JPH10330941A - Liquid raw material feeding device for cvd - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liq. raw material feeding device for CVD capable of continuously feeding a certain amt. of liq. raw material regardless of the kinds of solvents to dissolved the raw material and the conditions of pressure, furthermore capable of improving the efficiency of coating formation and capable of forming thin coating such as oxide superconducting thin coating stable in characteristics such as coating quality. SOLUTION: This liq. raw material feeding device has a cylindrical raw material soln. feeding part 2 in which a liq. raw material is fed to the inside and a cylindrical tempered atomizing gas feeding part 3 provided so as to surround the outer circumference of the feeding part and in which atomizing gas for atomizing the liq. raw material is fed to the gap with the raw material soln. feeding part. In this case, the raw material soln. feeding part is provided with a branch pipe 5a feeding a filling gas to the raw material soln. feeding part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid for CVD provided in a thin film forming apparatus for forming an oxide material such as an oxide superconductor on a substrate by a chemical vapor deposition method (hereinafter referred to as a CVD method). The present invention relates to a raw material supply device.

[0002]

2. Description of the Related Art In recent years, as oxide superconductors whose critical temperature (Tc) is higher than liquid nitrogen temperature (about 77 K), for example, Y-Ba-Cu-O system, Bi-Sr-Ca-Cu-
Oxide superconductors such as O-based and Tl-Ba-Ca-Cu-O-based have been discovered. Various studies are being conducted on these oxide superconducting thin films for the purpose of using them in fields such as power cables, magnets, energy storage, power generators, medical devices, and current leads. As one method of manufacturing such an oxide superconductor, a method of forming an oxide superconducting thin film on a substrate surface by a thin film forming means such as a chemical vapor deposition method (CVD method) is known. The oxide superconducting thin film formed by this kind of thin film forming means,
It is known that the critical current density (Jc) is large and exhibits excellent superconducting characteristics. Among the CVD methods, the CVD method using an organic metal compound such as a metal complex or a metal alkoxide as a raw material has attracted attention as a means capable of forming a thicker film in a short time with a high film-forming speed.

As a raw material compound usually used in such a method for producing an oxide superconductor by the CVD method, a β-diketone compound or a cyclopentadienyl compound of each element constituting the oxide superconductor is used. For example, for the production of a Y—Ba—Cu—O-based oxide superconductor, Y (thd) ₃ , Ba (thd) ₂ or Ba (t)
hd) ₂ phen ₂ , an organometallic complex raw material (MO raw material) such as Cu (thd) _{2 or} the like (thd
= 2,2,6,6-tetramethyl-3,5-heptanedione). These organometallic complex raw materials are solid raw materials at room temperature, and exhibit high sublimation characteristics when heated to 200 to 300 ° C. However, the sublimation efficiency depends on the purity of the raw material and the change in the surface area of the charged raw material with heating time. Is greatly affected by the composition control. Therefore, these solid complex raw materials have been used as liquid raw materials by dissolving them in an organic solvent such as tetrahydrofuran (THF), isopropanol, toluene, diglyme (2,5,8-trioxononane).

[0004] These liquid raw materials are heated and vaporized by a vaporizer and sent to a reaction chamber together with a carrier gas.
A chemical reaction occurs in the reaction chamber. As a result, the target Y-Ba-Cu-O-based oxide superconductor can be obtained by depositing the reaction product on the surface of the base material installed in the reaction chamber. However, when a solution obtained by dissolving an organometallic complex material in an organic solvent is used as a liquid material for CVD, the liquid material supply device for CVD becomes a problem.

The present applicants have already developed a liquid material supply apparatus for CVD as shown in FIGS.
No. 311363. FIG. 6 is a schematic configuration diagram showing an example of a liquid material supply device for CVD disclosed in the application, and FIG. 7 is a cross-sectional view taken along the line BB of FIG. Reference numeral 62 denotes a raw material solution supply unit, reference numeral 62a denotes a capillary tube, reference numeral 63 denotes an atomizing gas supply unit, reference numeral 64 denotes a shield gas supply unit, and reference numeral 6
Reference numeral 5 denotes a liquid pool, reference numeral 66 denotes a nozzle, and reference numeral 67 denotes a tapered portion.

