temperature is lower than that of the CVD method which requires high temperature heating of the substrate, and the specific temperature varies depending on the type of thin film to be formed. Although it cannot be said, for example, room temperature to several hundred degrees Celsius
It is a degree.

As described above, according to this ion-deposited thin film forming apparatus, a thin film having a good surface roughness can be formed with good productivity, so that it is inexpensive and requires a mirror finish, for example, a lens molding die. It can also be applied to the production of compact disc molds and the like.

When a conventional arc type evaporation source (that is, having no gas blowing mechanism) is used, the surface roughness of the film is deteriorated by increasing the film forming rate, and the cathode having a low evaporation rate is used. The material (for example, carbon, titanium, etc.) has a relatively good surface roughness of the deposited film, but there is a problem that the film forming rate is low and the productivity is poor. However, the arc type evaporation source 40 as in this embodiment is used. For example, no matter what kind of cathode is used, a thin film having excellent surface roughness can be formed at high speed.

Next, a description will be given of an embodiment further improved so that a thin film having a better surface roughness can be formed. FIG. 2 is a schematic view showing an example of such an ion vapor deposition thin film forming apparatus.

The differences from the embodiment shown in FIG. 1 will be mainly described. The arc type evaporation source 40 in this embodiment is
A plurality of rod-shaped permanent magnets 42 are arranged so that one magnetic pole of each of them faces the rear surface of the flange 6 and thus the rear surface 2b of the cathode 2, so that the polarities are different from each other near the rear surface of the cathode rear surface 2b. A plurality of magnetic poles are formed.

A detailed example of the arrangement of the permanent magnets 42 is shown in FIG. In this example, a plurality of rod-shaped permanent magnets 42 are arranged such that one magnetic pole of each of them is opposed to the cathode rear surface 2b, and N.
The poles and the S poles are arranged alternately. Reference numeral 44 denotes a support member which is made of a non-magnetic material and supports each permanent magnet 42.

According to such a magnet arrangement, the cathode front surface 2
A multi-pole magnetic field is formed by a large number of magnetic poles near a. This will be described in detail. In the vicinity of the cathode front surface 2a, as shown in FIG. 7 and a part thereof is enlarged and shown in FIG. 8, magnetic fields B oriented in a number of directions along the cathode front surface 2a, That is, a multi-pole magnetic field is formed.

On the other hand, in the case of the simple annular permanent magnet 8 used in the arc type evaporation source 40 in the embodiment shown in FIG. 1, it is along the cathode front surface 2a as shown in FIG. A simple radial magnetic field B, ie a single magnetic field, is formed.

In the case of a single magnetic field as shown in FIG. 6, the movement of electrons (which is caused by arc discharge) in the vicinity of the cathode front surface 2a is not so complicated, so that the gas is generated on the cathode front surface 2a. Even if the reactive gas 34 is sprayed from the spraying mechanism 32, the collision probability of the molecule and the electron does not become so large, and therefore the action of ionizing the reactive gas 34 and promoting the compound formation on the cathode front surface 2a is not so great. Not strong

In the case of a single magnetic field as shown in FIG. 6, the Lorentz force F due to the J × B effect (J is the current flowing through the arc, B is the magnetic field) near the cathode front surface 2a is
Since the arc discharge position is only moved (drifted) so as to draw a simple circle 58, the drift causes
The action of preventing the formation of a coarse melted portion on the cathode front surface 2a is not so strong. 36 indicates one state of the arc.

On the other hand, in the case of a multi-pole magnetic field as shown in FIGS. 7 and 8, for example, the movement of electrons in the vicinity of the cathode front surface 2a becomes more complicated than in the case of a single magnetic field, so that the The electron density near the front becomes high,
As a result, the probability of collision between the electrons and the molecules of the reactive gas 34 blown from the gas blowing mechanism 32 to the cathode front surface 2a increases, and the reactive gas 34 decomposes, ionizes,
Excitation is promoted. As a result, the reaction between the reactive gas 34 and the cathode constituent substance is promoted, and a high melting point compound (this is a compound having a higher melting point than the original cathode material. The same applies hereinafter) on the cathode front surface 2a. Is promoted, whereby the spread of the melted portion due to the arc on the cathode front surface 2a is strongly suppressed.

It can be said that this utilizes a kind of magnetron discharge in the vicinity of the cathode front surface 2a, and it is very effective in promoting the formation of compounds on the cathode front surface 2a, but a multipole magnetic field is used. If so, the effect is remarkable for the reasons described above.

