JPH0794426A - Cvd device - Google Patents

Abstract

PURPOSE:To uniformly form a high-quality thin film by preventing the deposition and clogging of particles in a raw material container and pipeline and concentration graduation of a solution raw material while the solution raw material is vaporized and the thin film is formed. CONSTITUTION:A solution raw material is supplied in a liquid state from a raw material container 10 and the solution raw material is vaporized by jetting the solution raw material in a vaporizer after atomizing the raw material in a diluted gas flow at the front end of a nozzle 12. The vaporized gas is sent to a reaction chamber 6 for forming a thin film.

Description

Detailed Description of the Invention

[0001]

This invention relates to chemical vapor deposition Ch
C for forming various thin films by an electronic vapor deposition (hereinafter referred to as CVD) method
The present invention relates to a VD apparatus, and more particularly to a CVD apparatus for liquid raw material.

[0002]

2. Description of the Related Art In recent years, high-density integration of semiconductor devices has been rapidly progressing, and semiconductor memory, for example, dynamic random access memory (hereinafter referred to as DRAM).
For the purpose of increasing the device speed, reducing the power consumption, and reducing the cost, the degree of integration is improving at a rapid pace with the number of bits being quadrupled in three years. However, the capacitor, which is a constituent element of the DRAM, must maintain a certain capacity even if the degree of integration is improved. Therefore, it is necessary to reduce the film thickness of the capacitor material. Therefore, the silicon oxide film (SiO
_{In the case of 2} films), there was a limit to the thinning, and alternative capacitor materials with high dielectric constants were required.

The performance required for such a capacitor material is that it is a thin film having a high dielectric constant and a small leak current. Generally Si
O2 _conversion 1nm or less SanmakuAtsu, and, there is a 10 ^-8 A / cm ² order or less is desirable in the leakage current density at 1.65V applied. From this point of view, tantalum oxide,
Oxide-based dielectric films such as lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), strontium titanate, and barium titanate have been investigated using various film forming methods.

Generally, in order to form a dielectric film as a thin film on a capacitor electrode of a DRAM having a step, it is advantageous in terms of a process to use a CVD method which has good throwing power to an object having a complicated shape. is there. However, the vaporization characteristics of a β-diketone-based divivaloylmethane (DPM) compound, which is widely used as a CVD raw material when forming the above-mentioned oxide-based dielectric film having a high dielectric constant and a small leak current, by heating. Had the problem of not being good.

Therefore, recently, Japanese Patent Application No. 4-252536
As shown in No. "CVD raw material for oxide-based dielectric thin film",
By dissolving an organic metal compound such as a β-diketone-based DPM compound, which is a conventional solid material, in an organic solvent called tetrahydrofuran (THF) to form a solution, a CVD material having dramatically improved vaporization property has been developed. It was

FIG. 9 shows the most common conventional CV for liquid raw material.
It is a schematic diagram which shows the outline of a structure of D apparatus. Details of such an apparatus are described in, for example, Chemical Engineering, CVD Handbook 2
26, 227 (published by Asakura Shoten in 1991). In the figure, 1 is a diluting gas pipe for supplying diluting gas such as argon, 2 is a diluting gas supplier, 3 is a bubbler which also serves as a raw material container and vaporizer, 4 is a heater for heating the bubbler 3, 5 is a raw material gas transport pipe, 6 is a reaction chamber, 7 is a heating mechanism, 8 is a substrate to be processed (hereinafter referred to as a substrate) such as a silicon wafer, and 9 is a reaction gas transport pipe.

Next, the operation will be described. The bubbler 3 containing the liquid raw material is heated to a predetermined temperature by the heater 4,
When the diluent gas is supplied into the liquid raw material by the diluent gas supplier 2, a part of the liquid raw material is vaporized by bubbling in the liquid raw material in the bubbler 3, and the raw material corresponding to the saturated vapor pressure at a predetermined temperature is obtained. The gas is supplied to the reaction chamber 6 through the raw material gas transport pipe 5 together with the diluent gas. The raw material gas supplied to the reaction chamber 6 reacts with an oxidant such as oxygen supplied from the reaction gas transport pipe 9 to the reaction chamber 6 in the vicinity of the surface of the substrate 8 which has been preheated, thereby forming a thin film on the substrate 8. Deposit.

