JP2011187837A - beta-IRON SILICIDE THIN FILM, METHOD OF MANUFACTURING THE SAME, AND DEVICE FOR MANUFACTURING THIN FILM - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a β-iron silicide thin film having light emission capability when excited, a method of manufacturing the same, and a device for manufacturing a thin film. <P>SOLUTION: When using a laser ablation method for irradiating a target 12 formed of iron silicide with a laser to attach scattered particles generated from the target 12 to a silicon substrate 10, the target 12 and the substrate 10 are arranged to be nearly parallel to each other, and rotated such that rotating axes (C<SB>10</SB>and C<SB>12</SB>(C<SB>12'</SB>)) of them are not superposed on each other, to change the laser irradiation part to the target 12, and this β-iron silicide thin film is formed on the substrate 10 while changing the position of the thin film formation part in forming the thin film. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a β-iron silicide thin film having a light emitting ability at the time of excitation, a method for producing the thin film, and an apparatus for producing the thin film.

Since silicon is abundant in raw materials (silicon compounds), it is widely known that it has high safety and environmental advantages such as high-purity and inexpensive products that are easily available and low in toxicity. Yes. Furthermore, it has a very excellent property as a semiconductor material and can be widely used, such as a crystal having a relatively large diameter, an appropriate band gap of 1.1 eV, and an epitaxial growth layer can be easily formed. .
However, from the viewpoint of a light emitting material that emits light upon excitation by light irradiation or the like, unfortunately, silicon is not suitable as a light emitting material because it is an indirect transition semiconductor. And most of the luminescent materials developed so far have the problem of lattice mismatch with silicon, are highly toxic, have scarce resources, and have significant safety and environmental issues. It is what has. For example, InGaAsP, which is an indium phosphide-based compound semiconductor used as a light source for optical fibers, As (arsenic) and P (phosphorus) are harmful to the human body, and supply of In (indium), Ga (gallium), etc. Has problems such as instability.
Therefore, development of a light emitting material made of a material having silicon as a constituent atom is strongly desired.

Promising examples of such light-emitting materials include various silicide semiconductors that exhibit various characteristics by bonding silicon atoms and metal atoms. Specifically, typical silicide semiconductors include chromium (Cr), manganese (Mn), iron (Fe), molybdenum (Mo), ruthenium (Ru), tungsten (W), rhenium (Re), osmium (Os). ), Transition metal silicides containing transition metals such as iridium (Ir), alkaline earth silicides containing alkaline earth metals such as magnesium (Mg), calcium (Ca), barium (Ba), etc. Is mentioned. The gap energy of these silicide semiconductors is widely distributed, for example, from 0.06 eV of FeSi to 2.3 eV of Os ₂ Si ₃ , and can be variously selected according to the purpose.

Among these, β-iron silicide (β-FeSi ₂ ) is the same as the magnesium silicide (Mg ₂ Si) and ruthenium silicide (Ru ₂ Si ₃ ), and the current communication wavelength matches the lowest loss wavelength of silica-based optical fibers. It has the above-mentioned properties of silicon, including a band gap in the vicinity, further capable of epitaxial growth on a silicon substrate, and a direct transition semiconductor having a forbidden band width of about 0.83 eV. In addition, since it is excellent in terms of safety and environment, it is extremely important in the field of optoelectronics.

On the other hand, β-iron silicide has not been sufficiently evaluated as a semiconductor because it is difficult to obtain at first. However, in 1985, it was reported that a polycrystalline β-iron silicide thin film was a direct transition semiconductor because of its light absorption characteristics (see Non-Patent Document 1). Furthermore, in 1997, infrared (˜1.5 mm) electroluminescence (EL) from a p-Si / β-FeSi ₂ microcrystal / n-Si structure was confirmed (see Non-Patent Document 2), and the semiconductor field. It has come to attract attention.

M.M. C. Bost and F.M. E. Mahan, J .; Appl. Phys. , 58, 2696 (1985) D. Leon, M.M. Harry, K.M. J. et al. Resson and K.M. P. Homewood, Nature, Vol. 387, 12, June, 686 (1997)

  However, although attempts have been made to obtain a β-iron silicide thin film having a light-emitting ability at the time of excitation, a practical manufacturing method has not been disclosed so far, so that it is practical as a material for optical elements. In fact, the characteristics of β-iron silicide have not been sufficiently studied.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the beta-iron silicide thin film which has the light emission ability at the time of excitation, the manufacturing method of this thin film, and the manufacturing apparatus of a thin film.

To solve the above problem,
The present invention relates to a method for producing a β-iron silicide thin film using a laser ablation method in which a target made of iron silicide is irradiated with laser to cause scattered particles generated from the target to adhere to a silicon substrate. And the substrate is arranged so as to be substantially parallel, rotated so that these rotation axes do not overlap, while changing the laser irradiation site to the target, while changing the position of the thin film formation site during thin film formation, A method for producing a β-iron silicide thin film is provided, wherein a β-iron silicide thin film is formed on the substrate.
In the method for producing a β-iron silicide thin film of the present invention, the target is held by a target holder, and the target holder includes a main body portion and a holding portion for holding the target, and the main body portion and the holding portion are individually provided. It is preferable that the main body part and the holding part are individually rotated to increase the change of the laser irradiation site on the target.
In the method for producing a β-iron silicide thin film of the present invention, it is preferable that the formation surface of the β-iron silicide thin film is (111) in the substrate.
The present invention also provides a β-iron silicide thin film produced by the production method of the present invention.
The β-iron silicide thin film of the present invention preferably contains a β-iron silicide single crystal.
The present invention is also a thin film manufacturing apparatus using a laser ablation method in which a target is irradiated with a laser and scattered particles generated from the target are attached to the substrate so that the target and the substrate are substantially parallel to each other. The thin film manufacturing apparatus includes at least a target holding unit and a substrate holding unit that are disposed in the substrate and rotatably hold so that the rotation shafts do not overlap with each other.
The present invention also provides a β-iron silicide thin film formed on a silicon substrate and containing a β-iron silicide single crystal.

  ADVANTAGE OF THE INVENTION According to this invention, the beta-iron silicide thin film which has the light emission ability at the time of excitation, the manufacturing method of this thin film, and the manufacturing apparatus of a thin film can be provided.

