JP2003306397A - Functional membrane, and process and apparatus for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly functional membrane through liquid phase epitaxy (LPE) wherein temperature characteristics of a membrane material comprising a metal or ceramic material are improved and a process and an apparatus for manufacturing the functional membrane wherein the membrane material showing excellent temperature characteristics can be easily and stably manufactured. <P>SOLUTION: The functional membrane having a component composition that varies in the thickness direction is obtained by sequentially changing a film-forming temperature, either by directly and serially changing the temperature of a solution contacting a substrate or by sequentially moving the substrate vertically in a solution having a temperature gradient wherein the temperature is lower at deeper parts in a furnace, to change the component composition of the growing membrane in its thickness direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a film made of a metal material or a porcelain material by liquid phase epitaxial growth, and a composition change film is obtained by changing the composition in the thickness direction of the film. The present invention relates to a functional film capable of remarkably expanding a temperature application range of characteristics, a manufacturing method thereof, and an apparatus thereof.

[0002]

2. Description of the Related Art Materials used for devices in microwave / millimeter wave / optical communication, electroluminescence, laser oscillation, photoelectric conversion, thermoelectric conversion, dielectrics, superconductivity, etc. include spinel magnetic cores, sulfide semiconductors, Phosphide semiconductors, selenide semiconductors, telluride semiconductors, intermetallic compound semiconductors, garnet-based ferrites, perovskite-based dielectric filters and capacitors, LT / LNs, magneplanbite-based ferrites, spinel-based ferrites, sphalerite Examples include ferrite and wurtzite ferrite.

The above-mentioned metal-based materials or porcelain-based materials are often used in the form of a film, and the substrate is immersed in a solution prepared by dissolving the film material as a solute in a solvent in which inorganic salts and oxides are melted. Then, the solute is grown on the surface of the substrate to form a film, and a metal-based or porcelain-based functional film is formed by a liquid phase epitaxial method (hereinafter referred to as LPE method).

In the LPE method, an LPE apparatus having a vertical furnace core tube structure in which a crucible is arranged in a cylindrical core is often used.
The solute melting temperature, that is, the temperature of the solution in the crucible is made uniform and constant, and a metal-based or porcelain-based functional film having uniform film-forming components and its properties is produced. . (See JP-A-5-229893, etc.)

[0005]

Even if the material is formed by the LPE method using a solution containing a solute having a desired composition for obtaining the required characteristics, if the temperature condition changes, for example, the above-mentioned material is generally used. The characteristics also change and it becomes impossible to secure the required characteristics. That is, the characteristics of the device will change greatly depending on the temperature of the environment in which it is used.

There is a limit to the temperature stabilization of the required characteristics of the film material, that is, the improvement of the temperature characteristics in the study of the component composition. Generally, the control of the crystal grain size, the control of the orientation direction, and the HIP are performed.
There have been various studies such as densification due to factors such as densification, and formation of a composite composite with a third material, but this has not been resolved.

Regarding the above-mentioned investigation of the component composition, there is an attempt to improve the temperature characteristics of the film material by producing a multilayer film composed of a plurality of films having different compositions. However, in order to laminate and bond a plurality of films, there are problems in the process such as handling of bonding boundaries, problems such as the limit of the number of films to be bonded, and it is necessary to prepare a solution having a plurality of compositions. It requires more labor, time and cost than the LPE method. Further, there is a problem that the lattice mismatch between the constituent films to be laminated causes the deterioration of the target characteristics and causes the peeling of the films.

An object of the present invention is to provide a highly functional film having improved temperature characteristics of a film material composed of a metal material or a porcelain material by liquid phase epitaxial growth, and to easily provide a film material excellent in such temperature characteristics. Moreover, it is an object of the present invention to provide a method for manufacturing a functional film and a device therefor capable of being stably manufactured.