[0006] The liquid material supply device 61 is shown in FIGS. 6 and 7.
As shown in FIG. 5, a cylindrical raw material solution supply section 62, a cylindrical tapered atomizing gas supply section 63 provided around the outer periphery of the raw material solution supply section 62, and a tip of the atomized gas supply section 63 And a cylindrical shield gas supply section 64 provided around the outer periphery excluding the section.

[0007] The raw material solution supply section 62 is for supplying a liquid raw material into the inside thereof, and a liquid pool 65 for temporarily storing the supplied liquid raw material is provided at a central portion. The inner diameter of the liquid pool 65 is larger than the inner diameters of the upper raw material solution supply section 62 and the lower capillary 62a, so that the fed liquid raw material is continuously fed into the capillary 62a while accumulating. . When such a liquid pool 65 is provided, even if bubbles and the like are mixed in the liquid raw material, the bubbles and the like float on the liquid surface of the liquid raw material accumulated in the liquid pool 65 and reach the capillary tube 62a. Can be prevented.

The atomizing gas supply section 63 is provided on the outer layer of the raw material solution supply section 62, and supplies an atomizing gas for atomizing the liquid raw material. An atomizing gas supply source is connected to an upper portion of the atomizing gas supply unit 63 so that an atomizing gas can be supplied into the atomizing gas supply unit 63. If a specific example of the atomizing gas used here is specified, an argon gas, a helium gas, a nitrogen gas, or the like is used. And
In the liquid source supply device 61 of this example, a nozzle 66 is constituted by the tip of the atomizing gas supply 63 and the tip of the source solution supply 62.

The shielding gas supply section 64 is provided on an outer layer of the atomizing gas supply section 63, and supplies a shielding gas for cooling the atomizing gas supply section 63 and shielding the nozzle 66. A tapered portion 67 that protrudes outward is provided below the central portion of the shield gas supply unit 64. A shield gas supply source is connected to an upper portion of the shield gas supply unit 64 so that the shield gas can be supplied into the shield gas supply unit 64. If a specific example of the shielding gas used here is specified, an argon gas, a helium gas, a nitrogen gas, or the like is used.

In the liquid material supply device 61 having the above-described structure, the liquid material is fed into the material solution supply section 62 at a constant flow rate, and the atomizing gas is fed into the atomization gas supply section 63 at a constant flow rate. The atomized gas flows from the tip of the atomizing gas supply unit 63 outside the tip while accumulating at the tip of the capillary 62a, so that when blowing out from the nozzle 66, the liquid raw material is immediately atomized by the atomized gas, A certain amount of mist-like liquid raw material can be continuously supplied.

When the shielding gas is fed into the shielding gas supply section 64 at a constant flow rate, the atomizing gas supply section 63 and the raw material solution supply section 62 are cooled. Is also cooled, and the liquid raw material is less likely to be vaporized in the raw material solution supply unit 62. Furthermore, since the shield gas flows from the tip of the shield gas supply unit 64 outside and above the nozzle 66, the nozzle 66
Is shielded, and the vaporized liquid material is supplied to the nozzle 66
And reprecipitation can be prevented.

[0012]

The liquid raw material supply device 61 is connected to a vaporizer reduced to a pressure of about several Torr to several tens of Torr, and is used. When used for dissolution, several T
If the pressure is as low as about orr, the vapor pressure of the liquid raw material is high, so that the liquid raw material is vaporized inside the capillary tube 62a. Further, depending on the type of the solvent and the pressure conditions, the liquid raw material in the liquid pool 65 may be completely gasified before reaching the tip of the capillary tube 62a, so that stable raw material supply cannot be performed in the vaporizer. There were cases.

The present invention has been made in view of the above circumstances, and it is possible to continuously supply a fixed amount of a liquid raw material regardless of the type of solvent in which the raw material is dissolved and the pressure conditions, and to improve the film forming efficiency. CV capable of forming a thin film such as an oxide superconducting thin film having stable characteristics such as film quality.
It is an object of the present invention to provide a liquid material supply device for D.

[0014]

According to the first aspect of the present invention, there is provided a cylindrical raw material solution supply section into which a liquid raw material is supplied, and the raw material solution supply section is provided so as to surround an outer periphery of the supply section. And a cylindrical tapered atomizing gas supply unit in which an atomizing gas for atomizing the liquid material is supplied to a gap between the liquid solution supply unit and the gas supply device. A liquid supply apparatus for CVD is characterized by being provided with a branch pipe for supplying the liquid.

