JP2721595B2 - Manufacturing method of polycrystalline thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a polycrystalline thin film having a uniform crystal orientation.

[0002]

2. Description of the Related Art Oxide superconductors discovered in recent years are excellent superconductors having a critical temperature exceeding the temperature of liquid nitrogen. At present, this type of oxide superconductor is a practical superconductor. There are various problems to be solved in order to use this. One of the problems is that the critical current density of the oxide superconductor is low.

[0003] The problem that the critical current density of the oxide superconductor is low is largely due to the existence of electrical anisotropy in the crystal itself of the oxide superconductor. It is known that electricity easily flows in the a-axis direction and the b-axis direction of the crystal axis, but hardly flows in the c-axis direction. From such a viewpoint, in order to form an oxide superconductor on a base material and use it as a superconductor, an oxide superconductor having a good crystal orientation is formed on the base material, and It is necessary to orient the a-axis or b-axis of the crystal of the oxide superconductor in the direction in which electricity is to flow, and to orient the c-axis of the oxide superconductor in the other direction.

Therefore, various means have heretofore been attempted to form an oxide superconducting layer having good crystal orientation on a substrate such as a substrate or a metal tape. As one of the methods, a single crystal base material such as MgO or SrTiO ₃ having a crystal structure similar to that of an oxide superconductor is used, and an oxide superconducting layer is formed on these single crystal base materials by a film forming method such as sputtering. A method has been implemented.

If a film forming method such as sputtering is performed using the single crystal base material of MgO or SrTiO ₃ , the crystal of the oxide superconducting layer grows on the basis of the crystal of the single crystal base material. It is possible to improve the orientation, and the oxide superconducting layer formed on these single-crystal substrates exhibits a sufficiently high critical current density of about several hundred thousand to several million A / cm ^2. It is known to

[0006]

In order to use an oxide superconductor as a conductor, it is necessary to form an oxide superconducting layer having good crystal orientation on a long base material such as a tape. is there. However, if an oxide superconducting layer is formed directly on a base material such as a metal tape, the metal tape itself is polycrystalline and its crystal structure is significantly different from that of the oxide superconductor. Layers cannot be formed at all. In addition, there is a problem in that the heat treatment performed when forming the oxide superconducting layer causes a diffusion reaction between the metal tape and the oxide superconducting layer, which breaks down the crystal structure of the oxide superconducting layer and deteriorates the superconducting characteristics.

Therefore, conventionally, on a base material such as a metal tape,
It has been practiced to cover an intermediate layer such as MgO or SrTiO ₃ and form an oxide superconducting layer on the intermediate layer. However, the oxide superconducting layer formed on this kind of intermediate layer has a critical current density (for example, several thousand to 10,000 A / c) which is considerably lower than that of the oxide superconducting layer formed on a single crystal substrate.
m ² ). this is,
It is considered that the reason is described below.

FIG. 16 shows a sectional structure of an oxide superconducting conductor in which an intermediate layer 2 is formed on a base material 1 such as a metal tape and an oxide superconducting layer 3 is formed on the intermediate layer 2. Here, in the structure shown in FIG. 16, oxide superconducting layer 3 is in a polycrystalline state, and a number of crystal grains 4 are randomly coupled. Looking at each of these crystal grains 4 individually, the c-axis of the crystal of each crystal grain 4 is oriented perpendicular to the substrate surface, but the a-axis and b-axis are oriented in a random direction. It is thought that it is. When the directions of the a-axis and the b-axis become disordered for each crystal grain of the oxide superconducting layer in this way, the quantum coupling of the superconducting state is lost at the crystal grain boundaries in which the crystal orientation is disordered. It is thought to cause a decrease in critical current density. The oxide superconductor is in a polycrystalline state in which the a-axis and b-axis are not oriented because the intermediate layer 2 formed thereunder has an a-axis and a b-axis.
This is probably because the oxide superconducting layer 3 grows so as to match the crystal of the intermediate layer 2 when the oxide superconducting layer 3 is formed because the polycrystalline state is not in the axial orientation.