In the case of a multi-pole magnetic field, the Lorentz force F due to the J × B effect near the cathode front surface 2a.
Is not a mere circle, but a plurality of small circles that are close to each other or partially overlap each other, as shown in FIGS. 7 to 9, for example. as a result,
The drift of the arc discharge position due to the Lorentz force F is not a mere circular shape, but becomes a complicated movement such as a trochoidal shape and a large circular shape as a whole as shown by the locus 59 in FIG. As a result, formation of a coarse melted portion due to an arc on the cathode front surface 2a is strongly suppressed.

The combination of the above two actions results in the cathode front surface 2a.
The formation of a coarse melted portion due to the arc in the above is more effectively and thoroughly suppressed. As a result, it is possible to more reliably prevent coarse particles from scattering from the cathode 2 and form a thin film having an extremely good surface roughness on the surface of the base material 22.

The permanent magnets 42 are preferably arranged as close to the cathode rear surface 2b as possible so that the magnetic force lines from them can effectively reach the cathode front surface 2a. If they are not brought close to each other, the number of permanent magnets 42 may be reduced to increase the distance between the magnets. This also applies to other examples described below.

The plurality of permanent magnets 42 are arranged such that the N poles and the S poles are arranged randomly, instead of the N poles and the S poles are arranged alternately as in the example of FIG. Even in that case, a multi-pole magnetic field is formed in the vicinity of the cathode front surface 2a, and therefore, the same operational effect as in the case of the example of FIG. 3 can be obtained.

Further, as in the example shown in FIG. 4, one or more annular permanent magnets 48 are concentrically arranged around the central permanent magnet 46, and one of the magnetic poles faces the cathode rear surface 2b. Alternatively, the plurality of magnetic poles having different polarities described above may be formed by arranging the N poles and the S poles alternately in the inner and outer directions of the ring. The term “annular” as used herein is a broad concept that includes a square annular shape and the like in addition to the annular shape as illustrated. Further, the central permanent magnet 46 may also be annular.

Also in the case of this example, a multi-pole magnetic field is formed in the vicinity of the cathode front surface 2a, whereby the cathode front surface 2a is formed.
Formation of a high melting point compound is promoted, and the drift of the arc discharge position due to the Lorentz force becomes a complicated movement such as a trochoidal shape, so that the formation of a coarse melted portion by the arc on the cathode front surface 2a is prevented. The effect is remarkable.

Further, in the plurality of rod-shaped permanent magnets 42 as described above, one of the magnetic poles faces the cathode rear surface 2b,
Further, those having the same polarity may be arranged in a concentric ring shape, and the N-pole group ring and the S-pole group ring may be arranged alternately in the inner and outer directions of the ring. The term “annular” as used herein is a broad concept including an annular shape, a rectangular shape, and the like. That is, a plurality of rod-shaped permanent magnets 42 may form a magnetic pole substantially similar to the example shown in FIG. Also in this case, the same effect as the example of FIG. 4 can be obtained.

Further, as in the example shown in FIG. 5, three electromagnets 50 are arranged so that one magnetic pole of each of them opposes the cathode rear surface 2b and around the predetermined center O every 120 degrees. They have three-phase alternating current (ie 120
A plurality of magnetic poles having different polarities described above may be formed by supplying alternating currents having different phases each time. In this example, each electromagnet 50 has a rod-shaped core 52 and a coil 54 wound around it.

In the case of this example, the magnetic field formed by the three electromagnets 50 rotates in the plane of the cathode front surface 2a, so that the arc discharge position is not only caused by the Lorentz force due to the J × B effect but also by the rotation of the magnetic field. Can be forced to rotate by. As a result, it is possible to effectively suppress the formation of a large melted portion due to the arc on the cathode front surface 2a.

If the frequency of the three-phase alternating current supplied to the electromagnet 50 is too high, the drift of the arc cannot follow the rotation of the magnetic field, so it is preferable to set it to about 10 Hz or less, and among them, about 1 to several Hz. More preferable.

By the way, the gas blowing mechanism 32 described above is used.
Is the gas supply pipe 3 as in the example shown in FIG.
3 is provided with a ring-shaped portion 60 surrounding a side of the cathode 2 in the vicinity of the front surface 2a of the cathode 2.
A plurality of gas outlets 62 may be arranged in a distributed manner, and more preferably, may be arranged in a substantially even manner. By doing so, the reactive gas 34 can be sprayed more evenly on the front surface 2a of the cathode 2, so that a larger number of cathode points of arc discharge can be dispersed on the cathode front surface 2a, or a high melting point compound can be formed on the cathode front surface 2a. Can be formed more uniformly, and thereby the formation of a coarse melted portion on the cathode front surface 2a can be suppressed more effectively.

