JP2003142468A - Chemical vapor deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical vapor deposition apparatus which can suppress the generation of foreign matters such as residues or the like. SOLUTION: The chemical vapor deposition apparatus is comprised of a CVD raw material vessel, a vaporizer and a reactor 11. The reactor 11 is provided with a reaction chamber 113, a gas head 11a and a wafer stage 11b. The gas head 11a is also provided with a plurality of gas nozzles 11d for blowing a CVD raw material gas and oxygen gas. The gas head 11a is fixed to a wall 12 in the reaction chamber via a ceramic block 45. At the area near the gas nozzles 11d, an aluminum coating layer 46 is formed which is planar- processed at its surface to exceed a predetermined reflection coefficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical vapor deposition apparatus, and more particularly to a chemical vapor deposition apparatus for forming a dielectric thin film such as a semiconductor memory.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor memories and devices has been rapidly advanced. For example, in dynamic random access memory (DRAM), the number of bits is quadruple in three years, which is a rapid pace. This is for the purpose of high integration of the device, low power consumption, low cost, and the like. However, no matter how the degree of integration is improved, the capacitor, which is a constituent element of the DRAM, must have a certain capacitance. For this reason, it is necessary to reduce the film thickness of the material of the capacitor insulating film, and there has been a limit to thinning the SiO ₂ used so far.

Therefore, if the dielectric constant of the capacitor insulating film can be increased by changing the material, the capacitance can be secured as in the case of thinning. For this reason, many companies have been actively researching the use of a thin film made of a high dielectric constant material as a capacitor insulating film of a memory device.

As the performance required for such a capacitor insulating film, it is most important that it is a thin film having a high dielectric constant and a small leak current as described above.
That is, as long as a high dielectric constant material is used, it is necessary to make the film as thin as possible and minimize the leak current. As a development target, it is generally said that a film thickness of 0.5 nm or less in terms of SiO ₂ and a leak current density at the time of applying 1 V of 2 × 10 ⁻⁷ A / cm ² or less are desirable.

Further, in order to form a thin film on a capacitor electrode of a DRAM having a step, the CVD method, which has good coverage on the surface of a complicated shape, is advantageous. In the CVD method, a liquid raw material in which an organic metal complex containing a specific metal is dissolved in an organic solvent is used as a raw material for a thin film having a high dielectric constant. A high dielectric constant thin film is formed by vaporizing the liquid raw material and blowing the gas onto a substrate or the like.

However, it has been a serious problem that there is no liquid raw material that is stable and has good vaporization characteristics. This is because the vaporization property by heating of the compound of β-diketone-based dipivaloylmethane (DPM), which is often used as an organometallic complex, and a metal is not good.

Under these circumstances, the inventors of the present invention have dramatically improved vaporization characteristics by using a liquid raw material prepared by dissolving an organometallic complex in an organic solvent called tetrahydrofuran (THF) in JP-A-6-158328. An improved CVD source has been proposed. However, when this liquid material was applied to a conventional liquid material CVD apparatus to form a dielectric film, it was found that good results were not always obtained.

Therefore, the inventors have proposed a liquid source CVD apparatus capable of sufficiently vaporizing the liquid source and stably supplying it to the reaction chamber (Japanese Patent Laid-Open Nos. 6-310444 and 7-.
094426).

Organometallic complexes containing titanium as a metal
In general, TTIP [Ti (Oi-Pr) 4] is
It is often used. DPM-based TiO (DP
M) ₂By changing to
To form a relatively amorphous film.
At the beginning of film formation, which is easy to form, the initial film is formed by annealing.
After crystallization, the second step of depositing the second layer film is performed.
Good surface morphology and electrical conductivity compared to monolayer film
It has been proposed that it is effective in obtaining the characteristics
7-268634).

Further, a CVD apparatus for a liquid material has been proposed which is equipped with FTIR or the like so that the state of film formation can be optically monitored in-situ. Further, a lower electrode structure and the like suitable for a BST film formed by a solution vaporization CVD method for vaporizing a liquid raw material have been proposed (JP-A-8-176826 and JP-A-8-186103).

However, even if a dielectric film is formed by using this liquid source CVD apparatus (hereinafter referred to as "solution vaporization CVD apparatus"), a good quality film (including electrical characteristics) is not always stable. It turns out that it cannot be formed.

Now, a conventional solution vaporization CVD apparatus will be described. Referring to FIG. 15, the solution vaporization CVD apparatus includes a CVD raw material container 103, a vaporizer 105, and a reaction chamber 11.
1 is provided. In the CVD raw material container 103, liquid C in which an organic metal complex containing a predetermined metal is dissolved in an organic solvent.
VD raw material is stored. The vaporizer 105 vaporizes the liquid CVD raw material sent by the raw material supply device 115. The vaporized CVD raw material is mixed with oxygen as an oxidant in the mixer section 107. Note that oxygen is sent from the oxidant supply pipe 121. The CVD raw material that has been vaporized and mixed with oxygen is supplied from the gas nozzle 111d to the substrate 111.
Sprayed on c. The substrate 111c is the reaction chamber 111e.
It is placed on the stage 111b.

Next, film formation by the solution vaporization CVD apparatus will be described. Pressurizing tube 11 in CVD source container 103
A pressurized gas such as nitrogen is introduced by 3. This allows
The pressure in the CVD source container 103 rises and the liquid CVD source is sent to the vaporizer 105. At this time, the raw material feeder 1
The flow rate of the CVD raw material is controlled by 15. Further, nitrogen is introduced through the carrier gas introduction pipe 104. The liquid CVD raw material is sprayed into the vaporizing chamber in the vaporizer and vaporized to become a CVD raw material gas.

The CVD source gas reaches the mixer section 107 through the source gas transport pipe 117. At this time, the transport pipe heater 1 provided around the source gas transport pipe 117
41 prevents the CVD source gas from liquefying.
Further, the source gas transport pipe 117 has a vent line 152.
Are connected. In the mixer section 107, CVD
The source gas is mixed with oxygen. CVD mixed with oxygen
The raw material gas blows out from the gas nozzle 111d. A thin film is formed on the substrate heated by the substrate heater.