It is a diagram for explaining a manufacturing apparatus for manufacturing process a thin film of beta-FeSi ₂ thin film of the present invention. It is the imaging data of the thin film surface by SEM in Example 1, (a) Before annealing, (b) It is imaging data 20 hours after the start of annealing. It is a graph which shows the measurement data of the XRD pattern of the thin film in Example 1, and is a graph which shows the measurement data before annealing, and 5, 10, and 20 hours after an annealing start. It is a graph which shows the relationship between the wavelength of the light of the thin film in Example 1, and the transmittance | permeability, and is a graph which shows the relationship before annealing, and 5, 10 and 20 hours after an annealing start. It is a graph which shows the emission spectrum of the thin film in Example 1, and is a graph which shows the emission spectrum before annealing, and 1, 5, 8, and 20 hours after an annealing start. It is the imaging data of the thin film cross section by TEM in Example 1, (a) 5 hours after the start of annealing, (b) The imaging data after 20 hours. It is a graph which shows the emission spectrum of the thin film in Example 1, and is a graph which shows the emission spectrum for every measurement temperature 20 hours after the annealing start. It is a graph which shows the emission spectrum of the thin film in Example 1, and is a graph which shows the emission spectrum for every average excitation power 20 hours after the start of annealing. 4 is enlarged image data of the single crystal portion in FIG. 4, (a) enlarged image data after 5 hours and (b) 20 hours after the start of annealing. It is a graph which shows the relationship between the peak energy (Ep, unit: eV) of the emission spectrum of the thin film in Example 1 and Reference Example 1, and excitation power density, and the graph which shows the relationship 20 hours after the start of annealing. It is. It is a graph which shows the relationship between the temperature at the time of the excitation of the thin film in Example 1 and Reference Example 1, and the peak energy (Ep, unit: eV) of A-band, and is a graph which shows the relationship 20 hours after the start of annealing. . It is a graph which shows the emission spectrum of the thin film in the reference example 1 and Example 1, and is a graph which shows the emission spectrum for every measurement temperature 20 hours after the annealing start. It is a graph which shows the measurement result of the surface roughness (Ra) of the thin film by AFM in Examples 2-5 and Reference Examples 2-5. It is a graph which shows the measurement data of the XRD pattern of the thin film in Examples 2-5, and is a graph which shows the measurement data 20 hours after an annealing start. It is a graph which shows the measurement data of the XRD pattern of the thin film in the reference examples 2-5, and is a graph which shows the measurement data 20 hours after an annealing start.

<Β-Iron Silicide Thin Film Manufacturing Method and Thin Film Manufacturing Apparatus>
In the method for producing a β-iron silicide (hereinafter sometimes referred to as β-FeSi ₂ ) thin film according to the present invention, a target made of iron silicide (hereinafter sometimes abbreviated as FeSi ₂ target) is irradiated with a laser. A method for producing a β-FeSi ₂ thin film using a laser ablation method in which scattered particles generated from the target are attached to a silicon substrate (hereinafter sometimes abbreviated as Si substrate), the target and the substrate Are arranged so as to be substantially parallel to each other, are rotated so that their rotation axes do not overlap, change the laser irradiation site to the target, and change the position of the thin film formation site when forming the thin film, A β-FeSi ₂ thin film is formed thereon.
The thin film manufacturing apparatus of the present invention is a thin film manufacturing apparatus that uses a laser ablation method in which a target is irradiated with a laser and scattered particles generated from the target are attached to the substrate. It is characterized by comprising at least target holding means and substrate holding means which are arranged so as to be substantially parallel and are rotatably held so that their rotation axes do not overlap. The thin film production apparatus of the present invention is particularly suitable for application to the above-described method for producing a β-FeSi ₂ thin film of the present invention.
The β-FeSi ₂ thin film production method and thin film production apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1A is a view for explaining a β-FeSi ₂ thin film manufacturing method and a thin film manufacturing apparatus according to the present invention, in which a Si substrate and a FeSi ₂ target are disposed in the manufacturing apparatus when the thin film is formed. It is the schematic which shows a state. FIG. 1 shows an outline of the configuration, and in the present invention, the dimensional ratios and shapes of the respective components are not necessarily limited to those shown here.

  The manufacturing apparatus 1 shows only main parts here, and includes a vacuum chamber 11, a target holder 13 for holding a target, a substrate holder 14 for holding a substrate on which a thin film is formed, and a laser irradiation unit 15. And comprising.

  The laser irradiation unit 15 performs laser irradiation on the target held by the target holder 13 and is preferably capable of adjusting the laser irradiation angle θ to the target.

  The vacuum chamber 11 has a target and a substrate arranged in the internal space 110. A decompression means (not shown) is connected to the vacuum chamber 11, and the interior space 110 can be maintained in a high vacuum state by operating the decompression means. Further, a separate gas supply means (not shown) is connected to the vacuum chamber 11. For example, by supplying a desired type and amount of gas to the internal space 110 in a high vacuum state, Can be filled with gas.

The target holder 13 includes a holding portion 13a, a shaft portion 13b, and a backbone portion 13c, and these are configured so that the central axes coincide with each other.
The holding portion 13a has a plate shape such as a substantially disk shape, and is fixed to and integrated with the shaft portion 13b. The shaft portion 13b is rotatable with its central axis as the rotation axis C ₁₂ in Y ₁ direction, further, is a retractable to its central axis and substantially the same X ₁ direction, and holding the core unit 13c Has been. Accordingly, the holding portion 13a is also rotatable Y in _one direction about the axis of rotation C _12, and is capable of advancing and retreating in X ₁ direction. The shaft portion 13b and the backbone portion 13c are provided so that the airtightness of the vacuum chamber 11 can be maintained.
The material of the target holder 13 is the same as that of the target holder used in a normal laser ablation apparatus.

The substrate holder 14 also has the same configuration as the target holder 13. That is, the substrate holder 14 includes a holding portion 14a, a shaft portion 14b, and a trunk portion 14c, and these are configured so that the central axes thereof coincide.
The holding portion 14a has a plate shape such as a substantially disk shape, and is fixed to and integrated with the shaft portion 14b. The shaft portion 14b is rotatable in Y ₂ direction the central axis as the rotation axis C _10, further configured to be moved in the central axis direction substantially the same X ₂ direction, and holding the core unit 14c Has been. Accordingly, the holding portion 14a is also rotatable about an axis of rotation C ₁₀ in the Y ₂ direction, and is capable of advancing and retreating in the direction X _2. Here, it is preferable X ₂ direction is substantially the same as the X ₁ direction. The shaft portion 14b and the backbone portion 14c are provided so that the airtightness of the vacuum chamber 11 can be maintained.
The material of the substrate holder 14 is the same as that of the substrate holder used in a normal laser ablation apparatus.