[0009]

Means for Solving the Problems As a result of various studies on the constitution of the high-performance film having improved temperature characteristics, the inventors have found that the characteristics obtained in a certain composition are obtained by superimposing a plurality of compositions. The characteristics can also be superposed, that is, the temperature characteristics of the required characteristics of the film are stabilized by the superposition of a plurality of characteristics by superimposing (modulating) a plurality of compositions. In other words, it has been found that the temperature characteristic of the required characteristic is improved by obtaining the modulation film having the component composition.

Therefore, as a result of various studies on the manufacturing method for obtaining the component composition changing film in which the component composition is changed in the thickness direction of the film, the inventors tried to form a film on the substrate in the solution by the LPE method. It was found that the component composition can be changed in the thickness direction of the film to be grown by sequentially changing the solution temperature, that is, the film forming temperature.

Further, as a result of extensive studies on the method of changing the film forming temperature, the inventors changed the temperature of the solution or set a temperature gradient so that the temperature of the solution may be lowered or raised in the depth direction of the solution. The inventors have found that a modulation film having a component composition can be obtained by providing the substrate and sequentially moving the substrate up and down in this solution, and completed the present invention.

That is, the present invention is a film made of a metal material or a porcelain material by liquid phase epitaxial growth, and is a functional film characterized by having a component composition modulation in the thickness direction of the film.

The present invention is a method for forming a solute in a solution by liquid phase epitaxial growth on a substrate surface to form a film. The thickness of the grown film is changed by changing the film forming temperature when the solute is grown on the substrate surface. A method for forming a functional film is characterized in that the component composition is modulated in the direction.

According to the present invention, in the method of forming a functional film, the method of changing the film forming temperature is as follows: 1) changing the solution temperature, 2) setting a temperature gradient to the melting temperature in the solution in advance. Aside
A method of moving the substrate in the solution, 3) a method of controlling and holding the solution temperature in advance in the depth direction of the solution pool so that the temperature of the solution is lowered or raised, and sequentially raising and lowering the substrate in the solution are also proposed.

The present invention also provides the functional film or film forming method as described above, wherein 4) the temperature range of the solution temperature change is 100 ° C. or higher, 5) the solute is a metal material, and a sulfide semiconductor or phosphide is used. Semiconductor, selenide semiconductor, telluride semiconductor, intermetallic compound semiconductor, 6) Solute is porcelain material, Magneplumbite porcelain, spinel porcelain, garnet porcelain, perovskite porcelain, zinc zinc blend A structure that is either a mineral-based porcelain or a wurtzite-based porcelain, 7) Garnet-based porcelain has the general formula R1 _3-x R2 _x Fe
_5-y M y O ₁₂ (where R1 and R2 Y, Bi, Ca,
Pb, Sr, Ba, Cd, Cu, Mg, Mn, Cr, N
a and at least one of lanthanum-based transition elements, M
Is Al, Ga, In, Mn, Cr, Sc, Cu, Zn,
Mg, Ni, Co, Li, Ge, Si, V, P, As,
At least one of V, Sb, and Ti), and 0 ≦
A configuration satisfying x ≦ 3 and 0 ≦ y ≦ 5 is also proposed.

Further, the present invention is a liquid phase epitaxial growth apparatus having a vertical furnace core tube structure in which a crucible is arranged in the furnace, and a plurality of heating devices provided in the outer peripheral portion of the furnace as means for changing the film forming temperature. The manufacturing apparatus is provided with a heater, a gas nozzle that blows gas onto the solution surface of the crucible, and a cooler that cools the bottom of the crucible.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Liquid phase epitaxial method (LPE
Method) is a solution in which a film material of a metal material or a porcelain material is dissolved as a solute in a solvent in which an inorganic salt and an oxide are melted, and the substrate is immersed to grow a functional film on the upper surface of the substrate. This is a method for forming a film, and the composition amount of a certain constituent element A present in the grown film and the composition amount of A in the solution have a relationship expressed by the following distribution coefficient. Partition coefficient = A composition in film / A composition in solution

This distribution coefficient changes depending on the film forming conditions.
Furthermore, in the component system consisting of other plural constituent elements, the distribution coefficient for each element is different,
There are also various changes depending on the film forming conditions. That is, LP
The composition of the production phase existing in the film formed by the E method changes depending on the film forming conditions, particularly the film forming temperature.