As the liquid raw material, an organic metal complex containing Ba, Sr, and Ti dissolved in an organic solvent is used. Although only one system of the CVD source container 103 is shown in FIG. 15, in reality,
The CVD raw material container 103 is provided in three systems. Liquid CVD raw material is supplied to one vaporizer 105 from each CVD raw material container.

The reaction chamber 111 has an oxygen atmosphere. The pressure is 1 to 10 Torr. Substrate heater set temperature is 40
It is 0-600 degreeC. This is because the lower the temperature during film formation, the better the coverage. Deposition rate is 30
The flow rate of the liquid raw material and the film formation time were controlled so that the film thickness was Å / min and the film thickness was 300Å. The film formed on the substrate is a BST film [(Ba, Sr) TiO ₃ ]. The BST film is formed so that the composition ratio (Ba + Sr) / Ti is 1.0.

Also, BS is formed on the lower electrode of Pt, Ru or the like.
A T film is formed, and Pt and R are further formed on the BST film.
A sample having an upper electrode such as u is formed. Using this sample, the electrical characteristics such as the leak current of the BST film and the equivalent oxide film thickness are measured.

[0018]

[Patent Document 1] Japanese Unexamined Patent Publication No. 6-158328 (Pages 2 to 10, Tables 1 to 11)

[0019]

[Patent Document 2] JP-A-6-310444 (pages 4 to 13, FIGS. 1 to 15)

[0020]

[Patent Document 3] Japanese Patent Laid-Open No. 7-094426 (pages 4 to 6, FIGS. 1 to 8)

[0021]

[Patent Document 4] Japanese Patent Laid-Open No. 7-268634 (No. 11)
(Pages to 25, FIGS. 1 to 26)

[0022]

[Patent Document 5] JP-A-8-176826 (pages 9 to 15, FIGS. 1 to 11)

[0023]

[Patent Document 6] JP-A-8-186103 (pages 7 to 12, FIGS. 1 to 22)

[0024]

Solution vaporization CV described above.
To form the BST film by the D apparatus, a liquid raw material prepared by dissolving a DPM-based organometallic compound in an organic solvent was used as a CVD raw material. In this case, a gas-liquid mixture of a solution raw material and a carrier gas is sprayed from a Teflon (R) nozzle having an outer diameter of 1/6 inch into a vaporization system at a temperature of 250 ° C. At this time,
Clogging occurs at the tip of the nozzle due to condensation of the solution raw material. In addition, a residue is generated on the inner side surface of the vaporization chamber each time film formation is repeated, which causes a problem that a BST film having the same composition and film thickness cannot be stably formed.

In addition, the residue may adhere to the inner wall of the pipe connecting the vaporizer and the reaction chamber. The residue may enter the reaction chamber during film formation and be taken into the film. Therefore, there is a problem that the film quality deteriorates.

Further, the raw material gas is mixed with oxygen as an oxidant in the mixer section. At this time, the temperature rise of oxygen was not sufficient, and the raw material gas was sometimes cooled in the mixer section to cause condensation. Therefore, there is a problem that clogging occurs in the mixer section.

Further, a residue was generated inside the mixer section every time the film formation was repeated. In addition, oxygen having a relatively low temperature was back-diffused in the raw material gas transport pipe, and the raw material gas was cooled during film formation and condensed. Therefore, there arises a problem that it is impossible to stably form a film having the same composition and film thickness.

Further, when introducing the raw material gas into the reaction chamber through the gas nozzle, the temperature of the gas nozzle must be maintained at a temperature higher than the sublimation temperature or the boiling point of the CVD raw material. In particular, Ba (D
C) of DPM-based organometallic compounds represented by PM) ₂ etc.
Since the VD raw material undergoes thermal decomposition when the temperature rises by about 10 to 20 ° C. from the sublimation temperature or the boiling point, the temperature of the gas introduction system needs to be precisely controlled.

However, in particular, the temperature of the end of the gas nozzle of the gas head may rise above a predetermined temperature due to radiant heat from the substrate heated to about 400 to 600 ° C. Alternatively, on the contrary, the temperature may drop below a predetermined temperature due to heat radiation or conduction to a relatively low temperature chamber. Therefore, there is a problem that the vaporized CVD raw material is decomposed or solidified. There is also a problem that the holes of the gas nozzle are clogged.

Further, there is a problem that the reaction product attached to the inner wall of the reaction chamber is peeled off on the substrate during the film formation and the film characteristics are deteriorated.

As described above, the conventional solution vaporization CV is used.
In the D apparatus, foreign matter such as a residue of the CVD raw material adhered to the inside of the vaporizing chamber, the nozzle, the raw material transport pipe, and the like in the apparatus. Further, foreign matter such as reaction products adhered to the inner wall of the reaction chamber.
Therefore, the CVD source gas containing a predetermined flow rate or component may not be sprayed onto the substrate. In addition, foreign matter may fall onto the substrate. As a result, a desired thin film could not be stably formed on the substrate.

The present invention has been made in order to solve the above-mentioned problems, and in a chemical vapor deposition apparatus, CV
It is an object of the present invention to provide a chemical vapor deposition apparatus capable of reducing the generation of foreign substances such as D raw material residues and reaction products.

[0033]

The chemical vapor deposition apparatus according to the first aspect of the present invention is connected to a raw material container for storing a CVD raw material in which a metal compound is dissolved in a solvent, and is connected to the raw material container. A chemical vapor deposition apparatus including a vaporizer for vaporizing the supplied CVD raw material, and a reactor connected to the vaporizer and spraying the vaporized CVD raw material sent from the vaporizer to form a thin film on a substrate. Is. The reactor has a heating means for heating the substrate and a gas nozzle for spraying the vaporized CVD raw material onto the substrate. On the surface of the gas nozzle, a treatment that exceeds the prescribed reflectance for heat rays,
Alternatively, the heat ray is subjected to a treatment that exceeds a predetermined heat absorption property.