When the cathode 2 is carbon (graphite), the carbon is not melted by the arc but is sublimated. At that time, in a conventional arc-type evaporation source (that is, having no gas blowing mechanism), when carbon sublimes, it snaps and a large lump is scattered (this is called bumping), which is the surface of the base material 22. The surface roughness of the thin film formed on the surface is deteriorated. On the other hand, in the arc evaporation source 40 in each of the above-described embodiments, the hydrogen gas as the reactive gas 34 is blown from the gas blowing mechanism 32 onto the cathode front surface 2a, so that the cathode front surface 2a has a vaporizable hydrocarbon. Since the system compound can be formed and evaporated in that state, scattering of coarse particles can be prevented.
Since hydrogen is released as a gas from the compound that has reached the base material 22, carbon is deposited on the surface of the base material.

The action of forming such a hydrocarbon compound can be obtained also in the arc type evaporation source 40 in the embodiment shown in FIG. 1, but it is shown in FIG. 2 and after rather than the case of using the single magnetic field. Arc type evaporation source 4 in the embodiment
As described above, a multi-pole magnetic field such as 0 can further promote decomposition, ionization, excitation, etc. of the reactive gas 34, so that a hydrocarbon-based compound can be formed more effectively. As a result, scattering of coarse particles can be suppressed more effectively.

Next, some more specific examples will be described.

Example 1 Using the apparatus of the example shown in FIG. 1, the inside of the vacuum chamber 16 was sufficiently evacuated to 1 × 10 ⁻⁵ Torr or less, and then a thin film was formed. Titanium (Ti) having a purity of 3N is used as the material of the cathode 2, and nitrogen gas (N ₂ ) is sprayed on the cathode 2 as the reactive gas 34.
Nitrogen gas was introduced as the gas 82 into the ion source 80 and nitrogen ions were extracted as the ions 84 to form a TiN film on the surface of the substrate 22.

A smooth film can be formed also in the conventional apparatus shown in FIG. 11 using the electron beam heating type evaporation source, but if the Ti vapor deposition rate exceeds 3 μm / hr,
The ratio of Ti and N becomes Ti / N> 1 and deviates from the stoichiometric composition. On the other hand, in the case of the device of this embodiment, not only a smooth film is obtained, but even if the deposition rate of Ti is 10 μm / hr, the ratio of Ti to N is Ti / N =
1 and a TiN film having a substantially stoichiometric composition was obtained.

Also, when the magnet arrangement of the arc evaporation source 40 in the apparatus of the embodiment shown in FIG. 2 is as shown in FIG. 3, the same result as above is obtained.

Example 2 Using the apparatus of the example shown in FIG. 1, the inside of the vacuum chamber 16 was sufficiently evacuated to 1 × 10 ⁻⁵ Torr or less, and then a thin film was formed. Chromium (Cr) having a purity of 3N is used as the material of the cathode 2, and nitrogen gas (N ₂ ) is sprayed on the cathode 2 as the reactive gas 34.
Nitrogen gas is also introduced into the ion source 80 as the gas 82, nitrogen ions are extracted as the ions 84, and methane gas (CH ₄ ) is introduced into the vacuum container 16 from the gas inlet 26 as the reactive gas 28 to produce CrCN. A film was formed on the surface of the substrate 22.

In the conventional apparatus using the electron beam heating type evaporation source shown in FIG. 11, when the Cr deposition rate exceeds 6 μm / hr, Cr / (C + N)> 1, but in the apparatus of this embodiment, , The above ratio was equal to 1 even when the deposition rate of Cr was 24 μm / hr, and the surface roughness of the obtained CrCN film was Ra = 0.05 μm (Ra is the maximum surface roughness).

Further, in the apparatus of the embodiment shown in FIG. 2, when the magnet arrangement of the arc evaporation source 40 is as shown in FIG. 3, the Cr vapor deposition rate is 24 μm / hr as in the above case.
But the above ratio is equal to the stoichiometric value of 1, and the obtained C
The surface roughness of the rCN film was improved to Ra = 0.03 μm.

Example 3 Using the apparatus of the example shown in FIG. 1, the inside of the vacuum chamber 16 was sufficiently evacuated to 1 × 10 ⁻⁵ Torr or less, and then a thin film was formed. Boron (B) is used as the material of the cathode 2, and nitrogen gas (N ₂ ) is blown as the reactive gas 34 to the cathode 2 and the ion source 80 is used.
Further, nitrogen gas was introduced as the gas 82 and nitrogen ions were extracted as the ions 84 to form a BN film on the surface of the base material 22.