The FeSi ₂ target 12 is held in the holding portion 13a of the target holder 13 and the Si substrate 10 is held in the holding portion 14a of the substrate holder 14 in the same manner as in a normal laser ablation apparatus.
Accordingly, at least one of the holding portion 13a and the holding portion 14a, the _{X 1} by moving direction and / or _X in _two directions, FeSi ₂ target 12 and the Si substrate 10 opposing between the surface of the distance L of the desired The value can be adjusted.
Further, the holding portion 13a is rotated in the _{Y 1} direction, FeSi ₂ target 12 is also rotatable about the axis of rotation _{C 12} intersecting the surface almost perpendicular. Similarly, by rotating the holding portion 14a in the Y ₂ direction, also Si substrate 10 is rotatable about the axis of rotation C ₁₀ intersecting the surface almost perpendicular.
Hereinafter, in this specification, the rotation of the FeSi ₂ target 12 and the Si substrate 10 refers to rotation around the rotation axis C ₁₂ and rotation around the rotation axis C ₁₀ unless otherwise specified. And

In the manufacturing apparatus 1, the rotation axis _{C 10} of the rotating shaft _{C 12} and the Si substrate 10 of the FeSi ₂ target 12, is characterized in that they do not overlap each other. By configuring in this way, for example, when the held FeSi ₂ target 12 and the Si substrate 10 are rotated in the same direction or in the opposite direction, the rotation axis C ₁₂ on the FeSi ₂ target 12 is not overlapped. and site, the specific site not overlapping with the rotating shaft C ₁₀ on the Si substrate 10, even if the rotational speed is matched, a change in relative positional relation therebetween. Even when only one of the FeSi ₂ target 12 and the Si substrate 10 is rotated, the relative positional relationship changes. In this way, by irradiating the laser with the positional relationship changed, a β-FeSi ₂ thin film having sufficient light emission ability can be manufactured as described later.

The rotation axis _{C 10} of the rotating shaft _{C 12} and the Si substrate 10 of the target 12 is preferably substantially parallel. Furthermore, in order to obtain a uniform film thickness, the distance S between the rotation axes and the distance L between the opposing surfaces of the FeSi ₂ target 12 and the Si substrate 10 are adjusted in consideration of the size of the substrate 10. It is preferable. For example, as will be described later, when the surface of the substrate 10 on which the thin film is formed has a substantially circular shape and the diameter thereof is 10 to 100 mm, or other than a substantially circular shape such as a polygonal shape, When the diameter of the inscribed circle is 10 to 100 mm, the distance S is preferably 10 to 35 mm, and more preferably 15 to 30 mm. The distance L is preferably 25 to 55 mm, and more preferably 35 to 45 mm. A β-FeSi ₂ thin film with higher luminous ability can be obtained by setting the lower limit value or more, and a β-FeSi ₂ thin film can be obtained more efficiently by setting the lower limit value or less.

In the target holder 13 shown here, for example, the case of arranging the one FeSi ₂ target 12 in the holding portion 13a, by rotating the holding part 13a to the shaft portion 13b integrally about the axis of rotation _{C 12,} FeSi ₂ target Although 12 can be rotated, the aspect of rotation is not limited to this. For example, in the target holder 13, the holding portion 13a may be separately rotatable independently of the shaft portion 13b. In this case, in addition to the shaft part 13b corresponding to the main body part, the holding part 13a can also be rotated, so that the rotation of the FeSi ₂ target 12 can be controlled more precisely. Furthermore, by rotating both the shaft portion 13b and the holding portion 13a, it is possible to further increase the change of the laser irradiation site on the FeSi ₂ target 12, and to form a uniform thin film efficiently. The holding portion 13a, if it is possible to rotate the FeSi ₂ target 12, to a whole may be adapted to rotate a portion may be adapted to rotate. And the mechanism in which the holding | maintenance part 13a rotates may be the same as that of the case of the axial part 13b.

Further, as a preferred target holder 13, the holding portion 13a, two or more of FeSi ₂ target 12 can be exemplified those which is capable of holding. In this case, the two or more FeSi ₂ targets 12 are preferably held at an equal distance on the holding portion 13a. For that purpose, for example, it is preferable to arrange a plurality of FeSi ₂ targets 12 having the same size at positions equidistant from the center of the surface of the holding portion 13a and at equal distances between adjacent targets. . Such a holding part of the target holder is illustrated in FIG. FIG. 1B shows an example in which six FeSi ₂ targets 12 are held. By using the target holder 13 ′ shown here and rotating it, a thin film can be manufactured while sequentially switching two or more FeSi ₂ targets 12. At this time, as described above, two or more FeSi ₂ targets 12 may be rotated together with the holding portion 13a ′ that is separately rotatable independently of the shaft portion 13b ′. Then, the rotation axis C _{12 ′} at that time may be prevented from overlapping with the rotation axis C ₁₀ of the Si substrate 10. The rotation axis C ₁₂₀ (corresponding to C ₁₂ in FIG. 1A) of the shaft portion 13b ′ is preferably substantially parallel to C _{12 ′} .

In FIG. 1 (a), the center axis of the holding part 13a, the shaft part 13b, and the backbone part 13c of the target holder 13 and the holding part 14a, the shaft part 14b, and the backbone part 14c of the substrate holder 14 are the same. an example is shown that is configured to, not limited to this in the present invention, the as the rotation axis C ₁₂ and the rotary shaft C ₁₀ do not overlap each other, and the target holder 13 and the substrate holder 14 It only has to be configured.
And in the range which does not prevent the effect of this invention, the manufacturing apparatus 1 can change, add or delete a part of structure suitably.

Manufacturing apparatus 1 includes a rotating shaft _{C 10} of the rotating shaft _{C 12} and the Si substrate 10 of the FeSi ₂ target 12, except that they do not overlap each other, may be similar to conventional laser ablation device. And the material, shape, size, etc. in each part of the manufacturing apparatus 1 should just be selected suitably according to the objective.

The β-FeSi ₂ thin film can be manufactured by the following method using the manufacturing apparatus 1.
First, the FeSi ₂ target 12 is held by the holding portion 13a of the target holder 13 and the Si substrate 10 is held by the holding portion 14a of the substrate holder 14, and the surfaces of the FeSi ₂ target 12 and the Si substrate 10 are substantially parallel. It arranges so that it may become.