According to this structure, first, when the surface of the gas nozzle is subjected to a treatment that exceeds a predetermined reflectance with respect to the heat rays, the gas nozzle has most of the heat rays radiated from the heating means on the surface. Since it reflects (infrared rays), the temperature of the gas nozzle is prevented from rising excessively. Next, when the surface of the gas nozzle is subjected to a treatment that exceeds a predetermined heat absorption property with respect to heat rays, the gas nozzle should positively absorb the heat rays radiated from the heating means and radiate from the gas nozzle. Or compensates for the heat lost by conduction to the reactor or the like and compensates for the temperature of the gas nozzle.

Thus, in any case, the temperature of the gas nozzle is maintained at a substantially constant temperature. This reduces the amount of foreign matter generated by solidification or decomposition of the vaporized CVD raw material. As a result, a predetermined amount of vaporized CVD raw material is stably blown out from the gas nozzle, and the quality of the thin film formed on the substrate is stabilized.

The chemical vapor deposition apparatus according to the second aspect of the present invention comprises a raw material container for storing a CVD raw material in which a metal compound is dissolved in a solvent, and a CVD raw material connected to the raw material container and supplied from the raw material container. The chemical vapor deposition apparatus includes a vaporizer for vaporizing, and a reactor connected to the vaporizer and spraying the vaporized CVD raw material sent from the vaporizer to form a thin film on a substrate. The reactor has a reaction chamber surrounded by a wall surface. The inner wall of the reaction chamber is coated with an inert coating layer, and the inner wall is heated in the temperature range of 300 to 500 ° C.

According to this structure, particularly 300 to 500
Reaction products hardly adhere to the inner wall of the reaction chamber heated to ℃. As a result, the reaction products are prevented from falling onto the substrate, and the quality of the thin film formed on the substrate is stabilized. Further, the inner wall of the reaction chamber can be easily cleaned, and the operating rate of the chemical vapor deposition apparatus is improved.

Preferably, the vaporizer has a nozzle for introducing the CVD raw material into the vaporizer and a nozzle insertion pipe in which the nozzle is inserted. The inert gas is introduced into the nozzle insertion pipe, and the inert gas introduced into the nozzle insertion pipe is blown out from the nozzle side.

According to this structure, particularly when the liquid CVD raw material is sprayed from the nozzle, the sprayed CVD is performed.
Inert gas blows out from the nozzle insertion pipe so as to surround the circumference of the raw material. As a result, the CVD raw material is sprayed smoothly without liquid accumulation, and the nozzle clogging is eliminated. As a result, the liquid CVD raw material is sufficiently vaporized, and a predetermined amount of vaporized CVD raw material is sent to the reactor. As a result, the quality of the thin film formed on the substrate becomes stable.

Preferably, the nozzle is made of stainless steel. In this case, the durability of the nozzle is improved, cleaning is easy, and the nozzle can be repeatedly used.

More preferably, the inner peripheral surface of the nozzle made of stainless steel is coated with Teflon (R). In this case, the wettability between the liquid CVD raw material and the nozzle becomes smaller. Thereby, the spraying of the CVD raw material into the vaporizing chamber is performed more stably. As a result, the quality of the thin film formed on the substrate is further stabilized.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION In the chemical vapor deposition apparatus of the present invention,
By optimizing the vaporizer structure, the vaporization of the CVD raw material is sufficiently performed. The vaporized CVD raw material is stably supplied to the reaction chamber, and the BST film which is a high dielectric constant thin film can be stably formed. Further, a liquid organic solvent as a cleaning liquid is used to clean the raw material transportation pipe between the vaporization chamber and the reaction chamber.
The residue on the inner wall of the raw material transport pipe is removed, and the vaporized CVD raw material can be stably supplied to the reaction chamber.

The surface of the gas nozzle of the gas head is
By coating with a material having a heat absorption rate different from that of the material of the gas head, the temperature of the gas nozzle can be stabilized. Further, by optimizing the method of raising the temperature of oxygen as the oxidant, the vaporized CVD raw material in the mixer section and oxygen can be mixed smoothly.
Further, the reaction chamber inner wall is coated with quartz or a silicon oxide film as an inert coating layer, and the reaction chamber inner wall is heated in a temperature range of 300 to 500 ° C. to deposit a reaction product on the reaction chamber inner wall. Is suppressed and cleaning of the reaction chamber is facilitated. Each of the embodiments will be described below.

Embodiment 1

The chemical vapor deposition apparatus according to the first embodiment will be described with reference to the drawings. Referring to FIG. 1, a chemical vapor deposition apparatus 1 includes a CVD source container 3, a vaporizer 5, and a reactor 11.
It has and. The CVD raw material container 3 is provided with a pressurizing pipe 13 for pressure-feeding the CVD raw material. A raw material supply device 15 for supplying a predetermined amount of CVD raw material is provided between the CVD raw material container 3 and the vaporizer 5.

The CVD raw material that has passed through the raw material feeder 15 is
It is mixed with nitrogen introduced through the carrier gas introduction pipe 4 to form a gas-liquid mixture. A pipe heating heater 33 is provided in the raw material transport pipe 17 that connects the vaporizer 5 and the mixer unit 7. Further, the raw material transport pipe 17 has a vent line 52 for discharging unnecessary CVD raw material at the time of purging or the like.
Is provided.

The reactor 11 is provided with a mixer section 7. An oxidant supply pipe 21 is connected to the mixer section 7 to supply oxygen as an oxidant. The oxidant supply pipe 21 is provided with an oxidant heater 9.
The reactor 11 has a reaction chamber 11e. In the reaction chamber 11e, a gas head 11a for blowing out the vaporized CVD raw material and a stage 11b for mounting the substrate 11c are provided.

As the liquid raw material, an organic metal complex containing Ba, Sr and Ti dissolved in an organic solvent is used. More specifically, as the organometallic complex, barium dipivaloyl methanate [Ba (DPM) ₂ ], strontium dipivaloyl methanate [Sr (DPM)
₂ ] and titanyl dipivaloyl methanate [TiO 2
(DPM) ₂ ] is used. Tetrahydrofuran [THF] is used as the solvent. In this case, BST on the substrate
A film (BaSr) TiO ₃ is formed.

In FIG. 1, the CVD source container 3
Although only one system is shown, the CVD raw material container 3 is actually provided with three systems. The liquid raw material is supplied to one vaporizer 5 from each CVD raw material container.

