JP2004289035A - Chemical vapor deposition method and chemical vapor deposition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a thin film particles of which can be measured by on-the-spot observation. <P>SOLUTION: A chemical vapor deposition method includes steps of (a) vaporizing a film-formation raw material solution to form a raw gas; (b) transporting a substrate into a room provided with a particle counter, and introducing the gas onto the substrate while keeping a film formation gas containing the raw material gas at a temperature not lower than a vaporization temperature and lower than a decomposition temperature; (c) measuring the number of particles on the substrate after the step (b); and (d) increasing the substrate temperature to a temperature not lower than the decomposition temperature to form a thin film when the number of particles is not larger than a predetermined number after the step (c). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a chemical vapor deposition method and a chemical vapor deposition apparatus, and more particularly, to a chemical vapor deposition method and a chemical vapor deposition apparatus suitable for growing an insulating thin film that is easily crystallized.
[0002]
[Prior art]
In a chemical vapor deposition (CVD) apparatus, a shower head and a susceptor with a heater are usually arranged opposite to each other in a reaction chamber that can be evacuated, and raw material gas flows down from the shower head onto a substrate on the susceptor, and is heated on the heated substrate. The source gas is thermally decomposed to form a desired film. When film formation is performed using plasma instead of or together with heat, it is called plasma CVD. When an organic metal is used as a raw material, it is also called an organic metal (MO) CVD.
[0003]
A nonvolatile memory using a ferroelectric thin film such as Pb (ZrTi) O ₃ (PZT) as a capacitor dielectric film has been developed. The ferroelectric film is formed by a sol-gel method, sputtering, or the like. As the degree of integration of memories increases, it is desired that ferroelectric capacitors be miniaturized. It is becoming difficult to promote thinning by the sol-gel method or sputtering or to improve step coverage.
[0004]
A method of forming a ferroelectric film by CVD is also known. If the film is formed by CVD, the film thickness can be easily controlled and the film can be made thinner. Good step coverage. For example, a method of forming a ferroelectric thin film by MOCVD has been proposed (for example, Patent Documents 1 and 2).
[0005]
Ferroelectrics generally have the property of being easily crystallized. In order to utilize the properties as a ferroelectric, it is also required to generate a certain orientation. For example, when a ferroelectric film is grown with (100) plane preferentially oriented to (111), the film surface tends to have many tops exposed on the film surface, and the film surface is rough.
[0006]
In CVD of a ferroelectric film, particles are easily generated. When the particles adhere, they cause abnormal growth in CVD and cause a disturbance in the film thickness distribution. In some cases, it also hinders subsequent photolithographic focusing. Further, the film containing particles becomes a film containing foreign matter, which causes a deterioration in the performance of the film.
[0007]
A CVD that suppresses generation of particles is desired. In WSi CVD, there is a proposal to suppress the reaction between source gases by using a perforated plate in order to suppress generation of particles (for example, Patent Document 3).
[0008]
In the CVD of a ferroelectric film, if it is attempted to measure particles after film formation by light scattering in order to confirm the current state, light scattering occurs due to the roughness of the film surface itself, and accurate measurement becomes difficult. It becomes difficult to improve the film formation conditions while monitoring the state of particle generation.
[0009]
[Patent Document 1]
JP-A-10-67556 [Patent Document 2]
JP 2003-59917 A [Patent Document 3]
JP-A-2002-69650
[Problems to be solved by the invention]
An object of the present invention is to provide a chemical vapor deposition method capable of measuring particles by in-situ observation.
[0011]
It is another object of the present invention to provide a chemical vapor deposition apparatus capable of measuring particles by in-situ observation.
Here, “in situ” means within the same film forming apparatus and does not necessarily mean the same film forming chamber.
[0012]
Still another object of the present invention is to provide a chemical vapor deposition method capable of monitoring particles in a film forming gas.
Another object of the present invention is to provide a chemical vapor deposition apparatus capable of monitoring particles in a deposition gas.