Next, the FeSi ₂ target 12 is irradiated with a laser, and a thin film is formed on the surface of the Si substrate 10 by laser ablation. At the time of this laser irradiation, the FeSi ₂ target 12 is rotated around the rotation axis C ₁₂ to change the laser irradiation site on the FeSi ₂ target 12 and the Si substrate 10 is rotated around the rotation axis C _10. Then, the position of the thin film formation site during the thin film formation is changed. Here, “at the time of thin film formation” refers to a point in time when thin film formation on the substrate surface is progressing due to scattered particles generated from the target by laser irradiation to the target (hereinafter sometimes referred to as plume). . Therefore, the start time of laser irradiation and the start time of thin film formation do not necessarily coincide exactly, and the start time of thin film formation is after the start time of laser irradiation. Then, by rotating the Si substrate 10 when forming the thin film, the position of the portion of the surface of the Si substrate ₁₀ that does not overlap with the rotation axis C10 changes due to the rotation. Therefore, since the position of the site where the thin film is formed changes, it is assumed that the site where the plume reaches the surface of the Si substrate 10 changes.

The operation of rotating the FeSi ₂ target 12 may be performed at least one of before and at the time of laser irradiation. That is, it may be rotated only before laser irradiation, may be rotated both before and at the time of laser irradiation, or may be rotated only at the time of laser irradiation. In any method, the laser irradiation site on the FeSi ₂ target 12 can be changed sufficiently.
Further, the operation of rotating the Si substrate 10 may be performed at least one of before and during the formation of the thin film. That is, it may be rotated only before the thin film formation, may be rotated both before and at the time of thin film formation, or may be rotated only at the time of thin film formation. In any method, it is estimated that the plume arrival site on the surface of the Si substrate 10 can be sufficiently changed. Here, “thin film formation” refers to an operation of forming a thin film on the surface of the substrate by a laser ablation method, not only when forming a thin film on the surface of the Si substrate, but also on an already formed thin film. This includes the case of growing a thin film. Therefore, “before forming a thin film” does not necessarily mean a state where there is no thin film on the substrate surface.

The following (a)-(i) can be illustrated as a more specific aspect of a thin film formation process.
(A) The FeSi ₂ target 12 is rotated before laser irradiation, and the Si substrate 10 is rotated before thin film formation.
(B) The FeSi ₂ target 12 is rotated before the laser irradiation, and the Si substrate 10 is rotated when the thin film is formed.
(C) The FeSi ₂ target 12 is rotated before the laser irradiation, and the Si substrate 10 is rotated before and during the thin film formation.
(D) The FeSi ₂ target 12 is rotated during laser irradiation, and the Si substrate 10 is rotated before the thin film is formed.
(E) The FeSi ₂ target 12 is rotated during laser irradiation, and the Si substrate 10 is rotated during thin film formation.
(F) The FeSi ₂ target 12 is rotated during laser irradiation, and the Si substrate 10 is rotated before and during the formation of the thin film.
(G) The FeSi ₂ target 12 is rotated before and during laser irradiation, and the Si substrate 10 is rotated before thin film formation.
(H) The FeSi ₂ target 12 is rotated before and during laser irradiation, and the Si substrate 10 is rotated during thin film formation.
(I) The FeSi ₂ target 12 is rotated before and during laser irradiation, and the Si substrate 10 is rotated before and during thin film formation.

When the FeSi ₂ target 12 is rotated at the time of laser irradiation, the site of laser irradiation to the FeSi ₂ target 12 changes continuously. When the FeSi ₂ target 12 is rotated before the laser irradiation but not during the laser irradiation, the FeSi ₂ target 12 is irradiated with the laser, and then the FeSi ₂ target 12 is further rotated by a predetermined angle, and then FeSi ₂ By repeating a series of operations of “target rotation and laser irradiation” of irradiating the laser to the target 12 once or twice or more, the laser irradiation site to the FeSi ₂ target 12 is changed. The series of operations is preferably repeated twice or more.
The same applies to the case where the Si substrate 10 is rotated. When the Si substrate 10 is rotated at the time of thin film formation, the position of the thin film formation site continuously changes. When the Si substrate 10 is rotated before the thin film is formed, not at the time of forming the thin film, after the thin film is formed, the Si substrate 10 is further rotated by a predetermined angle, and then the thin film is formed. By repeating a series of operations of “thin film formation” once or twice or more, the position of the thin film formation site at the time of thin film formation changes. The series of operations is preferably repeated twice or more.

When the FeSi ₂ target 12 is rotated at the time of laser irradiation, it may be rotated for the entire time from the start to the end of laser irradiation, or may be temporarily rotated. Moreover, you may rotate continuously and you may rotate it intermittently by repeating rotation and a stop.
The rotation of the Si substrate 10 is the same. When the Si substrate 10 is rotated at the time of forming the thin film, it may be rotated for the entire time from the start to the end of the thin film formation or may be temporarily rotated. good. Moreover, you may rotate continuously and you may rotate it intermittently by repeating rotation and a stop.

Hereinafter, setting conditions and the like in the thin film forming process will be described in more detail.
As the FeSi ₂ target 12, for example, one prepared by a known method such as a sintering method or a melting method can be used.
The purity of the FeSi ₂ target 12 is preferably 99.9% or more, and more preferably 99.99% or more. By doing so, impurities in the β-FeSi ₂ thin film can be further reduced.
Further, the density of the FeSi ₂ target 12 is preferably 2 g / cm ³ or more, more preferably 5 g / cm ³ or more. The upper limit is not particularly limited as long as the effect of the present invention is not hindered. By doing in this way, the higher effect which suppresses the droplet adhesion at the time of thin film formation is acquired.
The size of the FeSi ₂ target 12 is not particularly limited, but when the surface shape on the laser irradiation side is substantially circular, the diameter is preferably 10 to 100 mm. Moreover, when the said surface shape is other than substantially circular shapes, such as polygonal shape, it is preferable that the diameter of the inscribed circle of the shape is 10-100 mm.
The number of FeSi ₂ targets 12 to be used while being held by the target holder 13 is not particularly limited, and may be one or two or more.

The Si substrate 10 preferably has a (111) formation surface of the β-FeSi ₂ thin film.
In addition, since an impurity layer such as an oxide film is easily formed on the substrate surface, the Si substrate 10 is preferably used after removing the impurity layer with hydrofluoric acid or the like.
The specific resistance of the Si substrate 10 is preferably 500 to 30000 Ω · cm, and more preferably 1000 to 20000 Ω · cm.
The size of the Si substrate 10 is not particularly limited, but the surface on the side on which the thin film is formed preferably has the same shape and size as the surface of the FeSi ₂ target 12 on the laser irradiation side.

  From the viewpoint of reducing the surface roughness (Ra) of the thin film, the temperature of the Si substrate 10 during the formation of the thin film is preferably 400 to 700 ° C, and more preferably 450 to 650 ° C. The surface roughness (Ra) of the thin film immediately after formation by the laser ablation method is preferably 0.1 to 25 nm, more preferably 0.1 to 20 nm. Further, the temperature of the Si substrate 10 during the formation of the thin film is preferably 500 to 700 ° C., more preferably 550 to 650 ° C. from the viewpoint of sufficiently forming a thin film having good crystallinity. .