Particularly, in the case of the present chemical vapor deposition apparatus, the vaporizer 5 has a structure shown in FIGS. 2 (a) to 2 (c). 2 (a) is a top view of the vaporizer, FIG. 2 (b) is a sectional view taken along the line AA shown in FIG. 2 (a), and FIG. 2 (c) is a sectional view taken along the line BB shown in FIG. 2 (a). Are shown respectively. Referring to FIG. 2B, the vaporizer 5 has a vaporization chamber 5f formed by the vaporizer upper portion 5d and the vaporizer lower portion 5e. Vaporization chamber 5
f has a substantially cylindrical shape. A nozzle insertion pipe 5b is provided on the vaporizer upper portion 5d, and a nozzle 5c is attached to the vaporizer upper portion 5d. That is, the nozzle 5c is attached to the peripheral surface 6 corresponding to the cylindrical side surface of the columnar vaporization chamber 5f. The nozzle is made of Teflon (R) and has an outer diameter of 1/16 inch. The outer diameter of the nozzle insertion pipe 5b is 1/8 inch.

Further, the vaporizer lower portion 5e is provided with a raw material transport pipe connecting hole 5g for feeding the raw material gas to the reaction chamber. That is, the raw material transportation pipe is connected to the peripheral surface 6. A rod heater 5h is provided on the vaporizer upper portion 5d and the vaporizer lower portion 5e. This rod heater 5h
Thus, the inside of the vaporization chamber 5f is maintained at about 250 ° C.

Next, the thin film formation by this chemical vapor deposition apparatus will be described. With reference to FIG. 1 and FIG. 2B, the liquid CVD raw material in the CVD raw material container is the pressure pipe 13
It is pressure-fed by a pressurized gas such as nitrogen introduced into and is sent to the vaporizer 5. At this time, the raw material supplier 15 controls the flow rate of the liquid CVD raw material. In addition, the raw material feeder 1
After passing through 5, the liquid CVD raw material and nitrogen as a carrier gas are mixed to form a gas-liquid mixture. The gas-liquid mixture is sprayed from the nozzle 5c and circulates in the vaporization chamber 5f along the peripheral surface 6 in the vaporization chamber 5f.

Due to this flow, the gas-liquid mixture becomes the vaporization chamber 5f.
The time to stay inside is longer. Therefore, the liquid CV
The D raw material is sufficiently vaporized, and the residue in the vaporization chamber 5f is reduced. The vaporized CVD raw material becomes a CVD raw material gas. The CVD raw material gas reaches the mixer section 7 via the raw material transport pipe 17. In the mixer section 7, the CVD source gas is mixed with oxygen as an oxidant. C mixed with oxygen
The VD raw material gas is sprayed onto the substrate 11c through a plurality of gas nozzles 11d provided in the gas head 11a.

According to this structure, in particular, the time during which the gas-liquid mixture stays in the vaporization chamber 5f becomes longer. As a result, the liquid CVD raw material is sufficiently vaporized, and the amount of residue in the vaporization chamber 5f is reduced. The vaporized CVD raw material is stored in the vaporization chamber 5
It is discharged from the raw material transport pipe connection hole 5g provided in the peripheral surface 6 without disturbing the flow circulating in the inside f. A certain amount of CV
D source gas is sent to the reactor 11. As a result, a BST film having the same film quality can be stably formed over a long period of time. Specifically, the cleaning inside the vaporizer 5 could be reduced from once every 100 conventional BST films were deposited to once every 300 BST films were deposited.

Embodiment 2

The chemical vapor deposition apparatus according to the second embodiment will be described with reference to the drawings. In this chemical vapor deposition apparatus, the vaporizer has a structure shown in FIG. That is, FIG.
Nozzle insertion pipe 5 in which the nozzle 5c is inserted
b is provided so that the direction in which the gas-liquid mixture blown out from the nozzle 5c is blown out is particularly along the tangential direction of the peripheral surface 6 of the vaporization chamber 5f. Since the other configurations are the same as those of the chemical vapor deposition apparatus described in the first embodiment, detailed description will be omitted.

According to this chemical vapor deposition apparatus, the gas-liquid mixture introduced into the vaporization chamber is the smoothest in the vaporization chamber 5f along the peripheral surface 6 of the vaporization chamber 5f without turbulence. Circulate to. As a result, the time during which the gas-liquid mixture stays in the vaporization chamber 5f becomes longer. Therefore, the liquid CVD raw material is vaporized more sufficiently, and the amount of residue in the vaporization chamber 5f is reduced. As a result, the film formation can be stably performed for a long time. Specifically, cleaning of the inside of the carburetor has been performed by the conventional method B.
It was possible to reduce the frequency from once every 100 ST films were formed to once every 400 400 films.

Further, as shown in FIG. 3, vaporized CV
D Raw material transport pipe connection 5 for guiding the raw material gas to the reactor
g may be provided on the peripheral surface 6 below the vaporization chamber 5f. In this case, the reactor is arranged immediately below the vaporizer 5, and the vaporizer and the reactor are connected by a substantially linear raw material transport pipe. This makes it possible to construct a chemical vapor deposition apparatus having a simpler structure.

Embodiment 3

The chemical vapor deposition apparatus according to the third embodiment will be described with reference to the drawings. In the present chemical vapor deposition apparatus, the vaporizer has a structure shown in FIG. That is, referring to FIG. 4, the carburetor 5 includes a nozzle insertion pipe 5i with an assist gas introduction port provided with an introduction port for introducing the assist gas 5j into the pipe into which the nozzle 5c is inserted. The outer diameter of the nozzle insertion pipe 5i with the assist gas inlet is 1
/ 8 inch. The outer diameter of the nozzle 5c is 1/16 inch. The other configurations are similar to those of the chemical vapor deposition apparatus described in the second embodiment, and detailed description thereof will be omitted.

According to this chemical vapor deposition apparatus, when the gas-liquid mixture is sprayed from the nozzle, the assist gas is simultaneously sprayed so as to surround the periphery of the gas-liquid mixture. As a result, the gas-liquid mixture sprayed from the nozzle is smoothly sprayed without pooling. Therefore, clogging of the CVD raw material at the tip of the nozzle is prevented. The assist gas also has an effect of preventing the nozzle and the gas-liquid mixture from rising above a predetermined temperature.

