JP3118493B2 - Liquid material CVD equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a thin film, for example, a dielectric thin film such as a semiconductor memory by a chemical vapor deposition (CVD) method. Hereinafter, the chemical vapor deposition apparatus is referred to as a CVD apparatus.

[0002] More specifically, the present invention relates to a CVD apparatus for forming a thin film using an organic solvent in which an organometallic compound is dissolved.

[0003]

2. Description of the Related Art In recent years, in particular, integration of memory devices has been rapidly advanced in the field of semiconductor devices. For example, in dynamic random access memory (DRAM)
In order to increase the speed, lower the power consumption, and lower the cost of devices, the number of bits has been rapidly increased by four times in three years. However, no matter how the degree of integration is improved, a capacitor, which is a component of a DRAM, must have a certain capacity to hold a required amount of charge. For this reason, it is necessary to reduce the film thickness of the capacitor material, and there has been a limit to the thinning of the SiO ₂ used up to that time. Therefore, if the dielectric constant can be increased by changing the material, the capacity can be secured as in the case of thinning, so research using a high dielectric constant dielectric material for memory devices has recently attracted attention. .

As the performance required of such a capacitor material, it is most important that the thin film has a high dielectric constant as described above and that the leakage current is small. That is, as long as a material having a high dielectric constant is used, it is necessary to make the film as thin as possible and to minimize the leak current. For example, as a general development target, it is generally considered desirable that the film thickness in terms of SiO ₂ be 1 nm or less, and the leak current density when applying 1.65 V be 10 ^-8 A / cm ² or less. In addition, in order to form a thin film on a capacitor electrode of a DRAM having a step, it is necessary to form a thin film by a CVD method which has good adherence to an object having a complicated shape, that is, can uniformly form a film on a complicated shape. The ability of the membrane is very advantageous in the process. From such a viewpoint, tantalum oxide, lead zirconate titanate (PZT),
Oxide-based dielectric films such as lanthanum lead zirconate titanate (PLZT), strontium titanate, and barium titanate have been applied. Various film forming methods have been studied to achieve a thin film using these materials.
Although it is most advantageous to form a film by the method, there is a serious problem that there is no material having stable and good vaporization characteristics as a CVD material at present.
This is mainly due to the fact that β
-This is due to the poor vaporization characteristics of the diketone-based dipivaloylmethane (DPM) compound due to heating. This point is pointed out in, for example, the 52nd JSAP Symposium Proceedings No. 9a-P-11.
It is believed to be a drawback due to the intrinsic instability of metals and compounds of DPM.

[0005] Nevertheless, as disclosed in, for example, the 52nd Annual Meeting of the Japan Society of Applied Physics, Proceedings No. 9a-P-6, the CVD method has been actively studied, and the instability of the raw materials as described above has been studied. Therefore, in an extreme case, a situation has arisen in which a raw material must be disposable and a film must be formed. Therefore, due to the drawbacks caused by said raw materials,
The technology for producing a dielectric thin film having good performance and good production reproducibility has not yet been established.

[0006] Under such circumstances, some of the present inventors dissolve conventional solid raw materials in tetrahydrofuran to form a solution.
A VD raw material was proposed (Japanese Patent Application No. Hei 4-252836). However, it has been found that good results cannot always be obtained even when a dielectric film is produced by using this raw material in a conventional liquid source CVD apparatus for producing a SiO ₂ film or the like.

FIG. 16 is a schematic diagram showing an outline of the most common conventional liquid material CVD apparatus. The details of such an apparatus are described in, for example, pages 226 and 227 of the CVD Handbook edited by the Society of Chemical Engineers (1991, published by Asakura Shoten). In FIG. 15, 1 is a carrier gas transport pipe such as argon, 2 is a carrier gas supplier, 3 is a raw material container / vaporizer (bubbler) 4 is a heating means,
Reference numeral 5 denotes a source gas transport pipe, 6 denotes a heating means, 7 denotes a reaction furnace, 8 denotes a substrate on which a thin film is formed, and 9 denotes a reaction gas transport pipe.

[0008]

However, an organic solvent solution of a metal compound such as DPM (hereinafter referred to as an organometallic compound including a metal enolate of a β-diketone compound such as DPM) is used as a raw material solution as described above. When the raw material solution is heated by the heating means 4 in the raw material container / vaporizer 3 when using the liquid raw material CVD apparatus, the vaporization of the organic solvent proceeds faster due to the difference in vapor pressure of the raw material components, and the solution concentration As a result, the concentration of the raw material gas sent to the reaction furnace changes, and it is inevitable that a serious problem occurs in obtaining a dielectric film having a desired composition. That is, since the concentration and vaporization state of the raw material in the solution change with time, inhomogeneity such as composition deviation of the formed film increases, and it is inevitable that leak current as the dielectric film for the capacitor increases. Was. Also, due to the change over time of the concentration of the raw material solution during the film formation,
There has been a problem that granular precipitates are formed on the wall surface of the raw material solution / vaporizer 3 and the inner surface of the raw material gas transport pipe 5, and in the worst case, clogging occurs. These problems become more remarkable when a solution in which an organic metal compound is dissolved in an organic solvent is used as a raw material.

An object of the present invention is to provide the above-mentioned conventional liquid raw material C
The purpose of the VD apparatus is to eliminate the disadvantages particularly when an organic solvent solution of an organometallic compound is used as a raw material. During the vaporization of the raw material solution and the film formation, the concentration and vaporization of the solution in the raw material container are reduced. An object of the present invention is to provide a CVD apparatus capable of preventing a particle from being deposited or clogged in a vaporizer or a transport pipe by suppressing a change in a state, and capable of forming a thin film having good performance without composition deviation.

[0010]

According to the present invention, there is provided a CVD apparatus comprising: a raw material container for storing a raw material solution; means for preliminarily atomizing the raw material solution; a vaporizer for vaporizing the atomized raw material solution by heating; C for liquid raw material, comprising: a source gas transport pipe for transporting a source gas; and a reaction furnace having a heating means for the source gas introduced from the source gas transport pipe.
It relates to a VD device.

[0011] The CVD apparatus of the present invention further comprises a nozzle for the vaporizer to atomize and introduce the raw material solution, and a heating means for vaporizing the atomized raw material solution. It is preferable to include a liquid supply means for supplying the liquid from the nozzle to the nozzle.

[0012] In the CVD apparatus of the present invention, the vaporizer may be arranged such that the vaporizer ejects the atomized raw material solution from the nozzle in the middle of the flow path to the raw material gas transport pipe with respect to the flow of the atomized raw material solution. Alternatively, it is preferable to have one or two or more vaporizing plates provided at an angle so as to prevent the flow path.

It is preferable that the CVD apparatus of the present invention further comprises a carrier gas blowing pipe in which the vaporizer is heated.

[0014] In the CVD apparatus of the present invention, the heated carrier gas blowing pipe may open toward the atomized raw material solution ejected from the nozzle immediately before the nozzle for atomizing and ejecting the raw material solution. Preferably,

In the CVD apparatus of the present invention, the heated carrier gas blow-out pipe may have a structure in which gas is blown toward the inner wall surface of the vaporizer and / or a vaporizing plate provided inside the vaporizer. Is preferred.

In the CVD apparatus according to the present invention, the atomizing means is an ultrasonic atomizing means provided in the raw material solution, and is used for supplying the atomized raw material solution from the raw material solution to a vaporizer. It is preferable to have an inlet tube.

Preferably, the CVD apparatus of the present invention further comprises a solvent replenishing means for replenishing the raw material solution with an organic solvent.

In the CVD apparatus of the present invention, it is preferable that the inner wall of the vaporizer is coated with a layer containing a material for preventing the polymerization of the raw material solution.