[0008]

Conventional CV for liquid raw material
Since the D device is configured as described above, when a CVD raw material which is a solution of an organometallic compound developed in recent years is used, the solid raw material is a raw material which is a solution of the organic solvent THF. The vaporization of the raw material caused by heating and bubbling is mainly the vaporization of the organic solvent. For this reason, the concentration of the solution raw material increases with time, and the vaporized state also changes accordingly, resulting in increased inhomogeneity such as compositional deviation of the formed thin film, and as a dielectric film for a capacitor, The leak current was increased. In addition, there is a problem that a powdery precipitate is generated or clogging occurs on the wall surface inside the bubbler 3 and the inner wall of the raw material gas transport pipe 5 due to the change over time of the solution raw material during film formation.

Such a problem occurs not only in the case of the CVD raw material as described above, but also in the case of a liquid raw material composed of two or more kinds of materials having different vapor pressures. Further, even a single liquid raw material is heated and kept warm in the bubbler 3 for a long time, so that there is a problem that the liquid raw material gas is gradually decomposed or deteriorated.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to prevent changes in the solution concentration of the liquid raw material and other alterations and deteriorations during vaporization and film formation of the liquid raw material. Prevents particle precipitation and clogging in the raw material container and piping, and there is no composition shift,
An object of the present invention is to provide a liquid source CVD apparatus capable of forming a uniform and high-quality thin film.

[0011]

A CVD apparatus according to claim 1 of the present invention comprises a raw material container for containing a liquid raw material, a liquid raw material supply device for taking out the liquid raw material from the raw material container, and a liquid raw material supply device. The liquid raw material and the diluent gas are supplied, and the liquid raw material is atomized and ejected, and a vaporizer for vaporizing the atomized liquid raw material.

A CVD apparatus according to a second aspect of the present invention is
A liquid raw material sent from a liquid raw material supply device is supplied to a vaporizer by a nozzle, a diluting gas passage is provided on the outer periphery of the nozzle, and the tip of the nozzle is positioned at the narrowed portion of the passage.

A CVD apparatus according to claim 3 of the present invention is
A bypass pipe line provided with an on-off valve that connects a pipe for supplying a liquid raw material from a feeder to a vaporizer and a raw material container is provided.

A CVD apparatus according to claim 4 of the present invention is
The return tank is decompressed, and the pipe for supplying the liquid raw material supply device to the vaporizer is connected to the above-mentioned return tank by a discharge pipe having an on-off valve.

A CVD apparatus according to claim 5 of the present invention is
It is provided with a plurality of raw material containers for individually storing a plurality of types of liquid raw materials.

A CVD apparatus according to claim 6 of the present invention is
After the film formation, the ejection port for ejecting the solution constituting the liquid raw material to the vaporizer, and its peripheral piping are provided with a solvent by a solvent supply pipe and a solvent tank for cleaning, and thereafter, a means for discarding the solvent is provided. It is a thing.

A CVD apparatus according to claim 7 of the present invention is
A means for supplying the solvent vapor of the solution forming the liquid raw material is provided in the diluent gas flow path to be supplied to the vaporizer.

The CVD apparatus according to claim 8 of the present invention is
The vaporizer and the reaction chamber have a continuous structure in which the internal spaces are directly communicated with each other.

A CVD apparatus according to claim 9 of the present invention is
The raw material container or the pipe from the raw material container to the vaporizer, or the flow path of the vaporized raw material gas is provided with a raw material property analyzing means having a light emitting element and a photodetector.