Further, in the invention according to claim 2, a cylindrical raw material solution supply section into which the liquid raw material is supplied, and a surrounding area provided around the outer periphery of the supply section, are provided in a gap between the raw material solution supply section. An atomizing gas supply unit for atomizing the liquid raw material is supplied, which is provided with a cylindrical and tapered atomizing gas supply unit, and a cylindrical shielding gas supply unit is provided surrounding the outer periphery of the atomization gas supply unit, A liquid source supply device for CVD having a configuration in which a shielding gas for cooling and shielding the source solution supply unit and the atomization gas supply unit is supplied to a gap between the atomization gas supply unit and the source solution supply unit. A liquid material supply apparatus for CVD characterized in that a branch pipe for supplying a filling gas is provided as means for solving the above-mentioned problem.

According to the third aspect of the present invention, there is provided a cylindrical raw material solution supply section into which a liquid raw material is supplied, and is provided so as to surround an outer periphery of the supply section. An atomizing gas supply unit for atomizing the liquid raw material is supplied, which is provided with a cylindrical and tapered atomizing gas supply unit, and a cylindrical shielding gas supply unit is provided surrounding the outer periphery of the atomization gas supply unit, A structure is provided in which a shielding gas for cooling and shielding the source solution supply unit and the atomization gas supply unit is supplied to a gap between the atomization gas supply unit and a liquid source is temporarily stored in the source solution supply unit. CV with a reservoir
A liquid material supply apparatus for CVD, wherein a branch pipe for supplying a filling gas to the material solution supply section is provided, wherein the apparatus is a liquid material supply apparatus for D.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an example of an apparatus for manufacturing an oxide superconducting conductor provided with a liquid material supply device for CVD according to the present invention. The apparatus for manufacturing this oxide superconducting conductor includes a liquid source supply apparatus 1 for CVD and a raw liquid supply apparatus 20.
, A vaporizer 30, and a CVD reactor (reactor) 40.

As shown in FIG. 2, the liquid raw material supply device 1 includes a cylindrical raw material solution supply unit 2 and a cylindrical tapered atomizing gas supply unit 3 provided around the outer periphery of the supply unit 2. And a cylindrical shield gas supply unit 4 provided so as to surround the outer periphery of the atomized gas supply unit 3 excluding the tip end thereof.

The raw material solution supply section 2 is for supplying a liquid raw material 11 fed from a raw liquid supply device 20 to be described later into the inside thereof.
A liquid pool 5 is provided to temporarily store the liquid.
The inner diameter of the liquid pool 5 is larger than the inner diameter of the upper and lower capillaries 2a of the raw material supply unit 2, and the liquid raw material 11 sent from the raw liquid supply device 20 is continuously fed to the tip while accumulating. It has become. Also,
A branch pipe 5a is provided above the liquid reservoir 5, and a filling gas supply source 5b is connected to the branch pipe 5a via a filling gas MFC (flow rate regulator) 5c. Is configured to be supplied. If a specific example of the filling gas used here is specified, an argon gas, a helium gas, a nitrogen gas, or the like is used. By supplying the filling gas, the pressure in the liquid pool 5 is kept substantially at the atmospheric pressure.

The atomizing gas supply unit 3 supplies an atomizing gas for atomizing the above-mentioned liquid raw material 11 into a gap between the raw material solution supplying unit 2 and the atomizing gas supply unit 3. An atomizing gas supply source 3a is connected to an upper portion of the atomizing gas supply unit 3 via an atomizing gas MFC 3b so that the atomizing gas can be supplied into the atomizing gas supply unit 3. If a specific example of the atomizing gas used here is specified, an argon gas, a helium gas, a nitrogen gas, or the like is used. In the liquid source supply device 1 of this example, the nozzle 6 is constituted by the tip of the atomizing gas supply unit 3 and the tip of the source solution supply unit 2.

The shielding gas supply unit 4 is for supplying a shielding gas for cooling the atomizing gas supply unit 3 and shielding the nozzle 6 to a gap between the atomizing gas supply unit 3 and the atomizing gas supply unit 3. A tapered portion 7 that protrudes outward is provided below the center of the shield gas supply unit 4. A shield gas supply source 4a is connected to an upper portion of the shield gas supply unit 4 via a shield gas MFC 4b, so that the shield gas can be supplied into the shield gas supply unit 4. If a specific example of the shielding gas used here is specified, an argon gas, a helium gas, a nitrogen gas, or the like is used.