According to the present invention, in the LPE method, in a solution consisting of a solvent and a solute of the same composition in a melting crucible, the composition of a metal-based material or a porcelain-based material film grown at different film forming temperatures is different, The inventors have found that the characteristics of the obtained film, for example, the lattice constant, magnetic characteristics, saturation magnetization, required characteristics such as ΔH, and these temperature characteristics are different, and utilize them effectively.

In the LPE method according to the present invention, the solute in the solution is grown on the surface of the substrate to change the film forming temperature at the time of forming a film so that the composition of the grown film is modulated in the thickness direction. Is the way. Specifically, as shown in FIG. 1A, a method of changing the temperature of the solution in contact with the substrate, or as shown in FIG. 1B, the solution temperature in the crucible is appropriately changed beforehand, that is, the solution temperature at a deep position is changed. 850 ° C,
In this method, the temperature of the solution closer to the surface is kept at 950 ° C. and the substrate is moved within the solution.

Explaining in detail below, the composition of the film to be grown changes depending on the film forming temperature, that is, the solution temperature at the time of growing the solute on the substrate surface. For example, the constituent elements A, B, C
In the case of the component system consisting of, the distribution coefficient of the composition of each of A, B, and C is different, and the change of the distribution coefficient depending on the film forming temperature is also various. As shown in FIG. Film composition is A ₂ B ₂ C ₂ and A _1.5 B at 900 ℃
_{At 1.5} C ₃ and 850 ° C., it changes to A ₁ B ₁ C ₄ . Therefore, the temperature of the solution in the crucible is changed from 950 ° C to 850 ° C.
When film formation is performed while adjusting the temperature to 0 ° C., a film in which these compositions are superposed or continuously modulated from A ₂ B ₂ C ₂ to A ₁ B ₁ C ₄ is formed.

Next, according to the method shown in FIG. 3, in a solution having a temperature gradient in the depth direction of the solution in the crucible, the solution temperature varies depending on the dipping position of the substrate, so that the phase of the film formed depends on the film forming position. And that changes in composition are effectively utilized.

More specifically, the temperature of the solution in the crucible has a temperature difference from 980 ° C. on the surface side to 730 ° C. on the bottom side and 250 ° C., that is, a temperature gradient in which the temperature decreases in the depth direction,
When the position of the substrate immersed in the solution is 850 ° C., the composition of the film formed is A ₁ B ₁ C ₄ , and at 900 ° C., A _1.5 B _1.5 C ₃ , 95
It changes to A ₂ B ₂ C _{2 at} 0 ° C. Therefore, the substrate is 850
By moving to a position where the solution temperature is different from ℃ to 950 ℃, the composition is superimposed or A ₁ B ₁ C ₄ to A ₂ B ₂ C ₂
A continuously modulated film is formed.

Further, by combining the method of changing the solution temperature and the method of moving the substrate by providing a temperature gradient in the depth direction to the solution temperature, the change range of the film forming temperature can be further increased in the same film forming time. It can be made wider. That is, in addition to the change in the overall solution temperature, the temperature change during film formation can be further increased by adjusting the film formation position as shown by the arrow in FIG. More specifically, the broken line arrow indicates the case where the position of the substrate is not changed, and the film formation temperature change is 900 ° C. to 800 ° C. The solid line arrow indicates the case where the position of the substrate is changed, and the film formation temperature change is 950 ° C. The change is larger from ℃ to 800 ℃.

By any of the above methods, the film grown on the substrate is a functional film whose component composition is modulated in the thickness direction, and the composition is superimposed in the thickness direction,
Therefore, the characteristics are superimposed, and the temperature stabilization improvement of the required characteristics can be realized. That is, the functional film formation according to the present invention can improve the magnetic properties, the saturation magnetization, the required properties such as ΔH, and the temperature properties thereof.