[0020]

In the CVD apparatus according to the present invention, the raw material container and the vaporizer are separately configured, and the required amount of liquid is supplied to the vaporizer by the liquid raw material supply device and vaporized there. Therefore, unlike the conventional apparatus in which the liquid material is vaporized and supplied in a gas state, the liquid material is not altered or deteriorated and the concentration is kept constant. Therefore, particle precipitation and clogging in the raw material container and the piping system are prevented,
It is possible to form a uniform and high quality thin film with no composition shift. Further, when the liquid raw material is supplied to the vaporizer, the atomizing liquid raw material is heated and easily vaporized in the vaporizer while being mixed with the diluent gas because the atomizing liquid atom is ejected by using the diluent gas. . In this way, efficient vaporization with little vaporization residue is possible in the vaporizer.

Further, the liquid raw material is supplied to the vaporizer by a nozzle, a diluting gas passage is provided on the outer periphery of the nozzle, and the tip of the nozzle is positioned at the narrowed portion of the passage. That is, the liquid raw material is supplied from the tip of the nozzle in the state of being surrounded by the diluent gas at the throttle portion where the flow velocity of the supplied diluent gas is maximum. Therefore, the liquid raw material is efficiently atomized by the surrounding dilution gas and ejected into the vaporizer.

Further, a bypass pipe line provided with an on-off valve is provided, which connects the pipe for supplying the liquid raw material supply device to the vaporizer to the raw material container. As a result, after the film formation, the liquid raw material remaining in the jet port to the vaporizer and the peripheral pipe thereof returns to the raw material container, so that it is not solidified or clogged in the jet port or the narrow tube.

In addition, a depressurized return tank is provided,
Since the return raw material is returned to the return tank by the discharge pipe instead of the raw material container, the liquid raw material in the raw material container is not affected even if the return raw material is altered.

Since a plurality of raw material containers for individually storing a plurality of types of liquid raw materials are provided, even mixed raw materials composed of a plurality of types of liquids having different vapor pressures are separately supplied from different raw material containers. The amount can be controlled and supplied, the liquid raw material in the raw material container is not deteriorated, and a uniform thin film can be formed with good controllability.

Further, by providing a means for supplying the solvent after the film formation to eject the gas to the vaporizer and clean the peripheral pipes thereof, and then discarding the solvent, the remaining liquid raw material is swept away by the solvent, and Do not solidify or block at the outlet or peripheral piping.

Further, by adding the solvent vapor to the flow of the diluting gas, it is possible to prevent the vaporization residue and the like adhering to the vicinity of the jet port to the vaporizer from being dissolved by the solvent vapor to prevent precipitation and solidification.

Further, when the vaporizer and the reaction chamber are continuously connected so that their internal spaces communicate with each other, the pipe connecting the vaporizer and the reaction chamber, the heater for heating the vaporizer and the like can be omitted, and the apparatus can be simplified.

Further, the raw material property analyzing means having the light emitting element and the photodetector enables the film formation while confirming the presence or absence of alteration of the liquid raw material or the vaporized raw material gas and the concentration change.

[0029]

EXAMPLES Example 1. Next, an embodiment of the present invention will be described with reference to the drawings. Note that the description of the same parts as those of the conventional technique will be appropriately omitted. FIG. 1 is a first embodiment of the present invention.
FIG. 3 is a schematic view showing an outline of the structure of a CVD apparatus according to the above. In the figure, 1, 2, 6 to 9 are the same as the conventional one, 1
Reference numeral 0 is a raw material container, 11 is a liquid raw material supply device including a metering pump, a mass flow controller, etc., 12 is a nozzle whose tip is obliquely cut to atomize the supplied liquid raw material, and 13 is a raw material container 10. A pressure-feeding gas pipe for feeding the pressure-feeding gas, and 14 is a vaporizer for vaporizing the liquid raw material therein.
Reference numeral 15 is a vaporization space in the vaporizer 14, 16 is a heater for heating the vaporizer 14 to a constant temperature by the output of a temperature detection sensor (not shown), 17 is provided on the outer periphery of the nozzle 12, and the dilution gas feeder 2 is provided. A tapered thin tube as a flow path of the diluent gas that introduces the diluent gas supplied from the vaporizer 14 into the vaporization space 15 in the vaporizer 14. The nozzle 12 is configured such that the tip of the nozzle 12 is positioned. 18 is disposed in a direction substantially vertical to the nozzle 12 and supplies the vaporized source gas to the reaction chamber 6
For transporting the raw material gas, and 19 for the raw material gas transport pipe 18
For keeping heat to a predetermined temperature, 20 is a carburetor 14
It is a filter such as a metal mesh installed at the outlet of the raw material gas communicating from the vaporization space 15 to the raw material gas transport pipe 18.