In the CVD apparatus of the present invention, it is preferable that the material for preventing the polymerization comprises a metal powder, an alkali agent or a reducing agent.

In the CVD apparatus of the present invention, it is preferable that the inner wall surface and / or the vaporizing plate of the vaporizer are covered with a porous body made of a material having good heat conductivity.

[0021] In the CVD apparatus of the present invention, it is preferable that the inner wall surface of the vaporizer has an uneven surface.

In the CVD apparatus according to the present invention, the vaporizer is heated by circulating hot oil to a heating section around the vaporizer. The outside of the vaporizer main body and the heating section is made of a transparent material. It is preferred that it be done.

The CVD apparatus of the present invention is preferably provided with a filter having fine holes between the vaporizer and the raw material gas transport pipe according to the first aspect.

In the CVD apparatus of the present invention, it is preferable that the inner wall surface of the vaporizer is coated with a material having low surface activity and high heat resistance.

[0025]

When the CVD apparatus of the present invention is used, the raw material solution stored in the raw material container is atomized inside or outside the vaporizer and then vaporized inside the vaporizer, so that the raw material gas having a uniform concentration is obtained. Thus, a uniform thin film can be obtained by the CVD method in the reactor.

In the CVD apparatus according to the present invention, the flow of the raw material solution which is sprayed from a nozzle into the vaporizer and is atomized is obstructed in the flow path of the raw material solution. When a vaporizer having one or two or more vaporizing plates provided at such an angle is used, the unvaporized atomized raw material solution adheres to the vaporizing plate and easily evaporates.

Further, in the CVD apparatus of the present invention, a heated carrier gas blowing pipe opened toward the atomized material solution ejected from the nozzle immediately before the nozzle for atomizing and ejecting the material solution, In addition, when a vaporizer having a heating means for vaporizing the atomized raw material solution is used, a temperature drop due to adiabatic expansion of the atomized raw material ejected from the nozzle is prevented.

Further, in the CVD apparatus of the present invention, when the heated carrier gas blowing pipe uses a vaporizer having a structure in which a gas is blown toward an inner wall surface and / or a vaporizing plate of the vaporizer. The atomized raw material solution attached to the vaporizing plate is easily vaporized.

Further, when the CVD apparatus of the present invention is used, the raw material solution is atomized by ultrasonic waves in the raw material container in advance, so that the vaporization occurs uniformly and sufficiently in the vaporizer.

Further, when the CVD apparatus of the present invention is used, the concentration of the raw material solution in the raw material container can always be kept constant by the means for replenishing the raw material solution stored in the raw material container with a solvent.

Further, in the CVD apparatus of the present invention, if a vaporizer in which the inner wall of the vaporizer is coated with a layer containing a material for preventing the polymerization of the raw material solution is used, even if the vaporizer is used for a long period of time, the vaporizer is attached to the inner wall. Kimono does not occur and vaporization is performed stably.

In the CVD apparatus of the present invention, if a vaporizer having an uneven inner wall surface is used, the adhesion area of the unvaporized raw material solution becomes large, Becomes easier.

Further, in the CVD apparatus of the present invention, if the vaporizer that heats by circulating hot oil to the surrounding heating section is used, it is easy to keep the temperature inside the vaporizer uniform.

Further, in the CVD apparatus of the present invention, when the outside of the vaporizer main body and the heating section is made of a transparent material, the inside can be visualized, and the maintainability is improved.

In the CVD apparatus of the present invention, when a filter having fine holes is provided between the vaporizer and the raw material gas transport pipe, unvaporized raw materials and fine powder generated in the vaporizer react. It can be prevented from being sent to the furnace, and contamination of the reactor can be prevented.

Further, in the CVD apparatus of the present invention, if the vaporizer having an inner wall surface having low surface activity is used, it is possible to prevent the unvaporized raw material from adhering to the inner wall of the vaporizer.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of the present invention forms a thin film by a CVD method such as acetylacetonate such as titanium, strontium, lead, and zirconium, or dipivaloylmethanate, which is difficult to vaporize at a uniform concentration. This is a device that is particularly effective when an organic solvent solution of the compound used in the above is used. That is, the liquid raw material,
It is configured such that once it is atomized and easily vaporized, it is vaporized by heating in a vaporizer, and the vaporized gas is introduced into a reaction furnace to form a thin film (hereinafter, referred to as film formation).

The material of the vaporizer is not particularly limited, but a transparent material such as hard glass or a material having good heat conductivity such as aluminum is preferably used. When a transparent material is used, it is easy to monitor the inside and maintenance is easy. When a material having good heat conductivity is used, the temperature distribution inside the vaporizer can be easily made uniform, and a source gas having a uniform concentration can be easily obtained.

The inner wall of the vaporizer is made of a porous metal or S
It may be covered with a porous ceramic body made of a material having good heat conductivity such as iC, BeO, or AlN.

In the above configuration, various modes can be adopted for the vaporizing method and the vaporizer. This will be described with reference to the following examples.

[0041] [Reference Example 1] FIG. 1 is a system configuration diagram showing an Example of C VD device. Reference numerals 5 to 9 are the same as those in the configuration diagram of the conventional CVD apparatus shown in FIG. Reference numeral 10 denotes a raw material container, 11 denotes a liquid supply unit, 12 denotes a nozzle, 13 denotes a vaporizer, and 14 denotes a heater of the vaporizer. Although only one raw material container 10 is shown in FIG. 1, when the raw material solution has a plurality of multi-component systems, the raw material containers are used in the same number as the number of the solutions, and the supply amount of each solution to the nozzle is a thin film. It is controlled so as to have a ratio according to the components.

Further, even in the case of a multi-component system, the composition ratio can be determined in advance and mixed in one raw material container as shown in FIG.

In the CVD apparatus configured as described above, the raw material solution in the raw material container 10 passes through the liquid raw material transporting pipe 23 in a necessary amount and is supplied to the liquid supply device 11 having a mass flow meter, for example, a fixed amount pump, a precision mass flow meter. It is sent to the vaporizer 13 by a controller or the like. At this time, the raw material sent in the liquid state is supplied to the vaporizer 1 by the nozzle 12.
It is ejected into 3 and becomes mist. In the nozzle, the injected raw material solution is turned into mist-like fine particles (hereinafter, referred to as atomization).
The diameter of the spout is desirably about 0.1 to 0.3 mm so as to facilitate vaporization.

By the injection from the nozzle, the raw material solution is
It becomes a mist of about 10 to 10 μm and is vaporized by heat from a heating means 14 provided around the vaporizer, for example, an electric heater. After the raw material solution is vaporized, the raw material solution passes through a raw material gas transport pipe 5 in the same manner as in a conventional apparatus, and is heated by a heating means 6 such as a heater.
And is reacted with a reaction (oxidation) gas sent from a reaction gas transport pipe 9 to be deposited as a film on a substrate 8 such as a semiconductor wafer as an oxide.

[0045] with C VD apparatus Experimental Example 1 above-described configuration, by forming a SrTiO ₃ is a titanate Sutorochiumu based oxide dielectric film on the magnesium oxide substrate. However, the raw material system was binary, and a tetrahydrofuran solution of acetylacetonate of Sr and Ti was used as a starting material. Both raw material solutions were ejected from a nozzle into a vaporizer by a liquid supply device and vaporized. At this time, the temperature of the vaporizer was set to 210 ° C. The reaction gas vaporized in the vaporizer was sent to a reaction furnace, where it was reacted with oxygen gas at a furnace pressure of 8 Torr and a substrate temperature of 700 ° C. for 10 minutes. After the reaction, the resultant was naturally cooled to room temperature in an oxidizing gas flow, and an oxide dielectric film having a thickness of about 50 nm was obtained. The orientation of the crystal axis was examined by X-ray diffraction, and the dielectric constant and the leak current density when a DC voltage of 1.65 V was applied were measured. Table 1 shows the results.