In the present invention, the method of holding the substrate at a fixed position to change the solution temperature and the method of moving the substrate by providing a temperature gradient in the depth direction to the solution temperature have been described.
Furthermore, by providing a temperature gradient in the solution in the depth direction from the solution surface and by concentrically providing a temperature gradient in the horizontal direction in the solution to move the substrate, both the in-plane direction and the thickness direction of the film can be obtained. It is possible to provide a film whose component composition is modulated, and also to obtain a film whose component composition is modulated by horizontally moving the substrate by providing a temperature gradient in a concentric circle in the horizontal direction in the solution. .

As the manufacturing apparatus used for the above-described LPE method according to the present invention, any known film forming apparatus can be used. An example using the apparatus of the vertical furnace core tube structure will be described based on FIG. Three heaters 2a, 2b, 2c are provided on the outer peripheral portion of the vertical cylindrical furnace core tube 1 made of alumina, and the furnace body 3 is surrounded by the heaters 2a, 2b, 2c.
Is provided.

A shutter 4 is arranged above the furnace body 3, and a crucible 6 for containing a solution 5 composed of a solute of a film made of a metal material or a porcelain material and a solvent is provided with a cooler for cooling the bottom surface thereof. It is supported by the supporting table 7 that it has.

The substrate 8 serving as a film-forming base is horizontally held by a substrate holder 9 and vertically held by a support rod 10. Further, the support rod 10 can rotate the substrate holder 9. Furthermore, above the crucible 6, a gas nozzle 11 for adjusting the temperature by spraying air, O ₂ , N ₂ , Ar, and He onto the liquid surface of the solution 5 is arranged.

In the film forming apparatus having the vertical furnace core tube structure having the above-mentioned structure, the heaters 2a, 2b and 2c, the cooler of the support base 7, and the gas nozzle 11 are made to cooperate with each other to perform a control operation of a required pattern. Then, as shown in the example, a temperature gradient of a temperature difference of 100 ° C. or more can be formed in the depth direction of the solution 5 with only about 20 to 30 mm. It is also possible to form a temperature gradient in concentric circles of the solution.

In the present invention, in order to improve the temperature characteristics of the functional film, it is desirable that the change range of the film formation temperature be as wide as possible to expand the modulation range of the component composition. The change range of is preferably 100 ° C. or higher, and may be 200 ° C. or higher.

In the present invention, the functional film is made of a metal material or a porcelain material. The metal material is preferably a sulfide semiconductor, a phosphide semiconductor, a selenide semiconductor, a telluride semiconductor, or an intermetallic compound semiconductor.

As the porcelain material, a magne plumbite porcelain, a spinel porcelain, a garnet porcelain, a perovskite porcelain, a zinc blende porcelain and a wurtzite porcelain are preferable.

In the present invention, the garnet-based porcelain material is represented by the general formula R1 _3-x R2 _x Fe _{5- y My} O ₁₂ (wherein R1 and R2 are Y, Bi, Ca, Pb, Sr,
At least one of Ba, Cd, Cu, Mg, Mn, Cr, Na and lanthanum-based transition elements, M is Al, G
a, In, Mn, Cr, Sc, Cu, Zn, Mg, N
i, Co, Li, Ge, Si, V, P, As, V, S
at least one of b and Ti), and 0 ≦ x ≦
A configuration satisfying 3, 0 ≦ y ≦ 5 is preferable.

[0035]

Example 1 A YPE was performed on a GGG substrate (111) surface having a diameter of 50 mm by an LPE method using a conventional film forming apparatus having a vertical furnace core tube structure.
_1.5 Gd _1.5 Fe _4.75 Al _0.25 O ₁₂ (hereinafter YGI
A film (referred to as AG) was formed. Three samples, a solution temperature of 950 ° C. (hereinafter referred to as sample 1), a solution temperature of 850 ° C. (hereinafter referred to as sample 2), and a sample (hereinafter referred to as sample 3) formed by changing the solution temperature during epitaxial growth, as shown in FIG. did.
FIG. 7 shows the result of measuring the Al element amount distribution in the obtained YGIAG film.