Next, the operation will be described. Heater 1
After heating the vaporizer 14 to a predetermined temperature of about 200 ° C. by 6, the predetermined amount of dilution gas is supplied from the dilution gas supply device 2 to the vaporization space 15 of the vaporizer 14 through the tapered thin tube 17. The raw material container 10 is supplied with the pressure-fed gas for heating through the pressure-fed gas pipe 13, and the liquid raw material is supplied with the liquid raw material feeder 1.
1 sends to the nozzle 12 at a constant speed. Nozzle 12
Has a tapered thin tube 1 that serves as an inlet to the vaporization space 15.
It is located in the throttle portion 17a of No. 7, and the flow velocity of the dilution gas becomes maximum in that portion. Therefore, the supplied liquid raw material is atomized by the surrounding high-speed dilution gas flow at the tip of the nozzle 12 and jetted out, colliding with a wide range of the inner wall of the heated vaporizer 14 and instantly vaporized. Since the diluent gas flows at high speed on the surface of the liquid raw material during vaporization, the scavenging effect accelerates vaporization and mixing (vaporized gas and diluent gas). The nozzle 1
The tip of 2 is cut obliquely, and the liquid raw material is efficiently atomized at the edge portion of the tip of the nozzle 12. Further, since the nozzle 12 and the raw material gas transport pipe 18 are arranged in the vertical direction, the liquid raw material atomized by the nozzle 12 easily collides with the inner wall of the vaporizer 13.

Next, the vaporized gas and the diluting gas are sent to the raw material gas transport pipe 18 through the filter 20, where the mixing is further promoted and introduced into the reaction chamber 6, and the surface of the substrate 8 is subjected to the CVD reaction. A thin film is formed on. By the way, since the fine particles of the liquid raw material and the solidified particles which have not been sufficiently vaporized in the vaporization space 15 are re-evaporated or trapped by the filter 20, liquid or particulate components are not transported to the reaction chamber 6. Absent. Further, the filter 20 is constructed so as to be easily attached and detached, and when it becomes clogged, it can be promptly replaced and cleaned. Further, the raw material gas transport pipe 18 is kept warm by the warming heater 19 to prevent recondensation of the vaporized gas.

Next, after the film forming operation is completed, the heater 16 is stopped while the diluent gas is flowing to sufficiently cool the carburetor 14, and then the supply of the diluent gas is stopped. This can prevent the liquid raw material slightly remaining in the nozzle 12 from solidifying and deteriorating. Further, when the inside of the pipe such as the nozzle 12 is subjected to a surface treatment such as a fluororesin treatment, the liquid raw material can be smoothly returned to the raw material container 10. Further, in order to make the temperature distribution of the vaporizer 14 uniform, the vessel wall is made of a metal material having a large thermal conductivity such as aluminum, and the inner wall is treated with alumina, glass-coated, or fitted with a quartz tube. It is good to activate.