[0046] Using Comparative Experiment Example 1] The same raw material solution and synthesis conditions, by conventional CVD apparatus having the structure as shown in FIG. 16, and forming the oxide-based dielectric film having the same composition, Reference As in the case of using the apparatus of Example 1 , the reaction was allowed to cool naturally to room temperature in an oxygen stream after the reaction to obtain a film having almost the same thickness. This film was similarly evaluated for film quality and performance. Table 1 shows the results.

[0047]

[Table 1] As is clear from Table 1, according to the apparatus of Reference Example 1, FIG.
It is possible to form a dielectric thin film having better performance than by using the conventional apparatus shown in FIG. 6 by the CVD method. In particular, the leakage current is 1
We were able to keep it smaller than an order of magnitude. In addition, film formation was performed 10 times continuously under the same conditions as above, and the reproducibility of the film formation was examined. The film obtained by the apparatus of Reference Example 1 showed a large variation in both the relative dielectric constant and the leak current density. No reproducibility was found. On the other hand, in the film formed by the conventional CVD apparatus, both the relative dielectric constant and the leak current density showed extremely large variations with respect to the values shown in Table 1.

After the experiment, when the apparatus was disassembled and the inside of the raw material gas transport pipe and the inside of the vaporizer were examined, a large amount of white granular product adhered to the conventional apparatus, whereas the apparatus of Reference Example 1 It was confirmed that this was hardly seen.

[0049] [Reference Example 2] FIG 2 is a system configuration diagram showing another reference example of CVD apparatus of the present invention. In FIG. 2, 1, 2, and 5 to 9 are the same as those in the configuration diagram of the conventional CVD apparatus shown in FIG.
10 is a raw material container, 15 is a solvent replenisher, and 16 is an ultrasonic atomizer. Although only one raw material container 10 is shown in FIG. 2, when the raw material solution has a plurality of multi-component systems, the raw material containers are used by the number of types of the solution, and the supply amount of each solution to the nozzle is a thin film. It is controlled so as to have a ratio according to the components.

In addition, even in the case of a multi-component system, the composition ratio can be determined in advance and mixed in one raw material container as shown in FIG.

In the CVD apparatus configured as described above, the raw material solution in the raw material container 10 is atomized by the ultrasonic atomizer 16 and a required amount of the carrier gas is supplied to the carrier gas supply device 2.
The carrier gas is supplied to the vaporizer 13 through the atomized raw material transport pipe 5a. At this time, in order to prevent the raw material concentration of the solution in the raw material container from changing with time, an organic solvent is appropriately supplied into the raw material container 10 by the solvent replenisher 15. In addition, as a carrier gas, an inert gas such as argon, helium, and xenon is used. The raw material sent in the form of a mist is heated and vaporized in the vaporizer 13 and is supplied to the reaction furnace 7 in the same manner as in the case of the apparatus configuration of FIG.
And reacts with the reaction (oxidation) gas supplied from the reaction gas transport pipe 9 to deposit on the substrate 8 as an oxide.

[Experimental example 2] The raw material system was ternary,
Using a VD apparatus, an attempt was made to form a ternary oxide-based dielectric using Pb, Zr and Ti derivatives as starting materials. 3 above
Each type of dipivaloyl methanate was dissolved in tetrahydrofuran to obtain a raw material solution, and the solution was fed into a vaporizer while being atomized by an ultrasonic atomizer. In this case, 2ml for 5 minutes
, Tetrahydrofuran was injected into the raw material container from the solvent replenisher using a pump. The optimum injection amount was confirmed in advance by preliminary experiments. The temperature of the vaporizer was set to 200 ° C., and argon was used as a transport (carrier) gas. As the substrate, magnesium oxide was used, the substrate temperature was set to 630 ° C., and a PZT-based oxide dielectric film was formed. The thickness of the formed film was 110 nm. The obtained film was evaluated for film quality and performance in the same manner as in Experimental Example 1.

[Comparative Experimental Example 2] Using the same raw material solution, an oxide-based dielectric film having the same composition was formed by a conventional CVD apparatus. Reference example 2
After the reaction, the film was allowed to cool naturally to room temperature in an oxygen stream after the reaction to obtain a film having almost the same thickness. This film was similarly evaluated for film quality and performance.
Table 2 shows the results.

[0054]

[Table 2] From Table 2, as in the case of Experimental Example 1, the CVD of Reference Example 2 was performed.
It was found to be capable of forming a film by CVD of a good dielectric thin film performance than with the conventional CVD apparatus according to the apparatus. In particular, the leak current was able to be suppressed to 1/10 or less as compared with the film obtained by the conventional method. In addition, film formation was performed 10 times continuously under the same formation conditions as above, and the reproducibility of the film formation was investigated. The film obtained by the CVD apparatus of Reference Example 2 had a large relative dielectric constant and a large leak current density. While no variation was observed and the reproducibility was good, the film obtained by the conventional CVD apparatus showed a very large variation in both the relative dielectric constant and the leak current density with respect to the values shown in Table 2.

As in the case of Reference Example 1, when the apparatus was disassembled after the experiment and the inside of the reaction gas transport pipe and the inside of the vaporizer were examined, a large amount of gray granular products adhered to the conventional CVD apparatus. On the other hand, in the device of Reference Example 2 , this was hardly observed.

Example 1 FIG. 3 is a view showing the structure of an apparatus according to the present invention in which a vaporizer of another embodiment is incorporated in the CVD apparatus shown in FIG. 5 to 14 are the same as those in FIG. The inner wall surface of the vaporizer according to the present invention is covered with a coating layer 19 containing a polymerization inhibitor for preventing decomposition and polymerization of the raw material.

FIG. 5 is a view showing a cross section of the side wall of the vaporizer provided with the coating layer 19. In the figure, a coating layer 19 containing a decomposition and polymerization inhibitor of the raw material is provided on the inner surface 17 of the side wall of the vaporizer.

Examples of the polymerization inhibitor include metal powders such as silver, platinum, ruthenium, and osmium, alone or in combination, alkali agents such as sodium aluminate, potassium silicate, and sodium carbonate, or reducing agents such as sodium sulfite and ferrous sulfate. , Stannous chloride and the like are used.

The coating layer 19 is provided by uniformly mixing the polymerization inhibitor with a coating agent such as a silicone resin and applying the mixture to the inner surface 17.

The product adhering to the inner wall is a polymerization product of the raw material compound and the solvent, and the polymerization is promoted by an acidic substance or an oxidizing substance which is a reaction intermediate of the raw material compound or the solvent or a decomposition product. It is presumed to be.
It is considered that the polymerization inhibitor used acts on the above-mentioned acidic substance or oxidizing substance to eliminate the acidity or oxidizing property, thereby exhibiting a polymerization inhibiting action.

A vaporizer having such a coating layer may not be able to form an adhered product on its inner wall even during long-term use.
The evaporation state does not become unstable. Spouting of raw material solution,
Functions such as vaporization and formation of a thin film in the reaction furnace are the same as those in the case of Reference Example 1.

Incidentally, the coating layer may be provided on the inner wall of the reaction gas transport pipe to prevent deposits on the inner wall of the transport pipe.

[Experimental Example 3] SrTiO ₃ , which is a strontium titanate-based oxide dielectric film, was formed on a magnesium oxide substrate using the CVD apparatus having the above-described structure. However, the raw material system is binary, and the starting material is
A raw material obtained by dissolving acetylacetonate of Sr and Ti in tetrahydrofuran, which is an organic solvent, was used. The inner wall surface of the vaporizer was coated with a coating agent composed of a silicone resin containing silver and platinum powder at a ratio of 2: 1 and 20% by weight of the whole. Both raw material solutions were ejected and vaporized from a nozzle into a vaporizer by a liquid supply device. At this time, the temperature of the vaporizer was set at 210 ° C., the reaction gas was oxygen, the pressure in the reactor was 8 Torr, and the substrate temperature was maintained at 700 ° C., and the reaction was performed for 10 minutes. This step was repeated 30 times continuously.