An inert gas such as nitrogen is preferable as the assist gas. Stainless steel may be used as the material of the nozzle. In this case, the vaporization chamber 5f
The shape of is not limited to a cylindrical shape, and may be, for example, a prismatic shape.

Embodiment 4

The chemical vapor deposition apparatus according to the fourth embodiment will be described with reference to the drawings. In this chemical vapor deposition apparatus, the vaporizer has a structure shown in FIG. That is, referring to FIG. 5, a concave portion 5k is formed on the peripheral surface 6 of the vaporization chamber 5f. A tape heater 5m is provided on the vaporizer upper portion 5d and the vaporizer lower portion 5e. The other configurations are similar to those of the chemical vapor deposition apparatus described in the first embodiment, and therefore detailed description thereof will be omitted.

According to this chemical vapor deposition apparatus, the surface area of the peripheral surface 6 is increased by the recess 5k. The gas-liquid mixture introduced into the vaporization chamber 5f circulates along the peripheral surface 6 in the vaporization chamber 5f. At that time, the liquid CVD raw material attached to the peripheral surface 6 is vaporized more quickly. As a result, the liquid CVD raw material is vaporized more sufficiently. In the conventional vaporizer, the residue that was left without being vaporized was generated in the vaporization chamber, but in the vaporizer of this structure, almost no residue was generated. Also, liquid C
By sufficiently vaporizing the VD raw material, the uniformity of the film quality such as the composition ratio of the BST film was further improved.

Although the concave portion 5k is formed on the peripheral surface 6 of the vaporization chamber 5f, the same effect can be obtained by forming the convex portion.

Embodiment 5

A chemical vapor deposition apparatus according to Embodiment 5 will be described with reference to the drawings. In the present chemical vapor deposition apparatus, in particular, the vaporizer has the structure shown in FIG. That is, referring to FIG. 6, in vaporizer 5, vaporizer chamber 5f is formed by vaporizer upper portion 5d and vaporizer lower portion 5e. A nozzle 5c is attached to the vaporizer upper portion 5d. The nozzle 5c is
It is made of stainless steel and has a nozzle tip portion 26a and a nozzle thick portion 26b. The outer diameter of the nozzle tip portion 26a is 1/16 inch. The outer diameter of the thick wall portion 26b of the nozzle is 30 mm. Vaporizer upper part 5d and nozzle thick part 26
An aluminum constant temperature plate 24 and a heat resistant O-ring 2 are provided between b and
5 are provided. Since the other configurations are the same as those of the chemical vapor deposition apparatus described in the first embodiment, detailed description will be omitted.

By the way, the vaporization chamber 5f has a rod heater 5h.
Is maintained at about 250 ° C. In the case of the present chemical vapor deposition apparatus, since the nozzle 5c is made of stainless steel, it is not deformed by heat as compared with the nozzle made of Teflon (R). Further, the nozzle 5c has a nozzle tip portion 26a and a nozzle thick portion 26b. Therefore, the heat of the nozzle tip portion 26a is easily conducted to the nozzle thick portion 26b. As a result, the temperature of the nozzle rises only near the tip of the nozzle, and clogging of the CVD raw material is suppressed at the nozzle. A predetermined amount of CVD raw material is sprayed from the nozzle. As a result, the BST film can be stably formed over a long period of time. Specifically, the cleaning inside the vaporizer could be reduced from once every 100 BST films were deposited to once every 300 BST films were deposited.

The sectional shape of the vaporization chamber 5f is substantially rectangular in FIG. 6, but it goes without saying that the same effects can be obtained even with the structures described in the first to fourth embodiments.

Embodiment 6

A chemical vapor deposition apparatus according to Embodiment 6 will be described with reference to the drawings. In this chemical vapor deposition apparatus, the nozzle for introducing the CVD raw material into the vaporization chamber has the structure shown in FIG. That is, referring to FIG. 7, the nozzle 5c
In this, a Teflon (R) impregnated layer 28 is formed with a porous ceramics 27 interposed on a stainless steel portion 29 of the nozzle. FIG. 7B shows a cross section taken along the line AA shown in FIG. For other configurations, the chemical vapor deposition apparatus described in the first to fifth embodiments, or
The configuration is the same as the combination thereof. Therefore, detailed description is omitted.

According to this chemical vapor deposition apparatus, the Teflon (R) impregnated layer 28 is formed on the inner surface of the nozzle. Since Teflon (R) is a material having extremely low wettability, the gas-liquid mixture can be smoothly supplied to the vaporization chamber without being stagnant. As a result, it has become possible to significantly reduce the clogging of the nozzle. Specifically, the cleaning of the inside of the vaporizer is performed once every 100 BST films are formed.
It was possible to reduce the frequency to once every 400 film formation. Further, the film quality characteristics such as the composition ratio of the BST film were improved.

Embodiment 7

A chemical vapor deposition apparatus according to Embodiment 7 will be described with reference to the drawings. In the present chemical vapor deposition apparatus, in particular, the raw material transport pipe 17 for sending the CVD raw material vaporized by the vaporizer 5 to the reactor 11 has a structure shown in FIG. That is, referring to FIG. 8, a liquid organic solvent supply valve 31 for introducing the liquid organic solvent 30 as a cleaning liquid is provided in the vicinity of the raw material transportation pipe 17 and the vaporizer 5. Also,
A liquid organic solvent discharge valve 34 for discharging the liquid organic solvent introduced into the raw material transport pipe 17 is provided near the raw material transport pipe 17 and the reactor 11. The configuration other than this is the same as the chemical vapor deposition apparatus described in the first to sixth embodiments or the configuration in which they are combined. Therefore, detailed description is omitted.