The conventional apparatus shown in FIG. 11 using the electron beam heating type evaporation source also forms a smooth hexagonal, cubic or amorphous BN film, but it is necessary to use B for obtaining the stoichiometric composition. The upper limit of vapor deposition rate is as low as 0.5 μm / hr. On the other hand, in the case of the apparatus of this example, a smooth hexagonal, cubic or amorphous BN film is obtained, but the upper limit of the vapor deposition rate of B for obtaining a BN film having a stoichiometric composition is It was as high as 2 μm / hr.

When the magnet arrangement of the arc evaporation source 40 in the apparatus of the embodiment shown in FIG. 2 is as shown in FIG. 4, the surface roughness of the obtained BN film is Ra = 0.05 μm.
It was found that Ra was improved to 0.02 μm.

Example 4 Using the apparatus of the example shown in FIG. 1, the inside of the vacuum vessel 16 was sufficiently evacuated to 1 × 10 ⁻⁵ Torr or less, and then a thin film was formed. Aluminum (Al) is used as the material of the cathode 2, nitrogen gas (N ₂ ) is sprayed onto the cathode 2 as the reactive gas 34, and nitrogen gas is also introduced into the ion source 80 as the gas 82 to produce nitrogen ions as ions 84. The AlN film as the base material 22
Formed on the surface of.

The conventional apparatus shown in FIG. 11 using the electron beam heating evaporation source also forms a smooth AlN film.
Compared with the device of this example, the upper limit of the film formation rate for obtaining an Al film having a stoichiometric composition was as low as about 1/3.

Further, in the apparatus of the embodiment shown in FIG. 2, when the magnet arrangement of the arc evaporation source 40 is as shown in FIG. 5, the surface roughness Ra of the obtained AlN film is the same as that of the conventional apparatus. It was found to be 1/4 of that of Example 1, and the smoothness was further improved.

<Embodiment 5> Using the apparatus of the embodiment shown in FIG. 1, the interior of the vacuum vessel 16 was sufficiently evacuated to 1 × 10 ⁻⁵ Torr or less, and then graphite was used for the cathode 2 and sprayed on the cathode. Diamond-like carbon (DLC) was vapor-deposited on the surface of the base material 22 using the reactive gas 34 as hydrogen. At this time, a mixed gas of hydrogen gas and Ar gas is introduced into the ion source 80 as the gas 82, and hydrogen ions and Ar are introduced into the base material 22.
Irradiated with mixed ions with ions. Hydrogen ion is DL
It functions to remove the graphite in the C film by etching. The Ar gas acts to improve the ionization rate of hydrogen in the ion source 80.

Although the DLC film is formed even in the conventional apparatus using the electron beam heating evaporation source shown in FIG. 11, the upper limit of the DLC film forming rate is about 1 as compared with the apparatus of this embodiment. As low as / 5. That is, the upper limit of 1 μm / hr was obtained while the former was 0.2 μm / hr.

Even when the magnet arrangement of the arc type evaporation source 40 in the apparatus of the embodiment shown in FIG. 2 is as shown in FIG. 3, almost the same result as above is obtained.

[0077]

Since the present invention is configured as described above, it has the following effects.

According to the apparatus of the first aspect, since the arc type evaporation source having the gas blowing mechanism is provided, formation of a coarse melted portion on the front surface of the cathode is suppressed. As a result, it is possible to prevent evaporation of a large amount of cathode material,
As a result, a thin film having a good surface roughness can be formed on the surface of the base material.

Moreover, since the arc type evaporation source is used, the ionization rate of the evaporation material is high, and therefore high speed film formation is possible and the productivity is high. Further, since the thin film is formed by using the vacuum deposition by the arc evaporation source and the ion irradiation in combination, the thin film having good adhesion can be formed at a relatively low temperature.

Further, in the case of the conventional apparatus using the electron beam heating type evaporation source, there is a problem that the composition of the film changes when the film formation speed is increased, and a compound thin film having a stoichiometric composition cannot be obtained. Further, when a film is formed using an evaporation material having a low evaporation rate, the film composition varies little, but the film forming rate is low, and as a result, there is a problem in that productivity is poor. According to this, no matter what material is used for the cathode of the arc evaporation source, it is possible to form a thin film having a high surface roughness at a high speed.