As is apparent from FIG. 7, the Al amounts of Sample 1 and Sample 2 do not change in the film thickness direction, but Al of Sample 3 is
There are portions where the amount is 3.8 mol% and 1.0 mol%, and the Al amount changes linearly between them. From this, it was confirmed that by changing the solution temperature during film formation, modulation of the component composition was obtained in the film thickness direction.

Next, FIG. 8 shows the results of measuring the saturation magnetization temperature characteristics of each YGIAG film when the applied magnetic field was 5 kGconst. As is clear from FIG. 8, Sample 2 has a maximum saturation magnetization of 950 G and a compensation temperature of −200 ° C.
Sample 1 has a maximum saturation magnetization of 250 G and a compensation temperature of -2.
The temperature is 0 ° C., and the change of the saturation magnetization with respect to the temperature change is large near room temperature in all the samples. However, Sample 3 shows a state in which the change in saturation magnetization with temperature is the sum of Sample 1 and Sample 2, and the change in saturation magnetization with respect to temperature change is small near room temperature.

The saturation magnetization temperature coefficient α (/ ° C.) of each YGIAG film is 10,000 × 10 ^{−6 for} sample 1 and 3000 × 10 ^{−6 for} sample 2, and α of −10 to 50 ° C. is 10 in both cases.
Although it is not less than 00 × 10 ⁻⁶ , Sample 3 shows a very small value of 180 × 10 ⁻⁶ . That is, a garnet film having a small saturation magnetization temperature coefficient could be obtained by the film forming method of the present invention.

The temperature range T _{l to} T _h (° C.) (T _l <
Α of T _h ) is given by the following equation. However, Δ (4
πMs): Amount of change in saturation magnetization from T _{1 to} T _h , (4πM
_{s) Ce} nter: (indicating the saturation magnetization at _{T h + T l) / 2} . α = Δ (4πMs) / ((4πMs) _Center × (T _h −
T _l ))

Example 2 GGG substrate (111) with a diameter of 50 mm by LPE method
On the surface, Y₁Gd₁Bi ₁  Fe_FiveO₁₂(Hereafter YGBIG
A film is formed. Solution temperature 950 ° C (hereinafter sample
4), solution temperature 850 ° C (hereinafter sample 5), and epitaxy
During the axial growth, the solution temperature as shown in FIG.
The three samples (hereinafter referred to as sample 6) formed by changing the film thickness
A film was formed.

FIG. 9 shows the result of measuring the distribution of the amount of constituent elements in each YGBIG film obtained. As shown in the figure, the Bi amounts of Samples 4 and 5 did not change in the film thickness direction,
In sample 6, the Bi amount is 12 mol% and 4.2 mol%, and the Bi amount changes linearly between them.
From this, it was confirmed that the component composition was modulated in the film thickness direction by changing the solution temperature during film formation.

Next, FIG. 10 shows the results of measuring the saturation magnetization temperature characteristics of each YGBIG film when the applied magnetic field was 5 kGconst. As is clear from the figure, sample 5 has a maximum saturation magnetization of 800 G and a compensation temperature of −150 ° C. or lower, and sample 4 has a maximum saturation magnetization of 700 G and a compensation temperature of −80 ° C. The change in saturation magnetization with respect to temperature change is large near room temperature. However, the temperature change of the saturation magnetization of the sample 6 shows a mode in which the sample 5 and the sample 6 are added, and the change of the saturation magnetization with respect to the temperature change is small near room temperature.