In the liquid material supply apparatus 1 having the above-described configuration, when the liquid material 11 is fed into the material solution supply unit 2 at a constant flow rate and the atomizing gas is sent to the atomization gas supply unit 3 at a constant flow rate, the liquid material 11 is pooled The atomized gas flows from the tip of the atomizing gas supply unit 3 outside the tip while accumulating at the tip of the raw material solution supply unit 2 while accumulating at 5.
1 is immediately atomized by the atomizing gas so that a constant amount of mist-like liquid raw material 11 can be continuously supplied into the vaporizer 30. The pressure inside the vaporizer 30 is reduced to several Torr to several tens Torr, but since the filling gas is supplied to the liquid pool 5 from the branch pipe 5a, the pressure in the liquid pool 5 is almost equal to the atmospheric pressure. In this state, the liquid raw material 11 can be prevented from being vaporized in the liquid pool 5 or the capillary 2a. Further, since the shield gas flows from the tip of the shield gas supply unit 4 outside and above the nozzle 6, the periphery of the nozzle 6 is shielded by the shield gas, and the liquid raw material 1 is vaporized in the vaporizer 30.
It is possible to prevent the source gas 1 vaporized from adhering to the nozzle 6 and becoming a solid source and reprecipitating.

In the raw material supply section 2 of the liquid raw material supply apparatus 1, a raw liquid supply apparatus 20 is provided with a liquid raw material MFC 2.
It is connected via a connection pipe 21 provided with 1a. As the connection pipe 21, a pipe excellent in chemical resistance such as a pipe whose inner surface is coated with a fluororesin is used. The stock solution supply device 20 includes a storage container 22 and a pressurizing source 23, and the liquid raw material 11 is stored inside the storage container 22. As the storage container 22, a container having excellent chemical resistance such as a glass bottle is used. The pressurizing source 23 contains He inside the container 22.
By supplying gas or the like, the inside of the storage container 22 is pressurized and the liquid raw material 11 filled in the storage container 22 is connected to the connection pipe 2.
1 can be discharged at a constant flow rate.

Liquid raw material 1 stored in storage container 22
No. 1 is obtained by mixing a plurality of metal organic compounds such as an organic metal complex of a constituent metal element of a target compound to be formed into a film and a metal alkoxide so as to have a composition ratio of the target compound and dissolving the mixture in an organic solvent. If specific examples of these metal organic compounds and organic solvents are specified, Y-Ba-Cu-
Y (t) used when forming an O-based oxide superconductor
hd) ₃ , Ba (thd) ₂ or Ba (thd) ₂ · p
hen ₂ , Cu (thd) _2, etc. (thd = ₂ , ₂ , 6,
6-tetramethyl-3,5-heptanedione) and organic solvents such as tetrahydrofuran (THF), isopropanol, toluene and diglyme (2,5,8-trioxononane).

On the other hand, below the liquid material supply device 1, a container-like vaporizer 30 is provided.
The liquid material supply device 1 and the vaporizer 30 are connected to each other from the central portion to the distal end portion, which are accommodated in the vaporizer 30. A heater 31 for heating the inside of the vaporizer 30 is attached to an outer peripheral portion of the vaporizer 30, and the mist-like liquid raw material 1 sprayed from the nozzle 6 by the heater 31 is provided.
1 is heated to a desired temperature and vaporized to obtain a raw material gas. The vaporizer 30 is connected to a CVD reactor 40 via a transport pipe 33.

The CVD reaction apparatus 40 has a reaction chamber 41 made of quartz. The reaction chamber 41 is a cylindrical type having both horizontally long ends closed, and is sequentially arranged from the left side of FIG. 1 by partition walls (not shown). It is partitioned into a base material introduction part 42, a reaction generation chamber 43, and a base material lead-out part 44. Further, the base material introduction part 42
In the base member, an introduction hole for introducing the tape-like base material 45 is formed, and in the base member leading portion 44, a lead hole for leading the base material 45 is formed. Although not shown in the drawing, the gap between the holes is closed at the peripheral portion of the hole while the substrate 45 is passing through the substrate introducing portion 4.
There is provided a sealing member for holding the base member 2 and the base member lead-out portion 44 in an airtight state. Further, a pyramid-shaped gas diffusion portion 46 communicating with the reaction generation chamber 43 is attached to the ceiling of the reaction generation chamber 43.