As described in detail above, in the liquid source CVD apparatus according to the above embodiment, the source container 10 and the vaporizer 14 are separately configured, and the liquid source is heated without heating by an amount necessary for film formation. In this state, it is supplied to the vaporizer 14 and atomized,
The wall surface of the heated vaporizer 14 is instantly vaporized. Therefore, since the liquid raw material in the raw material container 10 is not deteriorated or deteriorated and the concentration is kept constant, particle precipitation and clogging in the raw material container 10 and the piping system are prevented, and the composition is uniform and of good quality. A thin film can be formed. Such an effect is particularly remarkable when the liquid raw material is a solution in which a solid material is dissolved in an organic solvent.
Further, since the tapered thin tube 17 that serves as a flow path for the dilution gas is provided on the outer periphery of the nozzle 12 that supplies the liquid raw material to the vaporizer 14, and the tip of the nozzle 12 is arranged in the narrowed portion 17a, the tip of the nozzle 12 is formed. The liquid raw material supplied from the atomizer 1 is atomized by the surrounding dilution gas flow and ejected to form the vaporizer 1.
Evaporates efficiently within 4 and there is little evaporation residue.

In the above embodiment, the diluting gas is circulated after heating the vaporizer 14. However, the diluting gas is circulated even at the start of heating to suppress the temperature rise of the nozzle 12, so that the inside of the nozzle 12 is prevented. It is possible to further prevent solidification and deterioration of the remaining liquid raw material.

In the above embodiment, the liquid raw material supplied from the nozzle 12 was atomized by the surrounding high-speed dilution gas flow and jetted out, and was vaporized on the wall surface of the vaporizer 14, but the diameter of the nozzle 12 is sufficient. If it is made thin, the liquid raw material becomes finer particles at the tip of the nozzle 12, and is instantly vaporized in the vaporization space 15 before colliding with the wall surface of the vaporizer 14. Further, when the diluent gas flow is supplied at a relatively low speed, the liquid raw material ejected from the tip of the nozzle 12 is in the form of relatively large droplets, but is rapidly vaporized by the scavenging effect of the diluent gas flow.

Example 2. Next, a CVD apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. This is a bypass pipeline 21a in which a pipe connecting the raw material container 10 and the nozzle 12 is provided with an opening / closing valve 22a as an opening / closing valve.
Is provided. The opening / closing valve 22a is driven by an external electric signal, and the opening / closing valve 22a is closed at the time of film formation so that the liquid raw material in the raw material container 10 is fed to the liquid raw material supply device 1
1 and the film formation is completed, the liquid raw material supply device 1
1 is stopped and the opening / closing valve 22a is opened. Thereby, the liquid raw material in the nozzle 12 is bypassed by the bypass line 21a.
Since it returns to the raw material container 10 through the nozzle, it is not heated in the thin tube of the nozzle 12 or at the tip of the nozzle, or solidified to prevent clogging. When a plurality of substrates are continuously processed, the above-mentioned supply operation of the liquid raw material is repeated. Further, by performing a surface treatment such as a fluororesin treatment on the inside of the bypass conduit 21a, the liquid raw material can be smoothly returned to the raw material container.

Example 3. In the second embodiment, the liquid raw material is returned to the raw material container 10 via the bypass conduit 21a, but a case where the returned raw material is returned to another tank will be described with reference to FIG. In the CVD apparatus according to the third embodiment of the present invention shown in FIG. 3, the return pipe 23 and the nozzle 12 that have been decompressed in advance by a decompression device 24 such as a vacuum pump, and the discharge pipe 2 provided with an opening / closing valve 22b as an opening / closing valve.
It is configured by connecting with 1b. When the film formation is completed, the liquid raw material supply device 11 is stopped and the liquid raw material supply device 1
1 and the valves 25 and 26 on the pressure reducing device 24 side are closed, and the valve 22b on the discharge pipe 21b side is opened. As a result, the liquid raw material in the nozzle 12 is absorbed by the depressurized return tank 23. As a result, the same effect as in Example 2 can be obtained, and the next film forming step can be performed without affecting the liquid raw material in the raw material container 10 even if the return raw material is altered in some way.