By the way, other than the application field of the oxide superconductor, techniques for forming various alignment films on a polycrystalline base material are used. For example, in the field of optical thin films, the field of magneto-optical disks, the field of wiring boards, the fields of high-frequency waveguides, high-frequency filters, and cavity resonators. The problem is to form a good polycrystalline thin film. That is, if the crystal orientation of the polycrystalline thin film is good, the quality of the optical thin film, the magnetic thin film, the wiring thin film, etc. formed thereon is improved, and the crystal orientation is further improved on the base material. It is even more preferable if a good optical thin film, magnetic thin film, thin film for wiring, etc. can be directly formed.

As a core material of a magnetic head used in a high frequency band, a magnetic thin film such as permalloy or sendust which has high magnetic permeability and is thermally stable has been put to practical use. Conventionally, these magnetic thin films are formed on a predetermined substrate by vapor deposition or sputtering. However, if these magnetic thin films have low crystal orientation, it is difficult to control the magnetic anisotropy of the magnetic thin film. And the orientation of the crystal grains becomes disordered in the film plane, and there is a problem that the high frequency characteristics of the magnetic permeability are impaired. In addition, when the axial direction of the crystal axis in the film plane is disordered, local fluctuation called skew or ripple occurs in the in-plane magnetization, and the high-frequency characteristic of the magnetic permeability is impaired as described above. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a crystal axis c perpendicular to a film-forming surface of a substrate.
The axes can be oriented, and at the same time, the a-axis and the b-axis of the crystal axes of the polycrystalline thin film can be aligned along a plane parallel to the film forming surface, forming a polycrystalline thin film with excellent crystal orientation. The aim is to provide a method that can do this.

[0012]

According to the first aspect of the present invention, in order to solve the above problems, constituent particles of a target are beaten out by sputtering and deposited on a substrate to form a polycrystalline thin film on the substrate. a method of, when depositing the constituent particles on a substrate, hammered from target group
In addition to the constituent particles to be deposited on the film forming surface on the material, the constituent particles are deposited while irradiating ions generated by the ion source to the film forming surface of the base material from an oblique direction , and
As targets, yttrium-stabilized zirconia, Mg
O or SrTiO ₃ is used .

According to a second aspect of the present invention, in order to solve the above-mentioned problem, the irradiation angle when irradiating the substrate with the ion according to the first aspect is 40 to 60 degrees with respect to the film forming surface of the substrate. In the range.

According to a third aspect of the present invention, there is provided a reaction gas containing at least one of an inert gas ion and an inert gas and a constituent element of a polycrystalline thin film. A method for producing a polycrystalline thin film, characterized by using mixed ions of the following.

[0015]

When the constituent particles struck out of the target by sputtering are deposited on the film-forming surface of the base material, ions are simultaneously irradiated from an oblique direction, so that the constituent particles are efficiently activated. In addition to the c-axis orientation, the a-axis orientation and the b-axis orientation are also improved with respect to the film formation surface. As a result, even in the case of a polycrystalline thin film in which a large number of crystal grain boundaries are formed, all of the a-axis orientation, the b-axis orientation, and the c-axis orientation of each crystal grain are improved, and the film quality is improved. A crystalline thin film is obtained.

In order to form such a polycrystalline thin film having good orientation, it is most preferable to set the ion irradiation angle to 45 degrees. Further, in order to activate the constituent particles,
Argon ions and oxygen ions are preferred.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an apparatus used when carrying out the method of the present invention. The apparatus of this example has a configuration in which an ion source for ion beam assist is provided in a sputtering apparatus.

The apparatus of the present embodiment comprises a substrate holder 11 for holding a substrate A, a plate-like target 12 which is disposed diagonally above the substrate holder 11 at a predetermined interval, An ion source 13 is disposed at an obliquely upper side at a predetermined interval, and is disposed apart from the target 12, and a sputter beam irradiation device 14 disposed below the target 12 toward the lower surface of the target 12. It is configured. Also, reference numeral 1 in the figure
Reference numeral 5 denotes a target holder holding the target 12.

The apparatus of the present embodiment is housed in a vacuum vessel (not shown) so that the periphery of the substrate A can be maintained in a vacuum atmosphere. Further, an atmosphere gas supply source such as a gas cylinder is connected to the vacuum vessel, and the inside of the vacuum vessel is kept in a low pressure state such as a vacuum, and an inert gas atmosphere containing argon gas or another inert gas atmosphere or oxygen. The atmosphere can be set.