On the other hand, outside the CVD reactor 40, a heater 4 is provided to cover a portion of the base material introduction portion 42 on the side of the reaction generation chamber 43 from a portion of the base material introduction portion 44 on the side of the reaction generation chamber 43.
7 is provided, and the base material introduction section 42 is provided with an inert gas supply source 48.
In addition, the base material outlet 44 is connected to an oxygen gas supply source 49. In addition, a transport pipe 33 connected to the vaporizer 30 of the raw material gas is connected to the gas diffusion section 46. Around the transport pipe 33, the raw material gas is
A heating means (not shown) is provided for preventing the precipitation. Note that an oxygen gas supply source 34 is branched and connected to an intermediate portion of the transport pipe 33 so that oxygen gas can be supplied into the transport pipe 33.

Further, a gas exhaust pipe 50 is provided at the bottom of the CVD reactor 40 and is connected to a pressure regulator 52 having a vacuum pump 51 so that the gas inside the CVD reactor 40 can be exhausted. It has become. Further, on the side of the substrate outlet section 44 of the CVD reactor 40, a substrate transport mechanism including a tension drum 53 and a winding drum 54 for winding a substrate 45 passing through the inside of the CVD reactor 40. 55 are provided. Further, on the side of the base material introduction part 42, the base material 45 is
Drum 56 and delivery drum 5 for supplying
7 is provided.

Next, the source gas obtained by vaporizing the liquid source 11 is sent to the reaction chamber 41 by using the manufacturing apparatus of the oxide superconducting conductor having the liquid source supply device configured as described above. A case in which an oxide superconducting thin film is formed on a substrate 45 having a shape and a superconducting oxide conductor is manufactured will be described.

In order to manufacture an oxide superconductor using the manufacturing apparatus shown in FIG. 1, first, a tape-shaped base material 45 and a liquid raw material 11 are prepared. As the substrate 45, a long one can be used. In particular, it is preferable that the upper surface of a heat-resistant metal tape having a low coefficient of thermal expansion is coated with a ceramic intermediate layer. As a constituent material of the heat-resistant metal tape, a metal material or alloy such as silver, platinum, stainless steel, copper, and Hastelloy (such as C276) is preferable. In addition, other than the metal tape, tapes made of various ceramics such as various glass tapes or mica tapes may be used. Next, the material constituting the intermediate layer is YSZ (yttrium-stabilized zirconia) whose thermal expansion coefficient is closer to that of the oxide superconductor than metal.
SrTiO ₃ , MgO, Al ₂ O ₃ , LaAlO ₃ , LaG
Ceramics such as aO ₃ , YAlO ₃ , and ZrO ₂ are preferable, and among them, it is preferable to use ceramics having as good a crystal orientation as possible.

Next, the liquid raw material 11 for producing the oxide superconductor by the CVD reaction is prepared by mixing a metal organic compound such as an organometallic complex or a metal alkoxide of a metal element constituting the target compound to be formed into a film with the composition of the target compound. It is possible to use a mixture obtained by mixing a plurality of types so as to have a ratio and dissolving the same in an organic solvent such as THF. When such a liquid material 11 is prepared, it is filled in the storage container 22.

After the tape-shaped base material 45 is prepared, it is fed into the reaction chamber 41 from the base material introduction portion 42 by the base material transfer mechanism 58 at a predetermined moving speed, and is wound around the base material transfer mechanism 55. It is wound up by a take-up drum 54, and the substrate 45 in the reaction generation chamber 43 is further heated to a predetermined temperature by a heater 47. Before the substrate 45 is fed, an inert gas is sent from the inert gas supply source 48 into the reaction chamber 41 as a purge gas, and at the same time, the pressure adjusting device 52 is used.
It is preferable to clean the inside of the reaction chamber 41 by removing unnecessary gas such as air in the reaction chamber 41 by activating the gas to remove the gas inside the reaction chamber 41.