The pressure in the internal space 110 of the vacuum chamber 11 is preferably 1 × 10 ⁻⁴ Pa or less, and more preferably 1 × 10 ⁻⁵ Pa or less.

The laser to be irradiated is not particularly limited, but an ArF excimer laser, a KrF excimer laser, or the like is preferable.
The frequency of the laser is preferably 5 to 20 Hz.
The irradiation energy of the laser irradiated from the laser irradiation unit 15 toward the FeSi ₂ target 12 is 1 to 10 J / cm ² when the laser irradiation unit 15 is narrowed down from the laser source (not shown) through the lens. preferable.

The laser irradiation angle θ to the FeSi ₂ target 12 is preferably 25 to 55 °, and more preferably 35 to 45 °. By doing in this way, a plume can be efficiently reached on the surface of Si substrate 10, and a thin film can be formed more efficiently.

  The laser may be irradiated continuously without stopping until thin film formation is completed, or may be irradiated intermittently by repeating irradiation and stopping. And in order to form a thin film more stably, it is preferable to irradiate continuously.

The laser irradiation time may be appropriately set in consideration of other irradiation conditions. For example, when the irradiation energy is in the above range, the total is preferably 30 to 120 minutes, and preferably 50 to 70 minutes. It is more preferable that Here, “total laser irradiation time” refers to the time required for irradiation when laser irradiation is continued without stopping before the thin film formation is completed. In this case, it indicates the total time required for the multiple irradiations.
When the laser is irradiated intermittently, the irradiation time for one time is not particularly limited, but is preferably 1 to 15 minutes, and more preferably 2 to 8 minutes.

At the time of laser irradiation or thin film formation, the rotation timing and time when the FeSi ₂ target 12 or the Si substrate 10 is temporarily or intermittently rotated, and the rotation angle by one rotation are appropriately determined according to the purpose. Just choose.
The rotation speed of the FeSi ₂ target 12 at the time of laser irradiation is preferably 25 to 75 rpm, and more preferably 40 to 60 rpm. Then, in the case of the holding portion 13a or 13a 'separately rotated, the rotational speed of the FeSi ₂ target 12 is preferably 25～60Rpm, more preferably 40～50Rpm. By doing so, a β-FeSi ₂ thin film with higher luminous ability can be obtained.
The rotational speed of the Si substrate 10 at the time of thin film formation may be the same as the rotational speed of the FeSi ₂ target 12.

  When the Si substrate 10 is rotated before the thin film is formed, it is preferable to adjust the rotation angle by one rotation so that the thin film formation site (plume arrival site) on the Si substrate changes greatly. In consideration of rotating a plurality of times with laser irradiation interposed therebetween, the rotation angle is preferably 60 to 120 °, and more preferably 80 to 100 °.

Laser irradiation site of FeSi ₂ target 12 is preferably to contain a portion not overlapping with the rotating shaft C _12, and more preferably contains no site overlapping the rotation axis C _12. By setting in this way, a uniform thin film can be obtained, and a β-FeSi ₂ thin film having higher luminous ability can be obtained.

In the present invention, the FeSi ₂ target 12 is preferably rotated at least at the time of laser irradiation, and at this time, it is preferable that the FeSi ₂ target 12 is continuously rotated at least in any time zone from the start to the end of laser irradiation. It is more preferable to rotate the entire time. In this way, it obtained stably the beta-FeSi ₂ thin film having excellent light emitting ability. Further, if the rotation is performed only at the time of laser irradiation, the thin film forming operation can be simplified.
In the present invention, it is preferable to further rotate the holding portion 13a or 13a ′.
In the present invention, it is preferable to irradiate the laser while rotating the Si substrate 10 and rotating the FeSi ₂ target 12.

In the present invention, after the thin film is formed as described above, it is preferable that the formed thin film is further annealed by heat treatment. By annealing, a β-FeSi ₂ thin film having further excellent crystallinity and luminous ability can be obtained.

In the case of annealing, for example, after the thin film is formed, the internal space 110 of the vacuum chamber 11 is cooled until the temperature of the internal space 110 becomes 15 to 50 ° C. while maintaining the decompressed state, An inert gas may be introduced, filled with this gas, and annealed at a predetermined temperature and time.
As the inert gas, nitrogen (N ₂ ) gas is preferable. The purity of the inert gas is preferably 99.99% or more.

The annealing temperature is preferably 950 ° C. or lower in consideration of production suitability and thin film quality. The annealing step preferably includes a high temperature step for maintaining a temperature of preferably 700 to 950 ° C, more preferably 850 to 950 ° C. By having a high temperature process, a β-FeSi ₂ thin film with better crystallinity can be obtained. And, by setting the temperature of the high temperature process to the lower limit value or more, it is possible to efficiently produce a β-FeSi ₂ thin film that is more excellent in luminous ability, and by setting the temperature to the upper limit value or less, a high-quality β-FeSi ₂ thin film can be quickly produced Can be manufactured.

  The annealing time may be appropriately adjusted according to the annealing temperature, but the time for the high temperature step is preferably 1 to 40 hours, more preferably 3 to 35 hours, and particularly preferably 10 to 30 hours. It is desirable to set.

The thickness of the β-FeSi ₂ thin film obtained in the present invention may be appropriately adjusted according to the application, and is not particularly limited. Further, the thickness of the β-FeSi ₂ thin film can be easily adjusted by adjusting the laser ablation conditions. At this time, for example, the thickness may be reduced by about 10 to 30% by annealing. Therefore, it is preferable to adjust the laser ablation conditions in consideration of this point.
For example, when applied to the field of optoelectronics, the thickness is preferably 40 to 120 nm, and more preferably 60 to 100 nm. The β-FeSi ₂ thin film having such a thickness is suitable for reducing the size of the device, and is further excellent in both light emission ability and crystallinity.

The production method of the present invention, as described below, beta-FeSi ₂ thin film containing single crystals of beta-FeSi ₂ is obtained. Such a thin film is extremely excellent in luminous ability upon excitation by light irradiation or the like. The present invention provides for the first time a β-FeSi ₂ thin film containing such a single crystal. Such a thin film is completely different from the conventional thin film in that the content of the single crystal is high. In addition, the present invention provides for the first time a method for stably producing such a β-FeSi ₂ thin film having excellent luminous ability. The production apparatus of the present invention is applicable to the production method of the present invention. Needless to say, the present invention can be applied to other than the production of the β-FeSi ₂ thin film.