The base material A has various shapes such as a plate material, a wire material, and a tape material. The base material A is made of a metal material or alloy such as silver, platinum, stainless steel, copper, etc. It is made of various ceramics. When a long metal tape (a tape made of Hastelloy or stainless steel) is used as the base material A, a feeding device and a winding device for the metal tape are provided inside the vacuum vessel, and the feeding device is continuously controlled from the feeding device. Base material A on material holder 11
It is preferable that the polycrystalline thin film can be continuously formed on the tape-shaped substrate by feeding the film and subsequently winding the film with a winding device.

The substrate holder 11 is provided with a heater inside, so that the substrate A positioned on the substrate holder 11 can be heated to a required temperature. The target 1
Numeral 2 is for forming a target polycrystalline thin film, and has the same composition or a similar composition as the target polycrystalline thin film. Specifically, as the target 12, zirconia (Y) stabilized with MgO or Y ₂ O ₃ (Y
SZ), MgO, SrTiO ₃ or the like is used, but is not limited thereto, and a target suitable for a polycrystalline thin film to be formed may be used.

The ion source 13 has a structure in which an evaporation source is housed in a container, and an extraction electrode is provided near the evaporation source. Then, a part of the atoms or molecules generated from the evaporation source is ionized, and the ionized particles are controlled by an electric field generated by an extraction electrode and irradiated as an ion beam. There are various methods for ionizing particles, such as a DC discharge method, a high-frequency excitation method, a filament method, and a cluster ion beam method. The filament type is a method in which a tungsten filament is energized and heated to generate thermoelectrons, which are collided with evaporated particles in a high vacuum to be ionized. In the cluster ion beam method, clusters of aggregated molecules coming out of vacuum from a nozzle provided at an opening of a crucible containing raw materials are bombarded with thermal electrons to be ionized and emitted. In this embodiment, the ion source 13 having the internal structure shown in FIG. 2 is used. The ion source 13 includes an extraction electrode 17, a filament 18, and an introduction tube 19 such as an Ar gas inside a cylindrical container 16, and can irradiate ions from a tip of the container 16 in a beam shape in parallel. Things.

As shown in FIG. 1, the ion source 13 is opposed so that its central axis S is inclined at an inclination angle θ with respect to the upper surface (film forming surface) of the substrate A. This inclination angle θ
Is preferably in the range of 40 to 60 degrees, and most preferably around 45 degrees. Therefore, the ion source 13 is arranged so as to be able to irradiate ions at an inclination angle θ with respect to the upper surface of the substrate A. The ions to be applied to the base material A by the ion source 13 may be ions of a rare gas such as He ⁺ , Ne ⁺ , Ar ⁺ , Xe ⁺ , Kr ⁺ , or mixed ions of these and oxygen.

The sputter beam irradiator 14 has the same structure as the ion source 13 and can irradiate the target 12 with ions to strike out constituent particles of the target 12. In the method of the present invention, since it is important that the constituent particles of the target 13 can be beaten out, it is configured such that the constituent particles of the target 12 can be beaten out by applying a voltage to the target 12 with a high-frequency coil or the like. The sputter beam irradiation device 14 may be omitted.

Next, using the apparatus having the above structure, Y
A method for forming a polycrystalline thin film of SZ will be described. In order to form a polycrystalline thin film on the substrate A, a YSZ target is used, and the inside of the container containing the substrate A is evacuated to a reduced pressure atmosphere. And the ion source 1
3 and the sputter beam irradiation device 14 are operated. When the target 12 is irradiated with ions from the sputtering beam irradiation device 14, constituent particles of the target 12 are beaten out and fly over the substrate A. Then, on the base material A, the target 1
At the same time as depositing the constituent particles beaten out from Step 2, the ion source 13 irradiates mixed ions of Ar ions and oxygen ions. The irradiation angle θ at the time of this ion irradiation is most preferably 45 degrees, and is preferably in the range of 40 to 60 degrees. If θ is 90 degrees, the c-axis of the polycrystalline thin film is oriented at right angles to the deposition surface of the substrate A, but the (111) plane stands on the deposition surface of the substrate A, which is not preferable. . When θ is 30 degrees, the polycrystalline thin film does not even have c-axis orientation. If the ion irradiation is performed at the above angle, the (100) plane of the crystal of the polycrystalline thin film stands.