The saturation magnetization temperature coefficient α (/ ° C.) of each YGBIG film was 3200 × 10 ⁻⁶ for sample 4 and 1 for sample 5.
600 × 10 ^-6 and α of 100 at -10 to 50 ° C are 100
Although it is 0 × 10 ⁻⁶ or more, Sample 6 shows an extremely small value of 330 × 10 ⁻⁶ . That is, a garnet film having a small saturation magnetization temperature coefficient could be obtained by the film forming method of the present invention.

Example 3 The LPE method according to the present invention was carried out using the film forming apparatus of the vertical furnace core tube structure according to the present invention shown in FIG. Using PbO and B ₂ O ₃ as solvents in the crucible, Fe ₂ as a garnet film material
O ₃ , R1 ₂ O ₃ , A ₂ O ₃ , and R2 ₂ O ₃ are heated and melted to homogenize, and then the temperature between the liquidus line and the solidus line, that is, 800
A temperature distribution as shown in FIG. 1B was given in a supercooled state of up to 1000 ° C.

After that, a GGG substrate (11
On the 1) surface, a YGIAG film similar to that in Example 1 was formed. Solution temperature 980 ° C. (Sample 7 below), solution temperature 880
C. (hereinafter referred to as sample 8), and a sample (hereinafter referred to as sample 9) was formed by moving the substrate in a solution having a temperature distribution shown in FIG. 11A and changing the film forming position as shown in FIG. 11B. Filmed FIG. 12 shows the measurement result of the Al element amount distribution in the obtained YGIAG films.

As is apparent from FIG. 12, sample 7 and sample 8
The amount of Al does not change in the film thickness direction.
There are places where the amount of 1 is 4 mol% and 1.25 mol%, and the amount of Al changes linearly between them. From this, it was confirmed that the component composition was modulated in the film thickness direction by providing the temperature gradient in the depth direction of the solution temperature and moving the substrate to change the film formation temperature.

Next, FIG. 13 shows the result of measuring the saturation magnetization temperature characteristic of each YGIAG film when the applied magnetic field was 5 kGconst. As is clear from the figure, Sample 8 has a maximum saturation magnetization of 900 G and a compensation temperature of −150 ° C.
Sample 7 has a maximum saturation magnetization of 200G and a compensation temperature of 0 ° C.
In each sample, the change in saturation magnetization with respect to the temperature change is large near room temperature. However, sample 9 shows a state in which the change in saturation magnetization due to temperature is the sum of sample 7 and sample 8, and the change in saturation magnetization due to the change in temperature is small near room temperature.

The saturation magnetization temperature coefficient α (/ ° C.) of each YGIAG film is 10,000 × 10 ^{−6 for} sample 7 and 2800 × 10 ^{−6 for} sample 8, and α of −10 to 50 ° C. is 10 in both cases.
Although it is not less than 00 × 10 ⁻⁶ , Sample 9 shows an extremely small value of 140 × 10 ⁻⁶ . That is, a garnet film having a small saturation magnetization temperature coefficient could be obtained by the film forming method of the present invention.

Example 4 By the same LPE method as in Example 3, GG with a diameter of 50 mm was used.
On the surface of the G substrate (111), YGBIG similar to that of the second embodiment
A film was formed. The solution temperature is 980 ° C. (hereinafter referred to as sample 10), the solution temperature is 880 ° C. (hereinafter referred to as sample 11), and the substrate is moved in the solution having the temperature distribution shown in FIG. Three samples, that is, samples (hereinafter, referred to as sample 12) formed by changing the film as in FIG. 11B were formed.

FIG. 14 shows the results of measuring the distribution of the amounts of constituent elements in each of the obtained YGBIG films. As shown in the figure, the Bi amount in Samples 10 and 11 does not change in the film thickness direction, but in Sample 12, the Bi amount is 14 mol% and 5 mol%.
, And the amount of Bi changes linearly between them. From this, it was confirmed that the component composition was modulated in the film thickness direction by providing the temperature gradient in the depth direction of the solution temperature and moving the substrate to change the film formation temperature.