Example 4. Next, a CVD apparatus according to Embodiment 4 of the present invention will be described with reference to FIG. As shown in the figure, different liquid raw material supply devices 11a and 11 are provided.
Two kinds of liquid raw materials are supplied from the two raw material containers 10a and 10b having b to the vaporizer 14 through the nozzle 12 and vaporized. Therefore, even with two kinds of liquid raw materials having different vapor pressures, the supply amounts can be controlled separately, so that a film with good uniformity can be formed. It should be noted that the number of raw material containers 10 connected to the nozzles 12 is, of course, good even if it is three or more.

Example 5. Next, a CVD apparatus according to Embodiment 5 of the present invention will be described with reference to FIG. In the figure, 27 is a holder for the nozzle 12 (hereinafter referred to as a nozzle holder), and 28 is a heat insulating material that shields heat from the vaporizer 14, which reduces heat conduction from the vaporizer 14 to the nozzle 12 and reduces the nozzle 12 temperature. Prevent heating. Furthermore, the nozzle 12
A solvent tank 29 is connected to a solvent supply device 30 equipped with a valve, and the solvent tank 29 is connected to a pressure-feeding gas pipe 13 and pressurized as in the raw material container 10.

Using such a CVD apparatus, the raw material container 10 contains a solution raw material in which Sr (DPM) ₂ is dissolved in THF, and the solvent tank 29 contains the solvent THF. SrT using N ₂ gas as
The case of forming an iO ₃ film will be described below. At the time of normal film formation, the valve on the solvent tank 29 side is closed, and the solution raw material is passed from the raw material container 10 through the liquid raw material supply device 11,
It is supplied from the nozzle 12 to the vaporizer 14. At this time, the solution raw material is atomized by the N ₂ gas flow around the nozzle 12 and vaporized in the vaporizer 14.

When the film formation is completed, the liquid raw material supply device 11 is stopped, the valve of the solvent supply pipe 30 is opened, and the THF in the solvent tank 29 is supplied to the nozzle 12. Thus, by circulating the solvent after the film formation, the raw material solution which is deteriorated and solidified when left for a long time and may cause clogging of the nozzle 12 is swept away from the nozzle 12, and the inside of the vaporizer 14 is also washed away and vaporized. Residues and deposits can be removed. The supplied solvent is discarded to the outside through the branched raw material gas transport pipe 18 and the like together with the washed-out impurities and the like, so that the reaction chamber is not contaminated. After that, the valve of the pipeline of the solvent supply pipe 30 is closed to stop the CVD apparatus.

Example 6. Next, a CVD apparatus according to Embodiment 6 of the present invention will be described with reference to FIG. As shown in the figure, a bubbler 3 for adding a solvent vapor to a flow path of the diluent gas connected from the diluent gas supplier 2 to the nozzle 12.
1 is set. Further, it is assumed that the tip end opening of the nozzle 12 is treated with a fluororesin.

For example, in order to form a SrTiO ₃ film, a solution raw material in which Sr (DPM) ₂ is dissolved in THF and a N ₂ diluent gas are used. The solution raw material is atomized and ejected at the tip of the nozzle 12, but since the tip end opening portion of the nozzle 12 is treated with a fluororesin, the surface tension with the solution is lowered, and the nozzle opening portion of the solution raw material 12 is reduced. Exudation to the surrounding area is suppressed. Furthermore, since the THF inside the bubbler becomes THF vapor and is added to the N ₂ dilution gas by the bubbler 31, the Sr (D
PM) ₂ is prevented from dissolving in THF vapor and precipitating and solidifying.

Example 7. Next, a CVD apparatus according to Embodiment 7 of the present invention will be described with reference to FIG. As shown in the figure, the vaporizer 14 and the reaction chamber 6 have a continuous structure in which their internal spaces are directly communicated with each other.
To the reaction chamber 6, there is no need for the raw material gas transport pipe 18, there is no need to control the temperature of the raw material gas transport pipe 18, the apparatus can be simplified, and problems such as adhesion of solidified liquid raw material in the pipe are eliminated.