According to this chemical vapor deposition apparatus, after the BST film is finished, the liquid organic solvent supply valve 31 is opened and the liquid organic solvent 30 is supplied to the raw material transportation pipe 17 while the temperature of the raw material transportation pipe 17 is lowered to room temperature. Pour into 17. Raw material transport piping 1
The organic solvent poured into 7 cleans the inner wall of the raw material transportation pipe and is discharged from the liquid organic solvent discharge valve. As a result, foreign substances such as residues attached to the inner wall of the raw material transport pipe 17 are removed, and the CVD raw material gas can be stably supplied from the vaporization chamber to the reactor. As a result, the quality of the thin film formed on the substrate becomes stable.

As the liquid organic solvent, it is preferable to apply the same tetrahydrofuran as the solvent. A vent line may be used for discharging the cleaning liquid.

Embodiment 8

A chemical vapor deposition apparatus according to Embodiment 8 will be described with reference to the drawings. In this chemical vapor deposition apparatus, the vaporizer and the raw material transport pipe have the structure shown in FIG. That is, referring to FIG. 9, nozzle 5c and raw material transportation pipe connection hole 5g are provided so as to be substantially in the vertical direction via vaporization chamber 5f. In this case, the organic solvent as the cleaning liquid is introduced into the nozzle 5c. Nozzle 5c
The organic solvent that has come out of the above reaches the raw material transport pipe connection hole 5 g and is introduced into the raw material transport pipe 17. The organic solvent introduced into the raw material transport pipe 17 is discharged from the liquid organic solvent discharge valve 34. As a result, foreign matter attached to the inner wall of the nozzle and the raw material transport pipe is removed, and the CVD raw material gas can be stably supplied to the reactor. As a result, the quality of the thin film formed on the substrate is further stabilized.

As the vaporizing chamber, any one of Embodiments 1 to 4 can be used.
Needless to say, the columnar vaporization chamber described in 1) has the same effect.

Ninth Embodiment

A chemical vapor deposition apparatus according to Embodiment 9 will be described with reference to the drawings. In this chemical vapor deposition apparatus, the oxidizer heater has the structure shown in FIGS. 10 (a) and 10 (b).
Note that FIG. 10B is a vertical cross-sectional structure diagram of the oxidizer heater shown in FIG. With reference to FIG. 10B, the oxidant heater 9 has an oxidant supply port 35, a spiral groove 37, an oxidant discharge port 38, and a halogen lamp 36.
The other configurations are the same as those of the chemical vapor deposition apparatus described in the first to eighth embodiments or a combination thereof. Therefore, detailed description is omitted.

Oxygen as the oxidant supplied from the oxidant supply port 35 flows along the spiral groove 37. At this time,
The oxygen is heated by the halogen lamp 36. Since the oxygen flows along the spiral groove 37, the oxygen is sufficiently heated by the halogen lamp 36. The sufficiently heated oxygen is sent from the oxidant discharge port 38 to the mixer section. Oxygen was sufficiently heated by this oxidizer heater 9, and the amount of residue of the CVD raw material produced by mixing with oxygen in the mixer section became zero.

Also, back diffusion of oxygen into the raw material transport pipe was almost eliminated. As a result, the temperature of the CVD source gas is not lowered, and stable long-term film formation on the substrate is possible.
Specifically, cleaning of the mixer part is performed by BST film formation 1
It was possible to reduce the frequency from once for every 00 film formation to once for every 800 or more BST films.
Further, the variation in the composition ratio of the BST film was also extremely small.

Embodiment 10

A chemical vapor deposition apparatus according to the tenth embodiment will be described with reference to the drawings. In this chemical vapor deposition apparatus, the reactor has the structure shown in FIG. That is, FIG.
Referring to, the reactor 11 has a reaction chamber 11e, a gas head 11a, and a wafer stage 11b for mounting the substrate 11c. CVD is used for the gas head 11a.
A plurality of gas nozzles 11d for blowing out the raw material gas and the oxygen gas are provided. The wafer stage 11b has
A substrate heater 43 for heating the substrate 11c is provided. The gas head 11 a is fixed to the reaction chamber inner wall 12 via the ceramic block 45. In the vicinity of the gas nozzle 11d, an aluminum coating layer 4 which has been subjected to a treatment exceeding a predetermined reflectance and whose surface has been smoothed
6 is formed. The rest of the configuration is the same as that of the chemical vapor deposition apparatus described in the first to ninth embodiments or a combination thereof. Therefore, detailed description is omitted.

The CVD source gas and oxygen 40 are introduced into the gas head 11a without lowering the temperature thereof by the source introduction pipe heater 41. Heater 4 for raw material introduction piping
The temperature of 1 is about 250 ° C. CV at this temperature
The D source gas does not decompose or solidify. The CVD source gas and oxygen introduced into the gas head 11a are sprayed onto the substrate 11c through the plurality of gas nozzles 11d. The substrate 11c is 400 to 600 by the substrate heater 43.
It is heated in the temperature range of ° C. BS on the substrate 11c
A T film is formed.

The gas head 11a is fixed to the reaction chamber inner wall 12 by the ceramic block 45.
Since the ceramic block 45 has a low thermal conductivity, it suppresses the heat in the vicinity of the gas nozzle 11d from being conducted to the inner wall 12 of the reaction chamber. Thereby, the gas head 11a
It is possible to prevent the temperature from decreasing. Also, the gas nozzle 1
Since the surface of the aluminum coating layer 46 formed near 1d is smoothed, the substrate heater 43
Most of the heat rays radiated from the are reflected at the surface. As a result, the temperature in the vicinity of the gas nozzle 11d is prevented from rising excessively, and is maintained at approximately 250 ° C. As a result, the CVD source gas is not decomposed in the vicinity of the gas nozzle 11d, and a predetermined amount of the CVD source gas is transferred to the substrate 11c.
Sprayed on. As a result, the BST film can be stably formed.

The smoothing treatment applied to the aluminum coating layer 46 is such that the reflectance with respect to the heat rays (the ratio of the energy of the heat rays reflected on the surface to the energy of the heat rays incident on the surface) becomes higher. Any treatment may be applied, and for example, mirror finishing may be performed. Further, the material is not limited to aluminum as long as it is a material having a higher reflectance with respect to heat rays by the smoothing treatment.

Further, the treatment is not limited to the above-mentioned means as long as the treatment is performed so as to have a reflectance that reflects the heat rays and does not excessively raise the temperature of the gas nozzle.