Next, FIG. 15 shows the results of measuring the saturation magnetization temperature characteristics of each YGBIG film when the applied magnetic field was 5 kGconst. As is clear from the figure, sample 11
Has a maximum saturation magnetization of 800G and a compensation temperature of -100 ° C.
Hereinafter, Sample 10 has a maximum saturation magnetization of 700 G and a compensation temperature of 0 ° C., and all samples show large changes in saturation magnetization with respect to temperature changes near room temperature. However, the temperature change of the saturation magnetization of the sample 12 shows a mode in which the sample 10 and the sample 11 are added, and the change of the saturation magnetization with respect to the temperature change is small near room temperature.

The saturation magnetization temperature coefficient α (/ ° C.) of each YGBIG film was 3000 × 10 ⁻⁶ for sample 10 and 11 for sample 11.
Is 1500 × 10 ^-6 and α at -10 to 50 ° C is 1
000 × 10 ^-6 or more, but sample 6 is 350 × 10 ^-6
And shows an extremely small value. That is, a garnet film having a small saturation magnetization temperature coefficient could be obtained by the film forming method of the present invention.

Example 5 FIG. 5 shows a film forming apparatus having a vertical furnace core tube structure according to the present invention.
The target composition is Y _1.77Gd_1.23Fe_3.6Al_0.8In
_0.6O₁₂So that each oxide of the compounding ratio shown in Table 1
After being put into a Pt crucible and melted and stirred at 1050 ° C.,
According to the LPE method shown in FIG. 2, a GGG substrate having a diameter of 50 mm
A film was formed on the (111) plane at a solution temperature of 869 ° C. for 10 minutes.
Sample (hereinafter sample 13), solution temperature 782 ° C for 10 minutes
Formed sample (hereinafter sample 14), during epitaxial growth
Change the solution temperature from 780 ℃ to 840 ℃ in 7.5 minutes.
Sample (hereinafter referred to as Sample 15) formed by film formation and shrimp
Solution temperature from 780 ° C to 870 in 10 minutes during growth.
4 trials of samples (hereinafter sample 16) formed by changing the temperature to ℃
The material was made.

The film thickness of each sample obtained, the temperature coefficient of the saturation magnetization and the Max temperature of the saturation magnetization in the range of ± 30 ° C. near the top of 4πMs are shown in Table 2, and the applied magnetic field was 5 kGcons.
The saturation magnetization temperature curve at t is shown in FIG. The obtained samples were all garnets having (111) orientation.

As is clear from Table 2, the sample 15 and the sample 16 according to the present invention in which the film forming temperature is changed have a smaller saturation magnetization temperature coefficient than the sample 13 and the sample 14 in which the film forming temperature is not changed. I understand. Further, as is clear from FIG. 16, in comparison with the sample 13 and the sample 14, the sample 15 and the sample 16 according to the present invention have ± 3 near the top of 4πMs.
It can be seen that the temperature change of the saturation magnetization is small in the range of 0 ° C. and the temperature curve is flattened.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

According to the present invention, it is possible to introduce a component composition modulation in the thickness direction of a grown film by using means for changing the film forming temperature during liquid phase epitaxial growth on a substrate. As is clear from the examples, it is possible to obtain a metal-based or porcelain-based functional film with the required characteristics temperature-stabilized, that is, the temperature characteristics remarkably improved.

[Brief description of drawings]

1A and 1B are explanatory views of a solution and a substrate showing the principle of the LPE method for introducing the modulation of the component composition according to the present invention.

FIG. 2 is an explanatory diagram of a solution and a substrate showing an LPE method according to the present invention for forming a film by changing the temperature of the solution.

FIG. 3 is an explanatory diagram of a solution and a substrate showing an LPE method according to the present invention for forming a film by moving the substrate in a solution having a temperature gradient.

FIG. 4 is a graph showing an example in which a temperature change due to a film formation position change is added to a temperature change in a depth direction and a plane direction of a solution.

FIG. 5 is an explanatory diagram showing a configuration of an LPE manufacturing apparatus according to the present invention.