For comparison, an oxide-based dielectric having the same composition was obtained by the same CVD apparatus as used in Comparative Example 1 using the same raw material solution and film forming conditions as described above and without coating the vaporizer. The film formation was repeated 30 times continuously in the same manner as when the apparatus of the present invention was used.

After the experiment, the apparatus was disassembled and the inside of the raw material gas transport pipe and the inside of the vaporizer were examined. In contrast to the conventional CVD apparatus having no coating on the inside, a large amount of white granular products adhered. This was not seen at all in vaporizers with a coating layer.

Example 2 FIG. 4 shows a CVD apparatus of FIG. 2 in which a vaporizer in which a coating layer 19 containing a polymerization inhibitor was provided on the inner wall surface of the vaporizer as described in Example 1 was incorporated. It is a device block diagram. FIG.
1 to 16 are the same as those shown in FIG.

[0067] In the CVD apparatus of the configuration of FIG. 4, a process to produce a thin film is the same as in Example 2.

[Experimental Example 4] Using a raw material system as a ternary material and using a CVD apparatus shown in FIG. 4 to form a ternary oxide-based dielectric film using dipivaloyl methanate of Pb, Zr and Ti as a starting material. Was done. The above-mentioned dipivaloyl methanates of Pb, Zr and Ti were respectively dissolved in tetrahydrofuran to obtain solutions of starting materials. The solution was sent to the vaporizer 13 while being atomized by the ultrasonic atomizer 16. At this time, 2 ml of tetrahydrofuran was used for 5 minutes using the solvent replenisher 15.
Into the raw material container 10. The optimum injection amount has been confirmed in advance by preliminary experiments. The temperature of the vaporizer 13 was set to 200 ° C., and argon was used as a carrier gas. The inner wall surface of the vaporizer 13 was coated with a vitreous frit containing sodium sulfite as a reducing agent and sodium aluminate as an alkaline agent in a ratio of 1: 1 and 15% by weight of the whole. Under the same conditions, vaporization was performed 5 times a day continuously.
Repeated 20 times a month.

For comparison, an oxide-based dielectric film having the same composition was formed by a CVD apparatus using the same raw material solution and not coating the vaporizer. Like the case where the apparatus of the present invention was used, it was used almost continuously for one month.

Further, as in the case of Experimental Example 3, the apparatus was disassembled after the experiment and the inside of the raw material gas transport pipe and the inside of the vaporizer were examined. While a large amount of the substance adhered, this was not seen at all in the CVD apparatus of the present invention.

Embodiment 3 FIG. 6 is a view showing one embodiment of a vaporizer used in the CVD apparatus of the present invention. The raw material solution supplied into the vaporizer adheres to a solid surface such as an inner wall of the vaporizer at a stage before vaporization,
Then evaporate. It is known that when the attached particles are vaporized, the specific surface area of the particles is a factor that affects the vaporization rate. Therefore, by increasing the adhesion area of the particles atomized by the vaporizing plate in the vaporizer, the fine particles are prevented from contacting each other and growing into particles having a larger specific surface area.

The vaporizer shown in FIG. 6 is used in the CVD apparatus having the structure shown in FIG. 1, and two sheets of the atomized raw material solution ejected from the nozzle 12 into the vaporizer 13 are provided as shown in FIG. The vaporizing plate 21 is attached to the inner surface of the vaporizer by the support rod 22 so that the interval becomes narrower from the nozzle 12 side toward the raw material gas transport pipe 5 side. By providing the vaporizing plate at an angle that obstructs the flow path, the atomized raw material solution hits the vaporizing plate 21 and adheres thereto and is vaporized.
By providing the vaporizing plate, vaporization of the atomized raw material solution becomes more uniform and further promoted.

The surfaces on the opposite sides of the two vaporizing plates 21 are provided with a coating 20 of a porous metal or a thermally conductive porous material such as silicon carbide, aluminum nitride or beryllium oxide. The vaporizing plate 21 itself is preferably made of stainless steel.

The vaporizer is heated by external heating means 14, for example, an electric furnace.

Incidentally, the inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

Experimental Example 5 The vaporizer in the CVD apparatus shown in FIG. 1 was replaced with the vaporizer shown in FIG. 6 (however, the inner surface of the vaporizer was coated with a ceramic porous body of aluminum nitride by plasma spraying) and used as a substrate. A strontium titanate-based oxide dielectric was formed on a silicon wafer by forming 300 nm thick SiO ₂ on a silicon wafer by thermal oxidation and further forming a 300 nm thick platinum electrode on the silicon wafer by sputter deposition. A film of SrTiO ₃ was formed. The conditions for film formation are the same as those in Reference Example 1, including the starting material, organic solvent, vaporizer temperature, reaction gas, pressure in the reaction section (furnace), and reaction film formation time. 1.6 of the obtained SrTiO ₃ thin film
The leakage current density when 5 V was applied was measured. Table 3 shows the results.

[Comparative Experimental Example 3] Using the same raw material solution and film forming conditions as described above, the same conventional CVD apparatus used in Comparative Experimental Example 1 was used to form an oxide dielectric film.
Performed 0 times. Similarly, this film has a thickness of 1.65 V
The leakage current density at the time of application was measured. Table 3 shows the results.

[0078]

[Table 3] As is clear from Table 3, when the vaporizer of the present invention is used, an excellent dielectric film having a good reproducibility of the film thickness and the leak current density, a high deposition rate, and a small leak current density can be obtained. It has been found.

In Experimental Example 5, a porous body of aluminum nitride formed by plasma spraying on a stainless steel plate was used as a vaporizing surface. However, a porous metal body, a sintered porous body of SiC or beryllium oxide may be used. A similar effect was obtained. When the porous body was formed of ceramics having poor thermal conductivity such as alumina, cordierite, and mullite, the above-mentioned remarkable effect was not obtained because the temperature uniformity in the vaporized surface was not sufficient.

In the third embodiment, the vaporizer is replaced with the C of the embodiment shown in FIG.
Although an example in which the present invention is applied to a VD apparatus has been described, it is also possible to apply the present invention to the CVD apparatus shown in FIG. 2 by replacing the nozzle 12 with a mere opening.

[Embodiment 4 ] FIG. 7 is a view showing the arrangement of another embodiment of the CVD apparatus according to the present invention (however, the source gas transport pipe 5 is omitted because it is the same as FIG. 1). 8 shows a vaporizer in the apparatus of FIG.

In FIG. 7 and FIG.
A plurality of inert gas transport pipes 2 are provided in the vaporizer 13 heated by
4 is open. The inert gas transport pipe 24 is heated by a heating means 25, for example, a heater. In the vaporizer, two opposing vaporizing plates 21 are attached to the inner wall of the vaporizer by support rods 22. It is preferable to use a stainless steel vaporizer.

The raw material solution is sent from the raw material container 10 to the nozzle 12 by the liquid supply means 11 through the liquid raw material transport pipe. Of the raw material liquids ejected from the nozzle 12 and atomized, those that cannot be immediately vaporized adhere to the vaporizing plate 21. On the other hand, the inert gas heated by the heater 25 is blown to the vaporization plate 21 through the heating gas transport pipe 24, thereby facilitating gasification of the raw material solution attached to the vaporization plate 21. The gasified raw material is sent to the raw material gas transport pipe 5.

As the inert gas, argon, helium and the like are preferably used.