The reason why the β-FeSi ₂ thin film produced according to the present invention is excellent in luminous ability as described above is not clear, but is presumed to be because, for example, the content of a single crystal is high.
The reason why the content of the single crystal is high is not clear, but, for example, in the initial stage of thin film formation, a single crystal is easily formed on or near the surface of the substrate, and the single crystal grows using this as a nucleus. It is presumed that it is easy.
Then, in the present invention, easy single crystal is formed, apt reason to grow, as described above, since the rotation axis of the rotary shaft and the Si substrate of FeSi ₂ target, do not overlap each other, on FeSi ₂ target The specific portion that does not overlap with the rotation axis (C ₁₂ ) and the specific portion that does not overlap with the rotation axis (C ₁₀ ) on the Si substrate are relative to each other even when the rotation speeds are the same. It is presumed that the positional relationship changes. In this way, the location of the plume generated from the FeSi ₂ target changes to the substrate surface by changing the positional relationship. In this way, it is presumed that the environment at the time of forming the thin film on the substrate surface becomes more uniform over the entire surface of the substrate by changing the arrival site of the plume, and the thin film is formed stably. Further, it is presumed that by rotating the FeSi ₂ target, the laser irradiation site changes, the plume is generated more stably, and the thin film is stably formed. It is presumed that such an action synergistically contributes to easy formation and growth of a single crystal on the substrate.

<Β-iron silicide thin film>
The β-FeSi ₂ thin film of the present invention is formed on a Si substrate and contains a single crystal of β-FeSi ₂ .
Such a β-FeSi ₂ thin film can be produced, for example, by the production method of the present invention.

The β-FeSi ₂ thin film of the present invention is extremely excellent in luminous ability upon excitation by light irradiation or the like. For example, it is excited by light irradiation and emits light in a wide temperature range such as 15 to 150K. The emission intensity at this time is generally higher as the temperature of the thin film is lower.

The β-FeSi ₂ thin film of the present invention has a direct transition type band structure and has a band gap of 0.83 to 0.87 eV, a high light absorption coefficient, and a high Seebeck coefficient. It is useful as a constituent material for solar cells, thermoelectric conversion elements and the like.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the following examples. In the following, “K” represents Kelvin.

[Example 1]
(Production of β-FeSi ₂ thin film)
A β-FeSi ₂ thin film was produced using the apparatus shown in FIG. However, what was shown in FIG.1 (b) was used as a target holder. The rotation axis (C _{12 ′} ) of the target and the rotation axis (C ₁₀ ) of the Si substrate were made substantially parallel, and the distance (S) between these rotation axes was 25 mm. The other details are as follows.
The FeSi ₂ target and the Si substrate were placed in the internal space of the vacuum chamber, and the pressure in the internal space was reduced to less than 1 × 10 ⁻⁵ Pa. As the FeSi ₂ target, one having a purity of 99.99%, a density of 3.0 g / cm ³ , a diameter of 20 mm, and a thickness of 3 mm was used. Then, a target holder 13 ′ having a holding portion 13a ′ having a diameter of 61 mm and having a concave portion for holding the target on the surface is used, and the FeSi ₂ target 12 is placed and held in the concave portion to form a circle. Six FeSi ₂ targets 12 were uniformly arranged. The Si substrate 10 has a specific resistance of 1000 to 20000 Ω · cm, a 10 mm × 10 mm square shape, and (111), which is washed with an organic solvent, and then hydrofluoric acid (HF: H ₂ O = 1: 20 (volume ratio)) was used for 1 minute to remove silicon oxide. A substrate holder 14 having a holding portion 14a having a diameter of 61 mm and having a concave portion for holding the Si substrate at the center of the surface was used, and the Si substrate 10 was placed and held in the concave portion. The distance (L) between the opposing target surface and the substrate surface was set to 40 mm.
Next, the temperature of the Si substrate is raised from room temperature to 600 ° C., and in this state, the Si substrate is not rotated, and the holding portion 13a ′ is rotated to rotate the FeSi ₂ target at a speed of 50 rpm. The target was irradiated with a 193 nm ArF excimer laser for 5 minutes, and a film forming operation was performed on the Si substrate. The laser frequency at this time was 10 Hz, and the irradiation energy was 4 J / cm ² . Further, the irradiation angle (θ) to the laser target was set to 40 °. Then, after stopping the laser irradiation, the Si substrate was rotated by 90 ° and stopped. The thin film was formed on the Si substrate by repeatedly performing the film forming operation from the laser irradiation at 600 ° C. to the rotation of the substrate until the total laser irradiation time was 1 hour.
Next, the internal space after the thin film formation is cooled to 50 ° C. or lower, and 99.9995% nitrogen gas is introduced and annealing is performed at 900 ° C. for 20 hours in the atmosphere of this gas. A target β-FeSi ₂ thin film was produced.

(Thin film analysis)
In the above manufacturing process, the following analyzes (1) to (6) were performed for each thin film immediately after the thin film was formed on the Si substrate (before annealing) and after a predetermined time from the start of annealing. These analyzes were performed while adjusting the temperature of a sample in which a thin film was formed on a Si substrate, using a helium flow cryostat.

(1) The thin film before annealing and 20 hours after the start of annealing was observed with a scanning electron microscope (SEM). The imaging data of the thin film surface at this time is shown in FIG. FIG. 2A shows the respective imaging data before annealing, and FIG. 2B shows the respective imaging data 20 hours after the start of annealing.
(2) The crystallinity of the thin film was analyzed before annealing and 5, 10, and 20 hours after the start of annealing by X-ray diffraction (XRD) after irradiation with Cu-Kα rays. The measurement data of the XRD pattern at this time is shown in FIG.
(3) The relationship between the wavelength of light and the transmittance in the thin film before annealing and after 5, 10 and 20 hours from the start of annealing was determined. The measurement data at this time is shown in FIG.
(4) While cooling the sample to 8K, the thin film before annealing and 1, 5, 8, and 20 hours after the start of annealing was irradiated with an Ar ion laser with a wavelength of 514.5 nm to excite β-FeSi ₂ The photoluminescence (photoluminescence) (PL) was measured. The emission spectrum at this time was analyzed using a single monochromator with a focal length of 32 cm and identified using an indium gallium arsenide (InGaAs) photodiode cooled with liquid nitrogen. The emission spectrum data of the thin film at this time is shown in FIG.
(5) The thin film was observed with a transmission electron microscope (TEM) at 5 and 20 hours after the start of annealing. The imaging data of the thin film cross section at this time is shown in FIG. 6A shows the respective imaging data after 5 hours from the start of annealing, and FIG. 6B shows the respective imaging data after 20 hours from the start of annealing.
(6) For a thin film 20 hours after the start of annealing, when the sample temperature was set to 15K and when the temperature was set to 10K from 20K to 150K, an Ar ion laser with a wavelength of 484 nm was used for the average excitation power. The β-FeSi ₂ thin film was irradiated to 100 mW to excite β-FeSi ₂ , and PL was measured. The analysis and identification of the emission spectrum were performed in the same manner as in the case of (4) above. The emission spectrum data of the thin film at this time is shown in FIG.
(7) For the thin film 20 hours after the start of annealing, the sample temperature was set to 15 K, and the average excitation power was set to be in the range of 0.05 to 100 mW, and an Ar ion laser with a wavelength of 484 nm was used. The β-FeSi ₂ thin film was irradiated to excite β-FeSi ₂ to measure PL. The analysis and identification of the emission spectrum were performed in the same manner as in the case of (4) above. The emission spectrum data of the thin film at this time is shown in FIG.