By performing sputtering while performing ion irradiation at such an irradiation angle, the a-axis and the b-axis of the crystal axes of the YSZ polycrystalline thin film formed on the substrate A can be oriented. This seems to be due to the fact that the sputtered particles during the deposition are efficiently activated by ion irradiation at an appropriate angle.

FIG. 3 shows a substrate A on which a YSZ polycrystalline thin film B is deposited by the above-described method. Polycrystalline thin film B shown in FIG.
Has fine crystal grains 20 having a cubic crystal structure,
A large number of the crystal grains 20 are bonded and integrated via a crystal grain boundary, and the c-axis of the crystal axis of each crystal grain 20 is oriented at right angles to the upper surface (film formation surface) of the base material A, The axes a and b are oriented in the same direction and are in-plane oriented. The c-axis of each crystal grain 20 is oriented at right angles to the (upper surface) deposition surface of the substrate A. The a-axis (or b-axis) of the crystal grains 20 are joined and integrated with each other at an angle (grain boundary tilt angle K shown in FIG. 2) of 30 degrees or less.

After the YSZ polycrystalline thin film B is formed on the substrate A as described above, an oxide superconducting layer is formed on the polycrystalline thin film B. In order to form the oxide superconducting layer on the polycrystalline thin film B, sputtering is performed in an oxygen gas atmosphere or the like using a target having a composition similar to or the same as the target oxide superconductor to oxidize the polycrystalline thin film B. An object superconducting layer may be formed, or a laser vapor deposition method of irradiating the target with a laser beam to extract and vaporize constituent particles may be performed.

In the polycrystalline thin film B, the c-axis is oriented in a direction perpendicular to the film-forming surface of the substrate A, and the a-axis and the b-axis are aligned along a plane parallel to the film-forming surface. Since it has good orientation, the oxide superconducting layer laminated on the polycrystalline thin film B by sputtering or laser vapor deposition is deposited and grown to match the orientation of the polycrystalline thin film B.

Thus, the oxide superconducting layer formed on the polycrystalline thin film B becomes an oxide superconducting layer in a polycrystalline state. In each of the crystal grains of the oxide superconducting layer, a base material is used. The c-axis through which electricity does not easily flow is oriented in the thickness direction of A, and the a-axes or b-axes are oriented in the longitudinal direction of the base material A. Therefore, the obtained oxide superconducting layer has excellent quantum coupling properties at the crystal grain boundaries and has little deterioration in superconducting properties at the crystal grain boundaries, so that it is easy to conduct electricity in the longitudinal direction of the substrate A, and the critical current density is excellent. Things are obtained.

(Production Example) An apparatus having the structure shown in FIG. 1 was used, and the inside of the container accommodating this apparatus was evacuated to 3.0 × 10 ^-4 torr by a vacuum pump. Base material is width 1
Hastelloy C, 0mm, 0.5mm thick, 10cm long
276 tape was used. A target made of YSZ (stabilized zirconia) was used, and a sputtering voltage of 1000 was used.
V, sputtering current 100 mA, irradiation angle of the ion source beam is set to 45 degrees or 90 degrees, and the assist voltage of the ion source is set to 300 V, 500 V, and 700 V, respectively, and the current of the ion source is set to 15 to 50 mA, respectively. After setting, ion irradiation was performed simultaneously with sputtering on the substrate to form a film-like YSZ layer having a thickness of 0.3 μm.

Each of the obtained YSZ polycrystalline thin films has a C
An X-ray diffraction test was conducted by the θ-2θ method using uKα rays. FIGS. 5 to 7 are diagrams showing the diffraction intensity of the sample measured by appropriately changing the ion beam voltage and the ion beam current at an incident angle of 45 degrees of the ion source. From the results shown in FIGS. 5 to 7, peaks of the (200) plane or the (400) plane of YSZ are recognized, and the (100) plane of the YSZ polycrystalline thin film is oriented along a plane parallel to the substrate surface. It was found that the YSZ polycrystalline thin film was formed with its C-axis oriented vertically to the upper surface of the substrate.
From the comparison of the magnitudes of the peaks shown in FIGS. 5 to 7, the larger the beam current and the smaller the beam voltage, that is, the larger the amount of ion irradiation at a lower speed, the better the c of the polycrystalline thin film. It was found that the axial orientation could be improved.