When the substrate 45 has been sent into the reaction chamber 41, oxygen gas is sent from the oxygen gas supply source 49 into the reaction chamber 41, and then the pressurized source 23 and the MFC 2
1a, the flow rate of the liquid raw material 11 from the storage container 22 is set to 0.1.
The solution is fed into the raw material solution supply unit 2 at about 1.0 ccm, and at the same time, the atomizing gas is sent to the atomizing gas supply unit 3 at a flow rate of about 200 to 300 ccm, and the shielding gas is sent to the shielding gas supply unit 4 at a flow rate of 200 to 300
Send in about ccm. At the same time, the pressure adjusting device 52
Is operated to exhaust the gas inside the reaction chamber 41.
At this time, the temperature of the shielding gas is adjusted to be about room temperature. The heater 31 is adjusted so that the internal temperature of the vaporizer 30 becomes the optimum temperature of the raw material having the highest vaporization temperature among the raw materials.

Then, the liquid raw material 11 reaches the tip of the raw material solution supply unit 2 while accumulating in the liquid pool 5, and thereafter, when blowing out from the nozzle 6, is immediately atomized by the atomizing gas flowing from the atomizing gas supply unit 3. Therefore, the mist-like liquid raw material 11 having a constant flow rate is continuously supplied into the vaporizer 30. Then, the mist-like liquid raw material 11 supplied to the inside of the vaporizer 30 is heated by the heater 31 to be vaporized and becomes a raw material gas, and this raw material gas is continuously supplied to the gas diffusion unit 46 via the transport pipe 33. Supplied to
At this time, the heating means adjusts the internal temperature of the transport pipe 33 so as to be the optimum temperature of the raw material having the highest vaporization temperature among the raw materials. At this time, an operation of supplying oxygen gas from the oxygen gas supply source 34 and mixing oxygen into the source gas is also performed.

Next, inside the reaction chamber 41, the raw material gas flowing out of the outlet of the transport pipe 33 to the gas diffusion section 46 moves to the reaction generation chamber 43 side while diffusing from the gas diffusion section 46, The gas moves through the inside of the generation chamber 43, and then moves near the base material 45 so as to be drawn into the gas exhaust pipe 50. Therefore, the source gas can be reacted on the heated upper surface side of the base material 45 to form an oxide superconducting thin film. By continuously performing the above-described film forming operation for a predetermined time, it is possible to obtain the oxide superconducting conductor 70 including the substrate 45 and the oxide superconducting thin film having a desired thickness and a stable film quality.

The above-described apparatus for producing an oxide superconducting conductor comprises:
Since the liquid source supply device 1 having the above-described configuration is provided, the liquid source 11 is fed into the source solution supply unit 2 at a constant flow rate, and the atomizing gas is sent to the atomization gas supply unit 3 at a constant flow rate. The raw material 11 reaches the tip of the raw material solution supply unit 2 while accumulating in the liquid pool 5 and thereafter, when blowing out from the nozzle 6, the atomizing gas supply unit 3
Since the atomized gas is immediately atomized by the atomizing gas flowing therefrom, a constant amount of the mist-like liquid raw material 11 can be continuously supplied into the vaporizer 30. The pressure inside the vaporizer 30 is reduced to several Torr to several tens Torr, but since the filling gas is supplied to the liquid pool 5 from the branch pipe 5a, the pressure in the liquid pool 5 is almost equal to the atmospheric pressure. In this state, the liquid raw material 11 can be prevented from being vaporized in the liquid pool 5 or the capillary 2a. Further, the periphery of the nozzle 6 is shielded by the shield gas, so that it is possible to prevent the raw material gas from adhering to the nozzle 6 and becoming a liquid raw material 11 and being deposited in the vaporizer 30.

Therefore, according to the apparatus for manufacturing an oxide superconductor provided with the liquid material supply device 1, a constant amount of the mist-like liquid material 11 can be continuously and stably supplied into the vaporizer 30. Since the raw material gas obtained by vaporizing the liquid raw material 11 can be continuously supplied to the reaction chamber 41 by a fixed amount, the pressure and temperature of the reaction chamber 41 are less likely to fluctuate, and As a result, a good oxide superconducting thin film having stable film quality and superconducting characteristics can be formed. Further, according to the manufacturing apparatus, since the liquid raw material 11 supplied into the vaporizer 30 is in the form of a mist,
Since the vaporization efficiency is improved, the supply speed of the liquid raw material 11 can be increased, and there is an advantage that the film formation efficiency is improved.