FIG. 6 is a graph showing the relationship between film formation time and solution temperature.

7 is a graph showing Al amount distribution in the YGIAG film of Example 1. FIG.

FIG. 8 is a graph showing the saturation magnetization temperature characteristics of the YGIAG film of Example 1.

FIG. 9 is a graph showing the Bi amount distribution in the YGBIG film of Example 2.

FIG. 10 is a graph showing the saturation magnetization temperature characteristics of the YGBIG film of Example 2.

FIG. 11A is a graph showing a temperature distribution in a solution, and B is a graph showing a film forming position and a lapse of time.

FIG. 12 is a graph showing Al amount distribution in a YGIAG film of Example 3.

FIG. 13 is a graph showing the saturation magnetization temperature characteristic of the YGIAG film of Example 3.

FIG. 14 is a graph showing the Bi amount distribution in the YGBIG film of Example 4.

FIG. 15 is a graph showing the saturation magnetization temperature characteristics of the YGBIG film of Example 4.

16 is a graph showing the saturation magnetization temperature characteristic of the YGIAG film of Example 5. FIG.

[Explanation of symbols]

1 furnace core tube 2a, 2b, 2c heater 3 furnace body 4 shutter 5 solutions 6 crucibles 7 Support 8 Metal-based or porcelain-based functional film 9 Substrate holder 10 Support rod 11 gas nozzle

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 23, 2002 (2002.4.2)
3)

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

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Claims (10)

[Claims] 1. A functional film, which is a film made of a metal material or a porcelain material by liquid phase epitaxial growth, and has a component composition modulation in the thickness direction of the film. 2. The functional film according to claim 1, wherein the metal material is any one of a sulfide semiconductor, a phosphide semiconductor, a selenide semiconductor, a telluride semiconductor, and an intermetallic compound semiconductor. 3. The functionality according to claim 1, wherein the porcelain material is any one of magne plumbite porcelain, spinel porcelain, garnet porcelain, perovskite porcelain, zinc blende porcelain and wurtzite porcelain. film. 4. The garnet-based porcelain has the general formula R1 _{3-x.
R2 x Fe 5-y M y} O 12 ( where R1 and R2 Y, B
i, Ca, Pb, Sr, Ba, Cd, Cu, Mg, M
At least one of n, Cr, Na and lanthanum-based transition elements, M is Al, Ga, In, Mn, Cr, Sc,
Cu, Zn, Mg, Ni, Co, Li, Ge, Si,
(At least one of V, P, As, V, Sb, Ti)
The functional film according to claim 3, which is represented by the following formula and satisfies 0 ≦ x ≦ 3 and 0 ≦ y ≦ 5. 5. A method for forming a solute in a solution by liquid phase epitaxial growth on a surface of a substrate to form a film, which has a function of changing the temperature of the film formation so as to have a component composition modulation in the thickness direction of the grown film. Of a flexible film. 6. The method for producing a functional film according to claim 5, wherein the method of changing the film forming temperature is a method of changing the solution temperature. 7. The method for producing a functional film according to claim 5, wherein the method for changing the film formation temperature is to set a temperature gradient in the solution in advance and move the substrate in the solution. 8. The method of changing the film forming temperature is a method of controlling and holding the solution temperature in advance so that the solution temperature is lowered or raised in the depth direction of the solution, and sequentially raising and lowering the substrate in the solution.
The method for producing the functional film according to [4]. 9. The method for producing a functional film according to claim 5, wherein the change range of the film formation temperature is 100 ° C. or higher. 10. A liquid phase epitaxial growth apparatus having a vertical furnace core tube structure in which a crucible is arranged in a furnace, wherein a plurality of heaters for heating provided in the outer peripheral portion of the furnace as a means for changing a film forming temperature, The functional film manufacturing apparatus used in the manufacturing method according to claim 5, further comprising a gas nozzle that blows a gas onto the solution surface of the crucible and a cooler that cools the bottom of the crucible.