Example 8. Next, a CVD apparatus according to Embodiment 8 of the present invention will be described with reference to FIG. As shown in the figure, a light source 32 such as infrared light (IR) as a light emitting element
Also, a liquid cell 34 as a raw material property analyzing means including a photodetector 33 such as a spectroscope is provided in a pipe portion between the nozzle 12 and the liquid raw material supply device 11.

At the time of film formation, the liquid raw material passing through the liquid cell 34 is subjected to infrared absorption spectroscopy by the IR light source 32 and the photodetector 33, and the presence or absence of alteration of the liquid raw material and the solution based on the shape and absorption amount of the absorption spectrum. A uniform film can be formed while confirming the concentration. It should be noted that the liquid cell 34 is not limited to being installed in the pipe section, and may be installed in a place where a similar configuration can be taken, such as providing a window in the raw material container 10, or
The same effect can be obtained even if a gas cell is installed in the vaporized gas flow path and used as an analysis means.

Further, the raw material property analyzing means is not limited to the method by infrared absorption spectroscopy, and light absorption and fluorescence peculiar to the raw material and foreign matter can be used. Furthermore, when bubbles or solid particles are mixed in the solution or vaporized gas, these bubbles or fixed particles can be detected by measuring the light scattering from the direction perpendicular to the optical axis.

[0048]

As described above, according to the present invention, the CV
In the apparatus D, the raw material container and the vaporizer are separately configured, and a necessary amount of the liquid raw material is supplied to the vaporizer in a liquid state, where it is atomized by a diluent gas and ejected to be vaporized. As a result, the liquid raw material is not altered or deteriorated, and the concentration is kept constant, so particle precipitation and clogging in the raw material container and piping system are prevented, and a uniform and high-quality thin film with no composition deviation is formed. it can.

Further, since the liquid raw material is supplied to the vaporizer by the nozzle, a diluting gas passage is provided on the outer periphery of the nozzle, and the tip of the nozzle is positioned at the narrowed portion of the passage, the liquid raw material is the surrounding diluting gas. Due to the flow, the particles are efficiently atomized and ejected into the vaporizer, and good vaporization with little vaporization residue can be performed.

Further, since the residual liquid raw material is returned by using the bypass pipe, solidification or clogging of the raw material in the jet port to the vaporizer or in the pipe is prevented.

Furthermore, since the liquid raw material is returned to the return tank, the liquid raw material in the raw material container is not affected even if the return raw material is altered.

Further, since the liquid raw material can be supplied from a plurality of raw material containers, a uniform and good quality thin film can be formed even if the liquid raw material is composed of plural kinds of liquids having different vapor pressures.

Further, since the solvent is supplied after the film formation to clean the jet port to the vaporizer and the peripheral pipes, the remaining liquid raw material is flown into the solvent to prevent solidification and clogging.

Further, since the solvent vapor is added to the diluting gas flow, it is possible to prevent the vaporization residue adhering to the vicinity of the jet port to the vaporizer from melting and depositing and solidifying.

Further, since the vaporizer and the reaction chamber are made continuous, the apparatus can be simplified.

Further, since the raw material property analyzing means is provided, it is possible to form a film with good controllability while confirming the presence or absence of alteration of the raw material and the concentration change.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a structure of a CVD apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a structure of a CVD apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing the structure of a CVD apparatus according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing the structure of a CVD apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing the structure of a CVD apparatus according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view showing the structure of a CVD apparatus according to Embodiment 6 of the present invention.

FIG. 7 is a sectional view showing the structure of a CVD apparatus according to Embodiment 7 of the present invention.

FIG. 8 is a sectional view showing the structure of a CVD apparatus according to Example 8 of the present invention.

FIG. 9 is a cross-sectional view showing the structure of a conventional CVD apparatus.