Incidentally, the inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

Further, as described in the third embodiment, a coating of a porous metal body or a ceramic porous body having good heat conductivity may be applied to the surface on the opposite side of the vaporizing plate or the inner wall surface of the vaporizer.

[Experimental Examples 6 to 8] SrTiO _3, which is a strontium titanate-based oxide dielectric film, using the CVD apparatus of the present invention having the above-described structure.
Was formed on a magnesium oxide substrate. The starting materials and film forming conditions are almost the same as in Reference Example 1, except that the pressure in the reactor is set to 12 Torr and an inert gas blown to the vaporizing plate 21 is introduced in this embodiment. In this experimental example, the heating temperature of the heating inert gas was set to 220 ° C., and the flow rate of the heating inert gas was set to 0.5, 1.
The SrTiO ₃ film was obtained under the respective conditions by changing to 0 and 2.0 [l / min]. Note that argon gas was used as an inert gas. The obtained SrTiO ₃ film is changed to X
The crystallinity was investigated by line diffraction, and the dielectric constant and leak current density were measured.

Table 4 shows the characteristics of the film obtained by using the apparatus of the present invention and the film obtained in Experimental Example 1.

[0089]

[Table 4] When the vaporizer described in Example 4 was used, it was confirmed that the equivalent film thickness increased by 2% to 7%, but the leak current density was further improved. Regarding the dependence of the film characteristics on the flow rate of the heating gas in the present invention, the reproducibility was good even when the film was formed five times under the same conditions. This is because the heating gas flow rate is 1.0 [l
/ Min] is optimal.

In this experimental example, argon gas was used as the heating inert gas. However, the present invention is not limited to this. An inert gas such as helium or xenon can be expected to have the same effect as argon gas.

[Embodiment 5 ] FIG. 9 shows an embodiment of a vaporizer used in the CVD apparatus of the present invention having the apparatus configuration shown in FIG. This embodiment is characterized in that the outlet of the inert gas transport pipe 24 has a structure directed toward the outlet of the nozzle 12 in order to promote gasification of the raw material solution ejected from the nozzle. When the vaporizer of FIG. 9 is replaced with the vaporizer of the CVD apparatus shown in FIG. 7, the inert gas heated by the heater 25 passes through the inert gas transport pipe 24 and blows out from the nozzle 12 into the vaporizer 13 to be atomized. Gasification of the liquid raw material is facilitated by directly heating the atomized liquid particles that cannot be gasified among the raw materials.

In such an apparatus, it is possible to prevent the influence of local temperature decrease due to adiabatic expansion of the raw material solution generated near the nozzle outlet, and as a result, vaporization is easily and stably performed. The gasified raw material is sent to the raw material gas transport pipe 5.

Incidentally, the inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

[Experimental Examples 9 to 11] The vaporizer having the above-described configuration was subjected to the CVD shown in FIG.
SrTiO ₃ , which is a strontium titanate-based oxide dielectric film, was formed on a magnesium oxide substrate by applying to the apparatus. The starting materials and film forming conditions are almost the same as those in Experimental Example 1, but in this experimental example, the pressure in the reactor was set to 10 Torr.
This embodiment differs from Reference Example 1 in that an inert gas blown to the nozzle outlet is introduced. The film formation time was set to 7 minutes. In this experimental example, the heating temperature of the heating inert gas was 220 ° C., the flow rate of the heating inert gas was 0.5,
SrTiO ₃ changed to 1.0, 2.0 [l / min]
I got a membrane. However, argon gas was used as an inert gas. The dielectric constant of the obtained SrTiO ₃ film and the leak current density when a DC voltage of 1.65 V was applied were measured.

Table 5 shows the characteristics of the obtained SrTiO ₃ film and the characteristics of the film obtained in Experimental Example 1. As is clear from Table 5, the SrTiO ₃ film obtained by the CVD apparatus having the vaporizer of Example 5 has a clearly improved leak current characteristic as compared with the film using the conventional vaporizer. The converted film thickness, which is one of the dielectric constant characteristics, is about 3.5% of that of a film formed by a conventional vaporizer in a film formed under the condition that the heating gas flow rate is 2.0 [l / min]. large. This is considered to be the result of the relative dielectric constant decreasing as the film thickness decreases. Regarding the reproducibility of the film, it was confirmed that film formation was performed three times under each condition, and that substantially the same characteristics were obtained.

[0096]

[Table 5] In the present embodiment, an example is shown in which two heated gas outlets are provided and installed so as to face each other.
When two or more outlets are provided, the same effect as in the present embodiment can be expected even when the outlets are symmetrically installed and the same flow rate of the inert gas is supplied to each.

[Embodiment 6 ] As one method of heating the vaporizer used in the CVD apparatus of the present invention, a heating medium such as oil may be circulated outside the vaporizer. With this method, the vaporizer can be heated at a stable temperature.

In FIG. 10, a vaporizer heating medium 27 in a heating medium container 26 is heated by a heating means 31 such as a heater and sent to a heating section 29 around the vaporizer through a heating medium transport pipe 28. Heating the vaporizer 13;
The heating medium is returned to the heating medium container 26 again by the circulation pump 30, and is again heated and circulated.

The outer peripheries of the passages 28 and 29 through which the heating medium passes are surrounded by a heat insulating material (not shown) for keeping the temperature.

The solution of the raw material used for CVD is ejected from the nozzle 12 through the raw material solution transport pipe 23 to be atomized, vaporized by the heat in the vaporizer, and sent to the raw gas transport pipe 5.

As the heating medium, oils, especially methyl silicone oil, ethyl silicone oil, phenyl silicone oil and the like are preferable in view of various properties.

The inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

Further, a vaporizing plate shown in FIG. 6 may be provided inside the vaporizer.

Further, a coating of a porous metal body or a porous ceramic body having good heat conductivity may be applied to the surface on the opposite side of the vaporizing plate.

[0105] As shown in FIG.
The main body of the vaporizer 13 and the outside of the heating unit 29 can be made of a transparent heat-resistant hard glass 32. In such a device, since the inside of the vaporizer can be seen through, it is easy to find out when a raw material polymer or the like adheres to the inside of the vaporizer, which is convenient for maintenance.

In the sixth embodiment, the vaporizer is replaced with the C of the embodiment shown in FIG.
An example in which the present invention is applied to a VD apparatus has been described. However, the present invention can be applied to an apparatus having an embodiment as shown in FIG. 7, or can be applied to a CVD apparatus having the embodiment shown in FIG. is there.

[Experimental Example 12] An experiment in which the vaporizer having the structure shown in FIG. 10 was applied to the CVD apparatus in Reference Example 1 and SrTiO ₃ , which is a strontium titanate-based oxide derivative film, was formed on a magnesium oxide substrate. went. The starting materials are the same as in Experimental Example 1. Further, the transport amount of the raw material solution and the film forming conditions in the reaction furnace are the same as those in Experimental Example 1. The oil was heated in the vaporizer so that the temperature was maintained at 210 ° C. After the reaction, the mixture was naturally cooled in a furnace to room temperature in an oxygen stream. The dielectric constant of the obtained SrTiO ₃ film and the leak current density when a DC voltage of 1.65 V was applied were measured.

[Experimental Example 13] Platinum was sputter-deposited in the same manner as in Experimental Example 12 by using a vaporizer having the structure shown in FIG. 11 in which the vaporizer main body in Experimental Example 12 was changed to one using transparent heat-resistant hard glass. An experiment was conducted in which a SrTiO ₃ foil film was formed on the thus-formed silicon substrate. As a result of processing under the same conditions as in Experimental Example 5, an oxide dielectric thin film having a thickness of 50 to 60 nm was obtained.
The dielectric constant of the obtained thin film and the leak current density when a DC voltage of 1.65 V was applied were measured.