FIGS. 8 to 10 show the incident angle 90 of the ion source.
FIG. 6 is a diagram showing the diffraction intensity of a sample measured by appropriately changing the ion beam voltage and the ion beam current in degrees. 8 to 1
From the result shown in FIG. 0, it was confirmed that the c-axis orientation was sufficient even when the incident angle of the ion source was 90 degrees.

Next, it was measured whether the a-axis or the b-axis of the YSZ polycrystalline thin film was oriented in the c-axis oriented sample as described above. For the measurement, see FIG.
As shown in the figure, the YSZ polycrystalline thin film formed on the base material A is irradiated with X-rays at an angle θ, and is positioned at an angle of 2θ with respect to the incident X-ray in a vertical plane including the incident X-ray. The X-ray counter 25 is installed, and the value of the horizontal angle φ with respect to the vertical plane including the incident X-ray is appropriately changed, that is, the substrate A is rotated by the rotation angle φ as shown by the arrow in FIG. The orientation of the a-axis or the b-axis of the polycrystalline thin film B was measured by measuring the obtained diffraction intensity. The results are shown in FIGS.

As shown in FIG. 12, in the case of a sample manufactured by setting the incident angle of the ion beam to 45 degrees, when φ is set to 90 degrees and 0 degrees, ie, every 90 degrees with respect to the rotation angle φ. The peak of the (311) plane of YSZ appears. This corresponds to the (011) peak of YSZ in the substrate plane, and it became clear that the a-axes or b-axes of the YSZ polycrystalline thin film are oriented. On the other hand, as shown in FIG.
In the case of the sample manufactured by setting the degree, no special peak was observed, and it was found that the directions of the a-axis and the b-axis were disordered.

From the above results, it was clarified that the polycrystalline thin film of the sample manufactured by the method of the present invention was oriented not only along the c-axis but also along the a-axis and b-axis. Therefore, it has been clarified that by performing the method of the present invention, a polycrystalline thin film such as YSZ having excellent orientation can be produced.

On the other hand, FIG. 14 shows the results of using the sample of the YSZ polycrystalline thin film used in FIG. 12 and examining the crystal orientation of each crystal grain of the polycrystalline layer of this sample. In this test, when performing X-ray diffraction by the method described above with reference to FIG. 11, the diffraction peak was measured when the angle of φ was set to a value of −10 degrees to 45 degrees in increments of 5 degrees. is there. FIG.
It is clear from the results shown in that the diffraction peak of the obtained YSZ polycrystalline thin film appears within a grain boundary inclination angle of 30 ° but disappears at 45 °. Therefore, it was found that the grain boundary inclination angle of the crystal grain of the obtained polycrystalline thin film was within 30 degrees, and it was revealed that the thin film had good orientation.

FIG. 15 shows another example of an apparatus suitable for use in carrying out the method of the present invention. In the apparatus of this example, the same components as those of the apparatus shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. The difference between the apparatus of this example and the apparatus shown in FIG.
2 is provided, three sputter beam irradiation devices 14 are provided, and the high frequency power supply 30 is connected to the base material A and the target 12.

In the apparatus of this example, three targets 1
The composite film can be formed on the substrate A by punching out different kinds of particles from 2, 12, and 12, respectively, so that a polycrystalline film having a more complicated composition can be manufactured. Also,
The target 12 can be sputtered by operating the high frequency power supply 30. When the method of the present invention is carried out using the apparatus of this example, a polycrystalline thin film having excellent orientation can be obtained as in the case of the apparatus shown in FIG.

When the method of the present invention is carried out using the apparatus having the structure shown in FIG. 1 or FIG. 15, an optical thin film having good orientation, a magnetic thin film of a magneto-optical disk having good orientation,
Any of a thin film for fine wiring for an integrated circuit having good orientation, a dielectric thin film used for a high-frequency waveguide, a high-frequency filter, a cavity resonator, or the like can be formed. That is,
If these thin films are formed on the polycrystalline thin film B having good crystal orientation by a film forming method such as sputtering, laser deposition, vacuum deposition, or CVD (chemical vapor deposition), good compatibility with the polycrystalline thin film B is obtained. , These thin films are deposited or grown, so that the orientation is improved.