[Explanation of symbols]

 6 Reaction Chamber 8 Processed Substrate 10, 10a, 10b Raw Material Container 11, 11a, 11b Liquid Raw Material Feeder 12 Nozzle 14 Vaporizer 17 Tapered Capillary Tube as Diluting Gas Flow Path 17a Throttle Part 18 Raw Material as Raw Material Gas Flow Path Gas transport pipe 21a Bypass pipe 21b Discharge pipes 22a, 22b Valves as on-off valves 23 Return tank 29 Solvent tank 30 Solvent supply pipe 31 Bubbler supplying solvent vapor 32 IR light source as light emitting element 33 Photodetector 34 Raw material property analysis Liquid cell as a means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Koichiro Tsutahara, 4-chome, Mizuhara, Itami City, Kita Itami Plant, Mitsubishi Electric Co., Ltd. (72) Takashi Higaki, 4-chome, Mizuhara, Itami City Mitsubishi Electric Co., Ltd. ULS I Development Laboratory (72) Inventor Yasuji Matsui 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor Akasa Yuki 8-1-1 Tsukaguchi Honmachi, Amagasaki City 1 Mitsubishi Electric Co., Ltd. Central Research Laboratory (72) Inventor Takaaki Kawahara 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Co., Ltd. Central Research Laboratory (72) Inventor Hideoki Uchikawa 8-1-1 Tsukaguchi Honcho, Amagasaki City No. Mitsubishi Electric Corporation Material Devices Research Laboratory (72) Inventor Hisao Watai 8-1-1 Tsukaguchihonmachi, Amagasaki-shi Mitsubishi Electric In-house company Material Devices Research Laboratory (72) Inventor Shigeru Matsuno 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Material Devices Research Laboratory (72) Inventor Shinichi Kinouchi 8-1-1 Tsukaguchi Honmachi, Amagasaki Mitsubishi Electric Materials Device Laboratory Co., Ltd.

Claims (9)

[Claims] 1. A raw material container for containing the liquid raw material in a CVD apparatus for supplying a vaporized gas obtained by vaporizing a liquid raw material using a diluent gas to a reaction chamber to form a film on a substrate to be processed, and the raw material container. A liquid raw material supply device for taking out the liquid raw material from the liquid raw material, a means for atomizing and ejecting the liquid raw material by receiving the supply of the liquid raw material and the diluent gas from the liquid raw material supply device, and the atomized liquid raw material And a vaporizer for vaporizing the vapor. 2. A liquid raw material sent from a liquid raw material supply device is supplied to a vaporizer by a nozzle, a diluting gas passage is provided on the outer periphery of the nozzle, and the tip of the nozzle is positioned at the narrowed portion of the passage. The CVD according to claim 1, wherein
apparatus. 3. A CV according to claim 1 or 2, wherein a bypass pipe line provided with an on-off valve is provided, which connects a raw material container and a pipe for supplying a liquid raw material supply device to a vaporizer.
D device. 4. A depressurized return tank, wherein the return tank is connected to a pipe for supplying a vaporizer from a liquid raw material supply device by a discharge pipe having an on-off valve. 2. The CDV device described in 2. 5. A plurality of raw material containers for individually storing a plurality of types of liquid raw materials are provided.
The CVD apparatus according to any one of 1. 6. A solvent supply pipe and a solvent tank are used to supply and wash a solvent, after the film is formed, to the jet port for ejecting a solution constituting a liquid raw material to a vaporizer and its peripheral pipe, and then the solvent is discarded. The CVD apparatus according to any one of claims 1 to 5, further comprising: 7. The CVD apparatus according to claim 1, wherein the diluent gas flow path to be supplied to the vaporizer is provided with means for supplying a solvent vapor of a solution forming the liquid raw material. . 8. The CVD apparatus according to claim 1, wherein the vaporizer and the reaction chamber have a continuous structure in which respective internal spaces directly communicate with each other. 9. A raw material property analyzing means having a light emitting element and a photodetector is provided in a raw material container, a pipe from the raw material container to a vaporizer, or a flow path of the vaporized raw material gas. CVD according to any one of claims 1 to 8.
apparatus.