As shown in FIG. 2, in SEM, white spherical particles having a diameter of about 1 to 10 μm were observed on the surface of the thin film immediately after formation (see (a)), which were droplets. And by carrying out the annealing treatment (see (b)), these droplets did not change, but crystals grew and granular materials were observed, which seemed to increase the PL strength. These droplets were of a level that would not hinder the production of the β-FeSi ₂ thin film.
During laser irradiation, when the target is irradiated with a high-power laser pulse, if the absorbed pulse energy is localized near the surface of the target, the surface of the target whose temperature has risen instantaneously dissolves, but this dissolved target is scattered. And what adhered to the thin film surface is assumed to be observed as the above-mentioned droplets. It has been confirmed that such dissolution of the target and accompanying roughness of the target surface can be suppressed by increasing the density of the target, and can be suppressed almost completely by setting the target density to 6.0 g / cm ³ .

As shown in FIG. 3, in XRD, only the signal indicating (202) or (220) derived from the surface of the target β-FeSi ₂ thin film and the signal indicating (111) derived from the surface of the Si substrate are present. It was confirmed that the β-FeSi ₂ thin film was formed by epitaxial growth and contained a single crystal. This was confirmed by the imaging data of the thin film cross section by TEM shown in FIG. That is, as shown in FIG. 6A, the thin film after 5 hours from the start of annealing had a thickness of about 100 nm, and contained a single crystal in the thin film, particularly on the substrate side (lower side of the drawing). Further, as shown in FIG. 6B, the thin film 20 hours after the start of annealing had a thickness of about 80 nm, and contained a single crystal in the thin film, particularly on the substrate side (lower side of the drawing). The site indicated by the arrows in FIGS. 6A and 6B corresponds to a single crystal. The enlarged imaging data of these single crystal parts is separately shown in FIG. (A) of FIG. 9 is each enlarged imaging data 5 hours after the start of annealing and (b) is 20 hours after the start of annealing. In FIG. 9, the arrow indicates an observation site of an interference pattern (striped pattern) derived from a crystal structure having regularity in the thin film, and this pattern indicates that a single crystal of β-FeSi ₂ exists. It is thought that.
6A and 6B, a film made of silicon oxide (SiO _x ) is formed on the surface of the thin film, and this film functions to protect the surface of the thin film.

As shown in FIG. 4, it was confirmed that the light transmittance curve changes as the annealing time becomes longer immediately after the formation of the thin film. In FIG. 4, the peak near the wavelength of 1200 nm (1.033 eV) is derived from the Si substrate, and the peak near the wavelength of 1500 nm (0.827 eV) is derived from the β-FeSi ₂ thin film. In particular, in the wavelength range of 2000 to 2500 nm, the longer the annealing time, the higher the light transmittance.

As shown in FIG. 5, the peak (A-band) peculiar to β-FeSi ₂ in the vicinity of the photon energy of 0.808 eV increases as the annealing time increases, and the intensity increases particularly at 20 hours. It was remarkable. On the other hand, the peak around the photon energy of 1.1 eV is considered to be derived from the Si substrate and disappeared by annealing.

Here, the relationship between the excitation power density and the A-band peak energy (Ep, unit: eV) was further examined. The results are shown in FIG.
As shown in FIG. 10, the peak energy of the A-band was stable at about 0.808 eV when the excitation power density was within the range of 0.006 to 20 W / cm ² . This was in contrast to the fact that the peak energy of the D-band and B-band, which will be described later, greatly fluctuates depending on the excitation power density (not shown).

As shown in FIG. 7, in the PL emission spectrum, a high-intensity peak (A-band) peculiar to β-FeSi ₂ was observed in the vicinity of a photon energy of 0.808 eV. In addition, peaks are observed in the vicinity of 0.78 eV, 0.80 eV, and 0.85 eV (above, D-band), in the vicinity of 0.84 eV (B-band), and in the vicinity of 0.77 eV (DO ₂ -band). It was. The emission intensity was generally stronger as the measurement temperature was lower, and the peak intensity of the A-band was the highest at 15K and the lowest at 150K.

Here, the relationship between the temperature during excitation (15 K to 150 K) and the peak energy of the A-band (Ep, unit: eV) was determined for the thin film 20 hours after the start of annealing. The peak energy (Ep) was calculated using the Varshini equation represented by the following equation (1). The results are shown in FIG.
As shown in FIG. 11, the peak energy tended to decrease with increasing temperature, but the fluctuation range with respect to temperature change was small and stable.
Ep (T) = Ep (0) −αT ² / (β + T) (1)
Where T is the temperature (K); Ep (0) is the peak energy at 0K (0.8085 eV); α is the amount of energy change per 1K temperature (1.8 × 10 ⁻⁴ eV / K And β is a constant (300).)

  As shown in FIG. 8, the emission spectrum of PL is the same pattern as in FIG. 7, and when compared with the same photon energy, the emission intensity increases as the average excitation power decreases. The peak intensity was the largest at 100 mW.

[Reference Example 1]
A thin film is manufactured by performing a film forming operation on the Si substrate in the same manner as in Example 1 and performing an annealing process, except that an electrolytic iron (purity 99.99%) target is used instead of the FeSi ₂ target. did. And about the thin film 20 hours after the start of annealing, the temperature of the sample was set to 15K, and PL was measured by the method (6). The data of the emission spectrum of the thin film at this time is shown in FIG. 12 together with the data of Example 1.
Further, the relationship between the peak energy of the A-band and the excitation power density was examined by the same method as described above. The results are shown in FIG.
Further, the relationship between the temperature at the time of excitation (15 to 200 K) and the peak energy (Ep) of the A-band was determined by the same method as described above. The results are shown in FIG.