Embodiment 11

The chemical vapor deposition apparatus according to Embodiment 11 will be described with reference to the drawings. In this chemical vapor deposition apparatus, the reactor 11 has the structure shown in FIG. That is, referring to FIG. 12, a treatment exceeding a predetermined heat absorption property is applied to the vicinity of the gas head 11a, and the alumite black layer 47 is formed.
Are formed. Here, heat absorption means the ease of absorbing heat. The gas head 11a is directly fixed to the inner wall 12 of the reaction chamber. Structures other than this are the same as those of the chemical vapor deposition apparatus described in the tenth embodiment, and detailed description thereof will be omitted.

In the reactor 11, the gas nozzle 11d
From the gas nozzle 11d or conduction from the vicinity of the gas nozzle 11d to the inner wall 12 of the reaction chamber, the temperature near the gas nozzle 11d decreases. However,
An alumite black layer 47 is formed near the gas nozzle 11d. The alumite black layer 47 positively absorbs the heat rays radiated from the substrate heater 43 and compensates the temperature of the gas nozzle 11d, so that the temperature of the gas nozzle 11d is maintained at about 250 ° C. As a result, a predetermined amount of the CVD source gas is sprayed onto the substrate 11c without the CVD source gas solidifying near the gas nozzle 11d. As a result, the BST film can be stably formed.

In addition to the black alumite layer, for example, alumina or SiC (silicon carbide) may be used.

Further, the treatment exceeding the predetermined heat absorption property is not limited to the above-mentioned means as long as it is a treatment for absorbing the heat ray capable of compensating the temperature of the gas nozzle.

Twelfth Embodiment

A chemical vapor deposition apparatus according to the twelfth embodiment will be described with reference to the drawings. In this chemical vapor deposition apparatus, the reaction chamber has the structure shown in FIG. That is, FIG.
Referring to, a silicon oxide film 49 as an inactive coating layer is formed on the surfaces of the reaction chamber inner wall 12 and the stage 11b. A gas head heater 48 is formed on the gas head 11a. A heater 50 for the reaction chamber inner wall is provided outside the reaction chamber inner wall 12. The configuration other than this is the same as the chemical vapor deposition apparatus described in the first to eleventh embodiments, or a configuration in which they are combined. Therefore, detailed description is omitted.

The CVD source gas and oxygen 40 introduced into the gas head 11a are sprayed onto the substrate 11c from the gas nozzle 11d and diffused in the reaction chamber 11. Reaction chamber wall 1
2 is heated to a predetermined temperature by the heater 50 for the reaction chamber inner wall. At this time, at 200 ° C. or lower, the CVD source gas may be liquefied and adhered, and at 500 ° C. or higher, the reaction product may adhere.
It is desirable to be heated to 0 ° C, 300 to 500
C is even more desirable. In this temperature range, reaction products hardly adhere to the reaction chamber inner wall 12 covered with the silicon oxide film 49. As a result, almost no foreign matter drops from the inner wall of the reaction chamber onto the substrate 11c. Further, the inside of the reaction chamber 11e is very easily cleaned, and the operating rate of the chemical vapor deposition apparatus can be increased.

Embodiment 13

A chemical vapor deposition apparatus according to the thirteenth embodiment will be described with reference to the drawings. This chemical vapor deposition apparatus has a reaction chamber 1
1 has the structure shown in FIG. That is, with reference to FIG. 14, particularly, the reaction chamber inner wall 12 and the stage 11b
A quartz layer 51 as an inert coating layer is formed on the surface of the. Structures other than this are the same as those of the chemical vapor deposition apparatus described in the twelfth embodiment, and detailed description thereof will be omitted.

As described in the twelfth embodiment,
The reaction chamber inner wall 12 is heated to 30 by the reaction chamber inner wall heater 50.
It is heated in the temperature range of 0 to 500 ° C. As a result, reaction products hardly adhere to the reaction chamber inner wall 12 covered with the quartz layer 51. As a result, almost no foreign matter drops from the inner wall of the reaction chamber onto the substrate 11c. Further, the reaction chamber 11 can be easily cleaned, and the operating rate of the apparatus can be increased.

In each of the above embodiments, B is formed on the substrate.
An organometallic complex as a metal compound was used to form the ST film (BaSr) TiO ₃ . More specifically,
Barium dipivaloyl methanate [Ba (DP
M) ₂ ], strontium dipivaloyl methanate [S
r (DPM) ₂ ] and titanyl dipivaloyl methanate [TiO (DPM) ₂ ] were used. Further, an organic solvent was used as a solvent, and more specifically, tetrahydrofuran [THF] was used.

In addition to this, as a CVD raw material, B on the substrate is used.
Any raw material that can form the ST film (BaSr) TiO ₃ may be used, and other organometallic complexes containing Ba, Sr, and Ti, or metal compounds containing these metals may be used. Further, the solvent is not limited to the organic solvent, and another solvent may be used.

It should be considered that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is shown not by the scope described above but by the claims, and is intended to include all modifications within the meaning and range equivalent to the claims.

[0105]

According to the chemical vapor deposition apparatus of the first aspect of the present invention, first, in the case where the surface of the gas nozzle is subjected to a treatment for the heat ray exceeding a predetermined reflectance,
Since the gas nozzle reflects most of the heat rays (infrared rays) radiated from the heating means on its surface, it is possible to prevent the temperature of the gas nozzle from rising excessively. Next, when the surface of the gas nozzle is subjected to a treatment that exceeds a predetermined heat absorption property for heat rays, the gas nozzle should positively absorb the heat rays radiated from the heating means and radiate the heat rays from the gas nozzle. Or compensates for the heat lost by conduction to the reactor or the like and compensates for the temperature of the gas nozzle.

In this way, in any case, the temperature of the gas nozzle is maintained at a substantially constant temperature. This reduces the amount of foreign matter generated by solidification or decomposition of the vaporized CVD raw material. As a result, a predetermined amount of vaporized CVD raw material is stably blown out from the gas nozzle, and the quality of the thin film formed on the substrate is stabilized.