As a preliminary experiment, without supplying raw materials,
The temperature distribution in the vaporizer was measured with a thermocouple. When the oil temperature in the vaporizer in FIG. 11 was 220 ° C., the temperature distribution in the vaporizer was 217 ± 2 ° C., and a uniform temperature distribution was obtained.

[Comparative Experimental Example 4] Using the same raw material solution as above, an SrTiO ₃ film was provided on a silicon substrate on which platinum sputter deposition was performed under the same conditions as in Experimental Example 13 using a conventional CVD apparatus.

Table 6 shows the results of the films obtained in Experimental Examples 12 and 13 and Comparative Experimental Example 4.

[0112]

[Table 6] As is clear from Table 6, the characteristics of the SrTiO ₃ film obtained by the CVD apparatus using the vaporizer described in Example 6 are lower in both the reduced film thickness and the leak current density than the film using the conventional vaporizer. It has become much smaller. When film formation was performed five times under the same film formation conditions as above, almost the same characteristics were obtained for these films. After the experiment, when the apparatus of Experimental Example 12 was disassembled, no deposits were found in the vaporizer or the raw material gas transport pipe.

In the vaporizer of Experimental Example 13, it was visually confirmed from the outside that there was no extraneous matter in the vaporizer, and it was confirmed that the reaction gas transport pipe was decomposed and free of extraneous matter.

Embodiment 7 FIG. 12 shows one embodiment of the inner wall of a vaporizer used in the CVD apparatus of the present invention.

In FIG. 12, the inner wall surface 17 of the vaporizer 13 is
Of the raw material solution ejected from the nozzle 12 and atomized, the liquid which is not immediately vaporized adheres to the inner wall surface having the irregularities and is vaporized. By providing the unevenness, the vaporization area is increased, and the vaporization efficiency is promoted.

Although the mounting position of the source gas transport pipe 5 is not particularly limited, it is preferable to mount it in a direction perpendicular to the direction of the jet nozzle 12 as shown in FIG. However, it is not limited to the embodiment of FIG.

Although the external heating means of the vaporizer is not shown in FIG. 12, even if a heating heater as in the case of the structure of Reference Example 1 is used, the heating medium is circulated as shown in Embodiment 6. A method may be used.

When the thermal conductivity of the vaporizer material is poor, a temperature difference may occur between the irregularities on the inner wall surface and the heating means. In such a case, the heating temperature is set to be high. The temperature of the inner wall may be controlled so as to be a desired vaporization temperature.

Incidentally, the inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

Further, a vaporizing plate shown in FIG. 6 may be provided inside the vaporizer.

Further, a coating of a porous metal body or a porous ceramic body having good thermal conductivity may be applied to the surface on the opposite side of the vaporizing plate.

In the seventh embodiment, the vaporizer is replaced with the C of FIG.
Although an example in which the present invention is applied to a VD apparatus has been described, it is also possible to apply the present invention to the CVD apparatus shown in FIG.

Embodiment 8 FIG. 13 shows Embodiment 3 of a vaporizer used in the CVD apparatus of the present invention.
FIG. 6 is a view showing another embodiment of the vaporizing plate described in FIG. Vaporizer 1
The vaporizing plate 2 having an internal heater 36 on the inner wall surface 17
1 projects perpendicularly to the wall surface toward the center of the vaporizer 13 so as to obstruct the particle path of the solution of the atomized raw material ejected from the nozzle, and the entire wall surface of the vaporizer 13 and the entire surface of the internal heater 36. Is the vaporization side. The raw material sent in a liquid state is jetted into the vaporizer 13 by the nozzle 12 and is vaporized by colliding with the vaporizing plate 21 heated by the internal heater 36. Therefore, most of the calorific value of the internal heater 36 is used for vaporizing the raw material and heating the air inside the vaporizer, so that the raw material can be efficiently vaporized with low power.

Incidentally, the inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

Note that the inner wall surface of the above-described apparatus was used in Example 7 (FIG. 1).
It is also effective to have irregularities as described in 0).

Although the external heating means of the vaporizer is not shown in FIG. 13, even if a heater as in the case of the configuration of FIG. 1 is used, a method of circulating a heating medium as shown in FIG. May be used.

The inner wall of the vaporizer and / or the surface of the vaporizer may be coated with a porous metal or a porous ceramic having good thermal conductivity.

In Example 8 , the carburetor was replaced by the C of the embodiment shown in FIG.
An example in which the present invention is applied to a VD apparatus has been described. However, the present invention may be applied to the apparatus configuration shown in FIG. 7, or may be applied to the CVD apparatus shown in FIG. 2 by replacing the nozzle 12 with a mere opening.

[Embodiment 9 ] FIG. 14 is a configuration diagram showing still another example of the vaporizer used in the CVD apparatus of the present invention. 5 and 12 are Reference Examples 1
Is the same as A filter 42 is provided on the outlet side of the vaporizer 13. The filter 42 is a vaporizer 1
The mist-like raw material solution that has not been vaporized in the inside 3 is captured and acts to prevent it from being sent to the reaction gas transport pipe 5.

The material of the filter 42 is preferably a mesh-shaped sintered metal, a powdered sintered metal, a reticulated metal, a three-dimensional reticulated porous metal, or the like, and the pore diameter is preferably about 0.5 μm.

The raw material solution ejected from the nozzle 12 is atomized and vaporized. However, as a result of being trapped by the non-vaporized solution or the filter 42 which adversely affects the uniformity and characteristics of the obtained film, almost all of the raw material solution remains in the reaction furnace. Only completely vaporized raw material is sent, and as a result, highly accurate film thickness control is possible.

The inner surface of the vaporizer in FIG. 14 is an embodiment.
Irregularities such as 7 may be provided.

Although the external heating means of the vaporizer is not shown in FIG. 14, even if a heating heater as in the case of the configuration of FIG. 1 is used, a method of circulating a heating medium as shown in FIG. May be used.

The inner wall surface of the vaporizer of the above embodiment may be coated with a layer containing a polymerization inhibitor as in the first embodiment.

Further, a vaporizing plate having an internal heater as in Embodiment 8 is provided inside the vaporizer, or FIGS.
May be provided, and the inner wall and / or the surface of the vaporizer may be coated with a porous metal or a porous ceramic having good thermal conductivity.

In the ninth embodiment, the carburetor is the same as that of the embodiment shown in FIG.
Although an example in which the present invention is applied to a VD apparatus has been described, it is also possible to apply the apparatus shown in FIG. 6 or the apparatus CVD apparatus shown in FIG. 2 by replacing the nozzle 12 with a mere opening.

In the vaporizer of FIG. 14, the vaporizer 1
The heating means 3 may be an oil heating method as shown in FIG. 11, and the outside of the vaporizer main body and the heating section 29 may be made of transparent heat-resistant hard glass. In such a device, since the inside of the vaporizer can be seen through, it is easy to find out when a raw material polymer or the like adheres to the inside of the vaporizer, which is convenient for maintenance.

The material of the vaporizer is not particularly limited, but a transparent material such as hard glass or a material having good heat conductivity such as aluminum is preferably used. When a transparent material is used, it is easy to monitor the inside and maintenance is easy. When a material having good heat conductivity is used, the inner wall of the vaporizer may be covered with a metal porous body or a ceramic porous body made of a material having good heat conductivity such as SiC, BeO, or AlN.

In this embodiment, the case of the apparatus configuration of FIG. 1 has been described. However, FIG. 6 or the vaporizer of the apparatus configuration of FIG. 2 can be used by replacing the nozzle 12 with a mere opening.

Further, a vaporizing plate shown in FIG. 7 may be provided inside the vaporizer.