As shown in FIG. 12, the peak intensity of the A-band was clearly smaller than that in Example 1. That is, the light emission intensity of the thin film was lower than that in Example 1.
Further, as shown in FIG. 10, unlike the case of Example 1, the peak energy of the A-band greatly fluctuated depending on the excitation power density.
Further, as shown in FIG. 11, the peak energy showed a macroscopic tendency similar to that in the case of Example 1. However, microscopically, the peak energy fluctuated greatly even with a very small temperature change. The fluctuation range was wider than that in Example 1.

[Example 2]
The film formation operation was performed on the Si substrate in the same manner as in Example 1, and the surface roughness (Ra) of the thin film immediately after the thin film formation (before annealing) was measured with an atomic force microscope (AFM). did. The measurement data at this time is shown in FIG.
Next, the target β-FeSi ₂ thin film was produced by annealing in the same manner as in Example 1, and the thin film 20 hours after the start of annealing was crystallized by XRD in the same manner as in (2) above. Sex was analyzed. The measurement data of the XRD pattern at this time is shown in FIG. In FIG. 14, “Tg” indicates “Film Temperature”.

[Examples 3 to 5]
Except that the temperature of the Si substrate during the film formation operation (film formation temperature) was not 600 ° C. but 550 ° C. (Example 3), 500 ° C. (Example 4), and 450 ° C. (Example 5), respectively. A film forming operation was performed on the Si substrate in the same manner as in Example 1, and the surface roughness (Ra) of the thin film immediately after the thin film formation (before annealing) was measured by AFM. The measurement data at this time is shown in FIG.
Next, the target β-FeSi ₂ thin film was produced by annealing in the same manner as in Example 1, and the thin film 20 hours after the start of annealing was crystallized by XRD in the same manner as in (2) above. Sex was analyzed. The measurement data of the XRD pattern at this time is shown in FIG.

[Reference Example 2]
Except for using an electrolytic iron (purity 99.99%) target instead of the FeSi ₂ target, a film forming operation was performed on the Si substrate in the same manner as in Example 2, and the thin film immediately after the thin film formation (before annealing) The surface roughness (Ra) was measured by AFM. The measurement data at this time is shown in FIG.
Subsequently, the target β-FeSi ₂ thin film was manufactured by annealing in the same manner as in Example 2, and the crystallinity of the thin film 20 hours after the start of annealing was analyzed by XRD. The measurement data of the XRD pattern at this time is shown in FIG. In FIG. 15, “Tg” indicates “Film Temperature”.

[Reference Examples 3 to 5]
The temperature of the Si substrate during the film forming operation (film forming temperature) is not 600 ° C. but 550 ° C. (Reference Example 2), 500 ° C. (Reference Example 3), and 450 ° C. (Reference Example 4). A film forming operation was performed on the Si substrate in the same manner as in Reference Example 2, and the surface roughness (Ra) of the thin film immediately after forming the thin film (before annealing) was measured by AFM. The measurement data at this time is shown in FIG.
Next, a thin film was manufactured by annealing in the same manner as in Reference Example 2, and the crystallinity of the thin film 20 hours after the start of annealing was analyzed by XRD in the same manner as in (2) above. The measurement data of the XRD pattern at this time is shown in FIG.

As is clear from the results of Examples 2 to 5 shown in FIG. 13, the Ra of the thin film tended to increase as the film formation temperature increased, but the degree was mild, and the value of Ra itself Was also small. That is, the β-FeSi ₂ thin film of the present invention was smooth with few surface irregularities even in the laser ablation method even when the substrate temperature was in a wide range.
In contrast, in Reference Examples 2 to 5, the Ra of the thin film tended to increase as the film formation temperature increased, but the tendency was more prominent than in Examples 2 to 5, and , Ra itself was also large.

Further, as shown in FIG. 14, the β-FeSi ₂ thin films of Examples 2 to 5 have a signal indicating approximately (202) or (220) as a surface and a signal indicating (111) derived from the surface of the Si substrate. Since it can be confirmed that only single crystals are contained.
On the other hand, as shown in FIG. 15, the thin films of Reference Examples 2 to 5, particularly Reference Example 2, are formed on β-FeSi ₂ such as a signal indicating (040) or (004) or (422) as a surface. A large number of derived diffraction peaks could be confirmed, indicating a polycrystalline state.

  The present invention can be used in the entire field of optoelectronics, and is particularly useful as a constituent material for light emitting / receiving elements, solar cells, thermoelectric conversion elements, and the like.

DESCRIPTION OF SYMBOLS 1 ... Thin film manufacturing apparatus, 10 ... Silicon substrate, 12 ... Iron silicide target, 13, 13 '... Target holder, 13a, 13a' ... Target holder holding part, 13b, 13b '... Target holder shaft, 13c ... Target holder backbone, 14 ... Substrate holder, 14a ... Substrate holder holding portion, 14b ... Substrate holder shaft, 14c ... backbone portion of the-substrate _{holder, C 10} · · · rotation axis of the silicon _{substrate, C 12,} C 12 _'··· rotation shaft of iron silicide target

Claims (7)

A method for producing a β-iron silicide thin film using a laser ablation method in which a target made of iron silicide is irradiated with laser to adhere scattered particles generated from the target to a silicon substrate,
The target and the substrate are arranged so as to be substantially parallel, rotated so that their rotation axes do not overlap, the laser irradiation site to the target is changed, and the position of the thin film formation site is changed during thin film formation. On the other hand, a β-iron silicide thin film is produced by forming a β-iron silicide thin film on the substrate.   The target is held by a target holder, and the target holder includes a main body portion and a holding portion that holds the target, and the main body portion and the holding portion are individually rotatable. The method of manufacturing a β-iron silicide thin film according to claim 1, wherein the change of the laser irradiation portion to the target is increased by rotating each of the targets individually.   3. The method for producing a β-iron silicide thin film according to claim 1, wherein the formation surface of the β-iron silicide thin film is (111) in the substrate.   A β-iron silicide thin film manufactured by the manufacturing method according to claim 1.   The β-iron silicide thin film according to claim 4, comprising a single crystal of β-iron silicide. A thin film manufacturing apparatus using a laser ablation method in which a target is irradiated with a laser and scattered particles generated from the target are attached to a substrate.
An apparatus for producing a thin film, comprising at least a target holding means and a substrate holding means for arranging the target and the substrate so as to be substantially parallel and rotatably holding the rotation axes so as not to overlap.   A β-iron silicide thin film formed on a silicon substrate and containing a single crystal of β-iron silicide.