By producing these thin films by the method of the present invention, a high-quality thin film having good orientation can be obtained. Therefore, an optical thin film has excellent optical characteristics, a magnetic thin film has excellent magnetic characteristics, and Migration does not occur in a thin film, and a thin film having good dielectric properties can be obtained in a dielectric thin film.

[0042]

As described above, according to the present invention, yttrium-stabilized zirconia, M
When depositing constituent particles struck from either the gO or SrTiO ₃ target on the film-forming surface of the substrate, the target
Component particles that are beaten out of the substrate and deposited on the film deposition surface on the substrate
In addition, since the ion beam is irradiated from an oblique direction, the constituent particles can be efficiently activated. As a result, in addition to the c-axis orientation, the a-axis orientation and the b-axis orientation can be applied to the film-forming surface of the substrate. Can also be improved. Therefore, by performing the method of the present invention, even a polycrystalline thin film formed with a large number of crystal grain boundaries,
A polycrystalline thin film having good a-axis orientation, b-axis orientation, and c-axis orientation for each crystal grain can be formed.

If the angle at which the ions are irradiated is set to 45 degrees and the ions to be irradiated are mixed ions of argon and oxygen, a polycrystalline thin film with the most suitable orientation can be obtained. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of an apparatus used when carrying out the method of the present invention.

FIG. 2 is a cross-sectional view showing an example of an ion source used for implementing the present invention.

FIG. 3 is an explanatory view showing a polycrystalline thin film obtained by carrying out the method of the present invention.

FIG. 4 is an enlarged plan view of the polycrystalline thin film shown in FIG.

FIG. 5 is a graph showing an X-ray diffraction result of a sample of the present invention manufactured at a beam voltage of 300V.

FIG. 6 is a graph showing an X-ray diffraction result of a sample of the present invention manufactured at a beam voltage of 500V.

FIG. 7 is a graph showing an X-ray diffraction result of a sample of the present invention manufactured at a beam voltage of 700V.

FIG. 8 is a graph showing an X-ray diffraction result of a comparative sample manufactured at a beam voltage of 300V.

FIG. 9 is a graph showing an X-ray diffraction result of a comparative sample manufactured at a beam voltage of 500V.

FIG. 10 is a graph showing an X-ray diffraction result of a comparative sample manufactured at a beam voltage of 700V.

FIG. 11 is a configuration diagram for explaining a test method performed for examining a-axis orientation.

FIG. 12 shows (311) of the polycrystalline thin film of the example of the present invention.
It is a graph which shows the diffraction peak of a surface.

FIG. 13 shows (31) in the polycrystalline thin film of the comparative example.
It is a graph which shows the diffraction peak of 1) plane.

FIG. 14 shows (311) of the polycrystalline thin film of the example of the present invention.
It is a graph which shows the result of having measured the diffraction peak of the surface for every rotation angle of 5 degrees.

FIG. 15 is a configuration diagram showing another example of an apparatus suitable for use in carrying out the method of the present invention.

FIG. 16 is a configuration diagram showing a polycrystalline thin film manufactured by a conventional method.

[Explanation of symbols]

A: substrate, B: polycrystalline thin film, θ: inclination angle, w: rotation angle, 11: substrate holder, 12 ...
・ Target, 13 ・ ・ ・ Ion source, 14 ・ ・ ・ Sputter beam irradiation device, 15 ・ ・ ・ Target holder,

Claims (3)

(57) [Claims] 1. A sputtering hammered out the constituent particles of the target are deposited on a substrate by a method of forming a polycrystalline thin film on a substrate, when depositing the constituent particles on a substrate, the target Beat out and deposit on substrate
In addition to the constituent particles deposited on the surface, the ions generated by the ion source are radiated from the oblique direction to the film-forming surface of the substrate.
While depositing the constituent particles , the target and
And yttrium-stabilized zirconia, MgO, SrT
A method for producing a polycrystalline thin film, comprising using any one of iO ₃ . 2. The irradiation angle when irradiating the substrate according to claim 1 with ions is set to 40 to 60 with respect to the film forming surface of the substrate.
A method for producing a polycrystalline thin film, wherein the degree is in the range of degrees. 3. The polycrystalline thin film according to claim 1, wherein the ion is an inert gas ion or a mixed ion of an inert gas and a reaction gas containing at least one of the constituent elements of the polycrystalline thin film. Manufacturing method.