[Embodiment 10 ] As a vaporizer used in the CVD apparatus of the present invention, FIG.
As shown in (1), a material having a coating 41 made of a material having low surface energy and high heat resistance on its inner wall surface can be used. As the coating material, for example, a fluororesin known as Teflon under the trade name is preferably used. When a metal having good heat conductivity such as silver is mixed with the fluororesin in an amount of about 20 to 40% by volume,
Further, the vaporization property is improved.

FIG. 15 shows a method using a heating oil as described in Embodiment 6 as a heating means for the vaporizer 13, but a means such as an external heater as described in Reference Example 1 may be used.

In the vaporizer having the coated inner wall surface, deposition particles are prevented from adhering to the inner wall surface.

[0144] Note that the inner wall surface in order to promote the vaporization of the atomized source solution, may be attached to the vaporizing plate as described in Example 3 or 8, also the inner wall surface as described in Example 7 Irregularities may be provided.

The vaporizer can be incorporated in any one of the configurations shown in FIGS. 1, 2 and 7.

[Examples 14 to 17] In Example 14, a vaporizer having irregularities on the inner wall surface described in Example 7 was used as a vaporizer in the CVD apparatus of Reference Example 1 (FIG. 12; In Experimental Example 15, a vaporizer provided with a vaporizing plate having an internal heater described in Example 8 (FIG. 13; however, an external heating method was the same as in Experimental Example 14 in which heating was performed from the surroundings with a heater). In Experimental Example 16, the filter described in Example 9 and having a filter between the vaporizer and the raw material gas transport pipe (FIG. 14) was used.

As the filter, a 0.5 μm mesh nickel-chromium alloy sintered metal filter was used. Further, in Experimental Example 17, a vaporizer in which the inside of the vaporizer was coated with a fluororesin was used.

Using the above-mentioned CVD apparatus, acetylacetonate of titanium and strontium was used as a raw material, and a film of SrTiO ₃ was formed on a silicon substrate on which platinum was deposited by sputtering.

The conditions of the experiment are the same as those of the fifth embodiment. As a result, an oxide dielectric film having a thickness of about 50 to 60 nm was obtained.
The crystallinity is investigated by X-ray diffraction, and the dielectric constant and DC voltage
The leakage current density when applying 1.65 V was measured.

Table 7 shows the results of Comparative Examples 4 to 17 obtained in Examples 14 to 17 and Example 6 . The crystallinity of the thin film obtained in Comparative Experimental Example 4 was also measured by X-ray diffraction.

[0151]

[Table 7] As is clear from Table 7, according to the apparatus using the vaporizer, it is possible to form a dielectric thin film having better performance by the CVD method than when using the conventional CVD apparatus. In particular, the leak current was able to be suppressed to 1/10 or less as compared with the film obtained by the conventional method. In addition, film formation was performed 10 times continuously under the same film formation conditions as described above, and the production reproducibility of the film was examined. No reproducibility was found, indicating that the reproducibility was good. On the other hand, in the film obtained in Comparative Experimental Example 4, the relative dielectric constant and the leak current density showed extremely large variations with respect to the values shown in Table 7.

After the experiment, when the apparatus was disassembled and the inside of the vaporizer and the inside of the transport pipe were examined, in Examples 14 to 17, almost no white granular product was observed, and the particulate product was captured on the filter. I have been admitted. On the other hand, in Comparative Experimental Example 4, this was attached in a large amount.

[Experimental Example 18] In order to further confirm the effects of the vaporizers of Examples 9 and 10 , a raw material solution containing 20% of a degraded raw material (dissolved in a solvent but not vaporizable) was intentionally mixed. Experimental Example 1
Vaporization was performed under the same conditions as in Examples 6 and 17, and a conventional vaporizer was used for comparison.

After the experiment was completed, a considerable amount of particulate matter was found in the vaporizer and the filter in the vaporizer of Example 9 , but hardly any solid matter was found in the raw material gas transport pipe.

In the vaporizer of Example 10 , a small amount of deposits was observed in the vaporizer. On the other hand, in the case of using the conventional vaporizer, an extremely large amount of deposits was observed not only in the vaporizer but also in the raw material gas transport pipe.

[0156]

By using the CVD apparatus of the present invention, a source gas having a uniform concentration can be obtained, and a uniform thin film can be obtained by a CVD method in a reactor.

When a vaporizer having a vaporizing plate is used in the CVD apparatus of the present invention, the atomized raw material solution is easily vaporized, a uniform raw material gas is obtained, and a thin film having good performance is obtained.

Further, in the CVD apparatus of the present invention, a heated carrier gas blow-out pipe opened toward the atomized raw material solution ejected from the nozzle immediately before the nozzle for atomizing and ejecting the material solution is provided. When a vaporizer having the same is used, the atomized raw material solution ejected from the nozzle is uniformly vaporized, a raw material gas having a uniform concentration is obtained, and a thin film with good performance is obtained.

Further, in the CVD apparatus of the present invention, when the heated carrier gas blow-out tube uses a vaporizer having a structure in which a gas is blown out toward the inner wall surface and / or the vaporizing plate of the vaporizer, the raw material can be obtained as follows. The solution is easily vaporized, and a raw material gas having a uniform concentration is obtained, and a thin film having good performance is obtained.

Further, in the CVD apparatus of the present invention, when a raw material container for atomizing the raw material solution by ultrasonic waves is used in advance, the vaporization in the vaporizer occurs uniformly, and the raw material gas having a uniform concentration is obtained, and the performance is good. A thin film is obtained.

Further, by using a means for supplying a solvent to the raw material solution stored in the raw material container, the concentration of the raw material solution in the raw material container can always be kept constant.

Further, in the CVD apparatus of the present invention, if a vaporizer in which the inner wall of the vaporizer is coated with a layer containing a material for preventing polymerization of the raw material solution is used, the adhesion of the polymer can be prevented. A uniform source gas can be obtained over a long period of time, and a thin film having good performance can be obtained.

In the CVD apparatus of the present invention, when a vaporizer having an uneven inner wall surface is used, vaporization is facilitated and uniform raw material gas is generated, so that a thin film having good performance can be obtained. .

Further, in the CVD apparatus of the present invention, if a vaporizer that heats by circulating hot oil in the surrounding heating section is used, a uniform raw material gas is generated, so that a thin film having good performance can be obtained.

Further, in the CVD apparatus of the present invention, if the outside of the vaporizer main body and the heating section is made of a transparent material, the inside can be visualized, and the maintainability is improved.

In the CVD apparatus of the present invention, if a filter having fine holes is provided between the vaporizer and the raw material gas transport pipe, the unvaporized raw material and the fine powder generated in the vaporizer react. It is possible to prevent the reactor from being sent to the furnace, prevent the reactor from being contaminated, and obtain a thin film having good performance.

Further, in the CVD apparatus of the present invention, if the vaporizer having the inner wall surface having a low surface activity is used, the unvaporized raw material is prevented from adhering to the inner wall of the vaporizer and uniform raw material gas is generated, so that the performance is good. A thin film is obtained.

[Brief description of the drawings]

FIG. FIG. 2 is an apparatus configuration diagram showing a reference example of a CVD apparatus.

FIG. 2 FIG. 2 is an apparatus configuration diagram showing a reference example of a CVD apparatus.

FIG. 3 is an apparatus configuration diagram showing a CVD apparatus of the present invention.

FIG. 4 is an apparatus configuration diagram showing a CVD apparatus of the present invention.

FIG. 5 is a diagram showing a cross section of a side wall of a vaporizer used in the CVD apparatus of the present invention.

FIG. 6 is a diagram showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 7 is an apparatus configuration diagram showing a CVD apparatus of the present invention.

FIG. 8 is a diagram showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 9 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 10 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 11 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 12 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 13 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 14 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 15 is a view showing an embodiment of a vaporizer used in the CVD apparatus of the present invention.