[0038]

【Example】

(Example) A Y-Ba-Cu-O-based oxide superconductor was manufactured as follows using an apparatus for manufacturing an oxide superconductor having the structure shown in FIG. As the liquid material supply device for CVD, one having the shape shown in FIGS. 2 and 3 was used. Y (thd) ₃ , Ba (thd) ₂ , Cu (thd)
₂ in a molar ratio of Y: Ba: Cu = 1.0: 2.4: 3.3
Was dissolved in a diglyme solution at a ratio of 1 and stored in a storage container. The raw material solution was continuously supplied to the raw material solution supply unit at a flow rate of 0.2 ml / min by a pressure source and a liquid micro MFC. At the same time, Ar as an atomizing gas was fed into the atomizing gas supply unit at a flow rate of about 300 ccm, and Ar as a shielding gas was sent into the shielding gas supply unit at a flow rate of about 300 ccm. At this time, the temperature of the vaporizer and the transport pipe was 240 ° C.

The moving speed of the substrate in the reaction chamber is 30 cm /
h, the substrate heating temperature is set to 760 ° C., the internal pressure of the reactor (CVD reactor) is set to 5 Torr, and the oxygen gas flow rate from the oxygen gas supply source is set to 50 to 100 ml / min.
Ba-Cu-O-based oxide superconducting thin films were continuously formed. As the base material, a material in which a YSZ (yttrium-stabilized zirconia) plane orientation intermediate layer was formed on a haster tape by an ion beam assisted sputtering method (width 1 cm × length 長 30 cm × thickness 0.02 cm) was used. .

(Comparative Example) The above-described embodiment was carried out except that an apparatus for manufacturing an oxide superconductor having a liquid material supply device for CVD shown in FIG. 6 was used instead of the liquid material supply device for CVD shown in FIG. An oxide superconducting thin film was formed on a substrate in the same manner as in the example.

Next, FIG. 4 shows the results of measuring the temperature change at the center of the reactor in the above-mentioned Examples and Comparative Examples. FIG.
4A, the pressure inside the vaporizer is set to 50 Torr. In FIG. 4A, the solid line indicates the relationship between the time in the embodiment and the temperature at the center of the reactor, and the broken line indicates the comparative example. And the temperature at the center of the reactor. In FIG. 4B, the pressure inside the vaporizer is set to 10
In FIG. 4 (b), the solid line indicates the relationship between the time in the embodiment and the temperature at the center of the reactor, and the broken line indicates the relationship between the time in the comparative example and the temperature at the center of the reactor. It shows the relationship.

As is clear from FIGS. 4A and 4B,
In the example, even when the pressure inside the vaporizer was 10 Torr, the temperature at the center of the reactor was 800 ° C. ± 0 ° C., and no temperature change was observed. In contrast, in the comparative example,
No temperature change was observed when the pressure inside the vaporizer was 50 Torr, but the pressure inside the vaporizer was 10 Torr.
In, the temperature at the center of the reactor was 800 ° C. ± 10 ° C., and a temperature change was observed. That is, under the thin film forming conditions of the embodiment, the pressure inside the vaporizer is set to 10 Torr.
Although it is possible to stably supply the raw material solution, in the comparative example, the pressure inside the vaporizer is set to 10 Torr.
If it is r, the supply of the raw material solution cannot be performed stably.

In Examples and Comparative Examples, a tape-shaped oxide superconductor obtained by setting the pressure inside the vaporizer to 10 Torr was subjected to Ag coating on a central portion side of the oxide superconductor by a sputtering apparatus. Further, Ag electrodes are formed on both end sides, respectively.
After the coating, a heat treatment was performed at 500 ° C. for 2 hours in a pure oxygen atmosphere to obtain a measurement sample. Then, these samples were cooled to 77 K with liquid nitrogen, and the critical current density (J
The result of measuring c) is shown in FIG. In FIG. 5, the solid line shows the critical current density at each position in the length direction of the oxide superconductor obtained in the example, and the broken line shows the critical current density in the length direction of the oxide superconductor obtained in the comparative example. It shows the critical current density for each position.