According to the chemical vapor deposition apparatus of the second aspect of the present invention, the reaction product hardly adheres to the inner wall of the reaction chamber heated to 300 to 500 ° C. As a result, the reaction products are prevented from falling onto the substrate, and the quality of the thin film formed on the substrate is stabilized. Further, the inner wall of the reaction chamber can be easily cleaned, and the operating rate of the chemical vapor deposition apparatus is improved.

Preferably, the vaporizer has a nozzle for introducing the CVD raw material into the vaporizer and a nozzle insertion pipe in which the nozzle is inserted. The inert gas is introduced into the nozzle insertion pipe, and the inert gas introduced into the nozzle insertion pipe is blown out from the nozzle side.

According to this structure, particularly, when the liquid CVD raw material is sprayed from the nozzle, the sprayed CVD is performed.
Inert gas blows out from the nozzle insertion pipe so as to surround the circumference of the raw material. As a result, the CVD raw material is sprayed smoothly without liquid accumulation, and the nozzle clogging is eliminated. As a result, the liquid CVD raw material is sufficiently vaporized, and a predetermined amount of vaporized CVD raw material is sent to the reactor. As a result, the quality of the thin film formed on the substrate becomes stable.

Further preferably, the nozzle is made of stainless steel. In this case, the durability of the nozzle is improved, cleaning is easy, and the nozzle can be repeatedly used.

More preferably, the inner peripheral surface of the nozzle made of stainless steel is coated with Teflon (R). In this case, the wettability between the liquid CVD raw material and the nozzle becomes smaller. Thereby, the spraying of the CVD raw material into the vaporizing chamber is performed more stably. As a result, the quality of the thin film formed on the substrate is further stabilized.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a chemical vapor deposition apparatus according to a first embodiment of the present invention.

FIG. 2A is a top view of a vaporizer of the chemical vapor deposition apparatus according to the first embodiment, and FIG. 2B is a view shown in FIG.
FIG. 6B is a cross-sectional view taken along line A in FIG.
It is sectional drawing in B.

FIG. 3 is a sectional view showing a structure of a vaporizer of a chemical vapor deposition apparatus according to a second embodiment.

FIG. 4 is a sectional view showing a structure of a vaporizer of a chemical vapor deposition apparatus according to a third embodiment.

FIG. 5 is a sectional view showing a structure of a vaporizer of a chemical vapor deposition apparatus according to a fourth embodiment.

FIG. 6 is a sectional view showing a structure of a vaporizer of a chemical vapor deposition apparatus according to a fifth embodiment.

FIG. 7 (a) shows a vertical cross-sectional structure of a nozzle of a vaporizer of a chemical vapor deposition apparatus according to Embodiment 6, and (b) shows
It is a figure which shows the cross section in AA shown to (a).

FIG. 8 is a sectional view showing a structure of a vaporizer of a chemical vapor deposition apparatus according to a seventh embodiment.

FIG. 9 is a sectional view showing a structure of a vaporizer of a chemical vapor deposition apparatus according to an eighth embodiment.

FIG. 10 is a sectional view showing the structure of an oxidizer heater of a chemical vapor deposition apparatus according to Embodiment 9.

FIG. 11 is a sectional view showing a structure of a reaction chamber of a chemical vapor deposition apparatus according to a tenth embodiment.

FIG. 12 is a sectional view showing a structure of a reaction chamber of a chemical vapor deposition apparatus according to an eleventh embodiment.

FIG. 13 is a sectional view showing a structure of a reaction chamber of a chemical vapor deposition apparatus according to a twelfth embodiment.

FIG. 14 is a sectional view showing a structure of a reaction chamber of a chemical vapor deposition apparatus according to a thirteenth embodiment.

FIG. 15 is a diagram showing a configuration of a conventional chemical vapor deposition apparatus.

[Explanation of symbols]

1 Chemical Vapor Deposition Equipment, 3 CVD Raw Material Container, 5 Vaporizer, 7 Mixer Section, 9 Oxidizer Heater, 11 Reactor, 11a Gas Head, 11b Stage, 11c
Substrate, 11d gas nozzle.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayoshi Tarutani             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Tsuyoshi Horikawa             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 4K030 EA01 EA04 JA10 KA09 KA24                       KA46 KA47 LA19                 5F045 AA04 AB31 AC07 BB03 CA05                       DP03 EC05 EE02 EF05 EF11

Claims (5)

[Claims] 1. A raw material container for storing a CVD raw material in which a metal compound is dissolved in a solvent, a vaporizer connected to the raw material container and vaporizing the CVD raw material supplied from the raw material container, and connected to the vaporizer. And a reactor for spraying the vaporized CVD raw material sent from the vaporizer to form a thin film on a substrate, wherein the reactor is for heating the substrate. It has a heating means and a gas nozzle for spraying the vaporized CVD raw material onto the substrate, and the surface of the gas nozzle is subjected to a treatment that exceeds a predetermined reflectance for heat rays, or a predetermined heat for the heat rays. A chemical vapor deposition apparatus that has undergone a treatment that exceeds its absorbability. 2. A raw material container for storing a CVD raw material in which a metal compound is dissolved in a solvent, a vaporizer connected to the raw material container for vaporizing the CVD raw material supplied from the raw material container, and connected to the vaporizer. And a reactor for forming a thin film on a substrate by spraying the vaporized CVD raw material sent from the vaporizer, wherein the reactor is a reaction surrounded by a wall surface. A chemical vapor deposition apparatus having a chamber, which coats an inner wall surface of the reaction chamber with an inert coating layer and heats the inner wall surface in a temperature range of 300 to 500 ° C. 3. The vaporizer has a nozzle for introducing a CVD raw material into the vaporizer, and a nozzle insertion pipe in which the nozzle is inserted, and an inert gas is introduced into the nozzle insertion pipe,
The chemical vapor deposition apparatus according to claim 1, wherein the inert gas introduced into the nozzle insertion pipe is blown out from the nozzle side. 4. The chemical vapor deposition apparatus according to claim 3, wherein the nozzle is made of stainless steel. 5. A Teflon (R) is formed on the inner peripheral surface of the nozzle.
The chemical vapor deposition apparatus according to claim 4, which is coated with.