FIG. 16 is an apparatus configuration diagram showing a conventional CVD apparatus.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideko Uchikawa 8-1-1, Tsukaguchi Honcho, Amagasaki City Inside Mitsubishi Materials Corporation Materials and Devices Laboratory (72) Inventor Hisao Watoi 8-1-1, Tsukaguchi Honmachi, Amagasaki City No. Mitsubishi Materials Corporation Materials and Devices Research Laboratories (72) Inventor Shigeru Matsuno 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Materials Corporation Materials and Devices Research Laboratories (72) Inventor Shinichi Kinouchi 8-1-1 Tsukaguchi Honcho Amagasaki City No. 1 Mitsubishi Electric Corporation Materials and Devices Research Laboratories (72) Yasuji Matsui 8-1-1, Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor Akimasa Yuki 8 Tsukaguchi Honmachi Amagasaki City Central 1-1, Mitsubishi Electric Corporation (72) Inventor Takaaki Kawahara 8-1-1, Tsukaguchi Honcho, Amagasaki City No. Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor Akira Nishimoto 4-1-1 Mizuhara Itami City Mitsubishi Electric Corporation In the Kita Itami Works (72) Inventor Koichiro Tsutahara 4-1-1 Mizuhara Itami City Mitsubishi Electric Corporation Inside Kita Itami Works (72) Inventor Takashi Higaki 4-1-1 Mizuhara, Itami City Mitsubishi Electric Corporation LSE Research Institute (72) Inventor Tomohito Okuhira 4-1-1 Mizuhara Itami City Mitsubishi Electric Corporation・ Within the Institute for Eye Research (72) Inventor Keiichiro Kashiwara 4-1-1 Mizuhara, Itami City Mitsubishi Electric Corp. Inside the LSI Research Institute (72) Inventor Taizo Ejima 1-1-1, Imajukuhigashi, Nishi-ku, Fukuoka City Mitsubishi Electric (56) References JP-A-2-22106 (JP, A) JP-A-3-126872 (JP, A) JP-A-3-8330 (JP, A) (58) Fields surveyed ( Int.Cl. ⁷ , DB name) H01L 21/205 B01J 12/00 C23C 16/44

Claims (15)

(57) [Claims] 1. A raw material container for containing a raw material solution, means for preliminarily atomizing the raw material solution, and the atomized raw material
An inlet tube for supplying the solution, supplied from the inlet tube
A vaporizer for vaporizing by heating the atomized raw material solution, comprising a reactor having a heating means of the raw material gas transport pipe for transporting the vaporized source gas, and the raw material gas introduced from the raw material gas transport tube It becomes Te, the vaporizer is the atomized is supplied from the inlet tube
In the course of the flow of the raw material solution to the raw material gas transport pipe,
Block or obstruct the flow path of the atomized material solution
One or two or more vaporizers provided at a staggered angle
A liquid material CVD apparatus having a plate. 2. A raw material container for containing a raw material solution,
Means for atomizing the raw material solution in advance, the atomized raw material
An inlet tube for supplying the solution, supplied from the inlet tube
Vaporizing the atomized raw material solution by heating
Vessel, a source gas transport pipe for transporting the vaporized source gas, and
And means for heating the source gas introduced from the source gas transport pipe.
Comprising a reactor having a step, The vaporizer is a heated carrier gas outlet pipe;
A liquid material CVD apparatus comprising: 3. A raw material container for containing a raw material solution,
Means for atomizing the raw material solution in advance, the atomized raw material
An inlet tube for supplying the solution, supplied from the inlet tube
Vaporizing the atomized raw material solution by heating
Vessel, a source gas transport pipe for transporting the vaporized source gas, and
And means for heating the source gas introduced from the source gas transport pipe.
Comprising a reactor having a step, The vaporizer is configured to perform the atomization supplied from the introduction pipe.
In the course of the flow of the raw material solution to the raw material gas transport pipe,
Block or obstruct the flow path of the atomized material solution
One or two or more vaporizers provided at a staggered angle
Blowout of heated carrier gas with plate
A liquid material CVD apparatus having a tube. 4. The blowing of the heated carrier gas.
The atomization pipe is supplied from the introduction pipe into the vaporizer.
3. The method according to claim 2, wherein the material is open toward the raw material solution.
4. The liquid source CVD apparatus according to 3. 5. A raw material container for containing a raw material solution,
Liquid supply means for supplying a raw material solution, the liquid supply means
The raw material solution supplied by the step is vaporized by heating
Vaporizer, source gas transportation for transporting the vaporized source gas
Pipe, and the source gas introduced from the source gas transport pipe.
Comprising a reactor having heating means, The vaporizer is a nozzle for atomizing and introducing the raw material solution.
Heating means for vaporizing the atomized raw material solution,
The above-mentioned source gas transfer of the source solution sprayed and atomized from the nozzle
In the middle of the flow path to the feed pipe, the flow of the
Vertical or at an angle that obstructs the flow path
For liquid raw material, comprising C or two or more vaporizing plates
VD device. 6. A raw material container for containing a raw material solution,
Liquid supply means for supplying a raw material solution, the liquid supply means
The raw material solution supplied by the step is vaporized by heating
Vaporizer, source gas transportation for transporting the vaporized source gas
Pipe, and the source gas introduced from the source gas transport pipe.
Comprising a reactor having heating means, The vaporizer is a nozzle for atomizing and introducing the raw material solution.
Heating means for vaporizing the atomized raw material solution,
Having a heated carrier gas outlet tube
Liquid source CVD equipment. 7. A raw material container for containing a raw material solution,
Liquid supply means for supplying a raw material solution, the liquid supply means
The raw material solution supplied by the step is vaporized by heating
Vaporizer, source gas transportation for transporting the vaporized source gas
Pipe, and the source gas introduced from the source gas transport pipe.
Comprising a reactor having heating means, The vaporizer is a nozzle for atomizing and introducing the raw material solution.
Heating means for vaporizing the atomized raw material solution,
The above-mentioned source gas transfer of the source solution sprayed and atomized from the nozzle
In the middle of the flow path to the feed pipe, the flow of the
Vertical or at an angle that obstructs the flow path
One or more vaporizers and a heated carrier
And a liquid source CVD apparatus having a gas outlet pipe. 8. Blowing of the heated carrier gas
The pipe is the nozzle To the atomized raw material solution
The liquid material according to claim 6 or 7, wherein the liquid material is opened.
CVD equipment. Blown <br/> and tube wherein said heated carrier gas, a structure for ejecting the vaporizer wall and (or) gas toward the vaporizing plate provided inside the vaporizer according Item 1, 2, 3, 4, 5, 6, 7 or 8
Liquid source CVD equipment. 10. inner wall of the evaporator becomes coated with a layer containing a material to prevent polymerization of the raw material solution according to claim
Liquid source according to 1, 2, 3, 4, 5, 6, 7, 8 or 9
CVD equipment for materials. 11. The liquid material according to claim 10 , wherein the material for preventing polymerization comprises a metal powder, an alkali agent or a reducing agent.
CVD equipment for materials. 12. The inner wall surface of the vaporizer and / or
The vaporization plate whose surface is covered with a porous body made of a material having good thermal conductivity .
12. The CVD apparatus for a liquid raw material according to 9, 10, or 11. 13. The method according to claim 1, wherein the inner wall surface of the vaporizer has an uneven surface .
The CVD apparatus for a liquid raw material according to 9, 10, 11 or 12
Place. 14. A claim that the filter is provided with pores between said vaporizer and said source gas transport pipe
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 1
14. The liquid raw material CVD apparatus according to 2 or 13. The inner wall surface according to claim 14, wherein the vaporizer, the surface activity is low, and those coated with a material having high heat resistance according
Terms 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
15. The liquid material CVD apparatus according to 12, 13, or 14.