According to the apparatus of claims 2 to 7, the following further effects are obtained. That is, a multi-pole magnetic field is formed in the vicinity of the cathode front surface of the arc evaporation source, thereby promoting the reaction between the reactive gas and the cathode constituents in the vicinity of the cathode front surface, and in the cathode front surface, a melting point higher than that of the original cathode material. Since the formation of the compound and the formation of the hydrocarbon compound in the case of the carbon cathode are promoted, the melting and scattering of the coarse particles from the cathode is strongly suppressed. Moreover, the Lorentz force between the magnetic field and the arc current strongly promotes the drift of the arc discharge position, so that the formation of the coarse melted portion due to the arc on the front surface of the cathode is strongly suppressed. Combined with these effects, it is possible to more reliably prevent coarse particles from scattering from the cathode, and to form a thin film having extremely good surface roughness.

[Brief description of drawings]

FIG. 1 is a schematic view showing an ion deposition thin film forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an ion deposition thin film forming apparatus according to another embodiment of the present invention.

FIG. 3 shows an example of magnet arrangement in an arc evaporation source, where A is a cross-sectional view and B is a front view seen in the bb direction.

4A and 4B show another example of arrangement of magnets in an arc evaporation source, where A is a sectional view and B is a front view seen in the bb direction.

5A and 5B show still another example of magnet arrangement in the arc evaporation source, where A is a sectional view and B is a front view seen in the bb direction.

FIG. 6 is a diagram for explaining the behavior of an arc in an arc evaporation source in the case of a single magnetic field.

FIG. 7 is a diagram illustrating the behavior of an arc in an arc evaporation source in the case of a multi-pole magnetic field.

FIG. 8 is an enlarged view showing a part of the magnetic field in FIG.

9 is an enlarged view showing an example of the locus of the arc discharge position in FIG.

FIG. 10 is a front view showing another example of the gas blowing mechanism.

FIG. 11 is a schematic view showing an example of a conventional ion vapor deposition thin film forming apparatus.

[Explanation of symbols]

 2 Cathode 2a Cathode front surface 2b Cathode rear surface 4 Cathode material 14 Arc power supply 16 Vacuum container 20 Holder 22 Base material (processing object) 32 Gas spraying mechanism 34 Reactive gas 40 Arc type evaporation source 42, 46, 48 Permanent magnet 50 Electromagnet 80 ion source 84 ion

Claims (7)

[Claims] 1. A vacuum container, a holder provided in the vacuum container for holding a base material, an evaporation source for depositing an evaporation substance on the base material held by the holder, and a holder held by the holder. Equipped with an ion source for irradiating the substrate with ions,
An ion deposition thin film forming apparatus for forming a thin film on the surface of a substrate by using both vacuum deposition and ion irradiation, wherein the evaporation source uses an arc discharge at a cathode to evaporate a cathode substance, An ion vapor deposition thin film forming apparatus comprising an arc evaporation source having a gas blowing mechanism for blowing a reactive gas that reacts with constituent substances onto the front surface of a cathode. 2. The ion vapor deposition thin film forming apparatus according to claim 1, wherein a plurality of magnetic poles having different polarities are arranged in the vicinity of the rear of the rear surface of the cathode of the arc evaporation source so as to face the rear surface of the cathode. 3. A plurality of rod-shaped permanent magnets having different polarities are arranged by arranging one of the magnetic poles so that one magnetic pole faces the cathode rear surface and the N pole and the S pole are alternately arranged. The ion deposition thin film forming apparatus according to claim 2, wherein a plurality of magnetic poles are formed. 4. A plurality of rod-shaped permanent magnets are arranged so that one magnetic pole of each pole faces the rear surface of the cathode and the N pole and the S pole are randomly arranged so that the polarities differ from each other. The ion deposition thin film forming apparatus according to claim 2, wherein a plurality of magnetic poles are formed. 5. A plurality of rod-shaped permanent magnets, one magnetic pole of each of which faces the rear surface of the cathode, and those of the same polarity are arranged in a concentric ring shape, and an N pole group ring and an S pole are arranged in the inner and outer directions of the ring. The ion deposition thin film forming apparatus according to claim 2, wherein the plurality of magnetic poles having different polarities are formed by arranging the pole group rings so as to be alternately present. 6. One or more annular permanent magnets are concentrically arranged around a central permanent magnet, and one magnetic pole of each is opposed to the cathode rear surface, and an N pole is formed in the inner and outer directions of the ring. The ion deposition thin film forming apparatus according to claim 2, wherein the plurality of magnetic poles having different polarities are formed by arranging the S poles so as to be alternately present. 7. Three electromagnets are arranged such that one magnetic pole of each is opposed to the cathode rear surface and at every 120 degrees around a predetermined center, and three-phase alternating current is supplied to them. The ion deposition thin film forming apparatus according to claim 2, wherein the plurality of magnetic poles having different polarities are formed.