As is clear from FIG.
Oxide superconducting conductor has a critical current density variation in the longitudinal direction.
Less sticking, and 1.0 × at any point
10 ^FiveA / cm^Two(77K, 0T) or more characteristics are obtained,
Good acid with stable superconductivity in the length direction of the substrate
It can be seen that a nitride superconducting thin film is formed. to this
On the other hand, the oxide superconducting conductor obtained in the comparative example
Of the critical current density is large, and
Therefore, the critical current density is 1.0 × 10^FiveA / cm^Two(77
K, 0T), indicating that the value of
As a result, an oxide superconducting thin film with unstable superconducting properties is formed.
You can see that it is.

[0045]

As described above, in the liquid material supply apparatus for CVD of the present invention, the pressure in the material solution supply section is kept close to the atmospheric pressure. Evaporation can be prevented. Further, when the liquid material supply device for CVD of the present invention is provided in the thin film forming apparatus, a constant amount of mist-like liquid material can be continuously and stably supplied into the vaporizer, so that the liquid material is vaporized. Can be continuously supplied to the reaction chamber in a fixed amount, the pressure and temperature of the reaction chamber are less likely to fluctuate, and a good oxide with stable properties such as film quality in the length direction of the base material. A thin film can be formed. Furthermore, since the liquid source supplied into the vaporizer is in the form of a mist, there is an advantage that the vaporization efficiency is improved, the supply speed of the liquid source can be increased, and the film formation efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of an apparatus for manufacturing an oxide superconducting conductor including a liquid material supply apparatus for CVD according to the present invention.

FIG. 2 is an enlarged view showing the liquid material supply apparatus for CVD according to the present invention shown in FIG. 1;

FIG. 3 is a sectional view taken along line AA of the apparatus for supplying a liquid material for CVD in FIG. 2;

FIG. 4 is a diagram showing the relationship between time and the temperature at the center of the reactor.

FIG. 5 is a diagram showing critical current densities in the length direction of the oxide superconductor obtained in Examples and Comparative Examples.

FIG. 6 is a schematic configuration diagram showing an example of a liquid material supply device for CVD disclosed in Japanese Patent Application No. 7-313363.

FIG. 7 is a sectional view taken along the line BB of the liquid material supply apparatus for CVD in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid raw material supply apparatus, 2 ... Raw material solution supply part, 3 ... Atomized gas supply part, 4 ... Shield gas supply part, 5 ... Liquid pool, 5a ... Branch pipe, 5b ... Filling gas supply source

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Saito 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. Address No. 1 Chubu Electric Power Co., Inc.

Claims (3)

[Claims] 1. A tubular raw material solution supply unit into which a liquid raw material is supplied, and a liquid material supply unit is provided so as to surround an outer periphery of the supply unit.
A liquid source supply device for CVD comprising a tubular and tapered atomizing gas supply unit in which an atomizing gas for atomizing the liquid source is supplied to a gap between the source solution and the source solution. A liquid material supply device for CVD, characterized in that a supply pipe is provided with a branch pipe for supplying a filling gas. 2. A tubular raw material solution supply unit into which a liquid raw material is supplied, and a liquid material supply unit is provided so as to surround an outer periphery of the supply unit.
A cylindrical taper atomizing gas supply unit for supplying an atomizing gas for atomizing the liquid raw material to a gap between the raw material solution supplying unit and the cylindrical shielding gas supply unit; CV which is provided so as to surround the outer periphery of the unit, and has a configuration in which a shield gas for cooling and shielding the raw material solution supply unit and the atomization gas supply unit is supplied to a gap between the atomization gas supply unit.
A liquid material supply device for CVD, wherein a branch pipe for supplying a filling gas to the material solution supply section is provided. 3. A cylindrical raw material solution supply unit into which a liquid raw material is supplied, and a supply unit surrounding the outer periphery of the supply unit;
A cylindrical taper atomizing gas supply unit for supplying an atomizing gas for atomizing the liquid raw material to a gap between the raw material solution supplying unit and the cylindrical shielding gas supply unit; The raw material solution supply unit and a shielding gas for cooling and shielding the atomization gas supply unit are provided in a gap between the atomization gas supply unit and the gas supply unit. A liquid material supply device for CVD, wherein a liquid pool for temporarily storing a liquid material is provided, wherein a branch pipe for supplying a filling gas to the material solution supply section is provided. Liquid raw material supply device.