[0013]
[Means for Solving the Problems]
According to one aspect of the present invention, (a) a step of vaporizing a film forming raw material liquid to form a raw material gas; and (b) carrying a substrate into a room equipped with a particle counter and forming a film containing the raw material gas. (C) introducing the gas onto the substrate while maintaining the gas at a temperature equal to or higher than the vaporization temperature and lower than the decomposition temperature; (c) measuring the number of particles on the substrate after the step (b); After the step (c), when the number of particles is equal to or less than a predetermined number, a step of raising the substrate temperature to the decomposition temperature or more and forming a thin film is provided.
[0014]
According to another aspect of the present invention, a substrate having a vaporizer for vaporizing a liquid material, a temperature-adjustable wall, a shower head connected to the vaporizer, and a temperature-adjustable substrate holding susceptor. A storage chamber, a particle counter coupled to the substrate storage chamber and capable of counting particles on a substrate disposed on the susceptor;
Is provided.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
In a ferroelectric memory device, when a ferroelectric film is formed, the film surface becomes rough, and it becomes difficult to measure particles on the film surface. In order to monitor particles, it is necessary to monitor the particles other than the surface of the formed film.
[0016]
The biggest cause of the particle generation is a phenomenon in which particles are generated before the film formation gas is introduced into the film formation chamber. In particular, in MOCVD, in a CVD apparatus having a raw material supply system in which a liquid-phase raw material is introduced into a vaporizer through a mass flow controller, is injected from a nozzle, and is evaporated on a heating surface, the nozzle of the vaporizer is a major cause of particle generation. Become. In addition, a cause of particle generation may occur in the middle of the pipe.
[0017]
When a large amount of particles are generated, it is desirable to perform maintenance processing such as cleaning the nozzle of the vaporizer or cleaning the entire pipe. The present inventor has considered a method for enabling measurement when a film formation gas introduced into a film formation chamber already contains particles.
[0018]
FIG. 1A schematically shows a configuration of a CVD apparatus used in a preliminary experiment. Each of the raw material containers RA, RB, and RC contains a raw material solution obtained by dissolving organic metals of Pb, Zr, and Ti at a constant concentration in a solvent. For example, the Pb raw material RA is Pb (THD) ₂ (THD is tetramethyl heptandionate) shown in FIG. 1B, and the Zr raw material RB is Zr (DMHD) ₄ (DMHD) shown in FIG. 1C. Is dimethyl heptandionate), and Ti (O-iPr) ₂ (THD) ₂ (iPr is isopropoxy) shown in FIG. 1D is used as the Ti raw material RC.
[0019]
Two pipes are inserted from above into the raw material container, one above the liquid level and one below the liquid level. When a pumping gas, for example, nitrogen gas, is fed into the pipe above the liquid level, the raw material solution is supplied from the other pipe.
[0020]
The number of raw material containers is not limited to three, and another raw material container may be provided. The solvent container SV contains only the same solvent as the raw material liquid. The solvent is also delivered at the same time as the raw material solution.
[0021]
The raw material solution and the solvent are introduced into the vaporizer VR via the mass flow controller MFC. In the vaporizer VR, each liquid is supplied from a nozzle onto a heating surface, and is vaporized on the heating surface to generate a deposition gas. The vaporization temperature of the PZT raw material is mainly 190 ° C. or higher, and the decomposition temperature is 300 ° C. or lower.
[0022]
The generated film forming gas is supplied to the pipe P1. The pipe P1 is connected to the pipe P2 via a valve V1. In the middle of the pipe P2 is merging point is provided with N ₂ gas for purging are merged. The pipe P2 is connected to the gas mixer GM.
[0023]
O ₂ gas is supplied to the heat exchanger HE via the mass flow control valve MFCV. After being heated to a predetermined temperature, it is sent to the pipe P3. The pipe P3 is connected to the gas mixer GM.
[0024]
In the gas mixer GM, the gas is ejected from the raw material pipe and the oxygen pipe that are arranged to face each other, and the gas collides with each other, whereby the raw material gas and the oxygen gas are mixed, and the mixed gas flows to the shower head SH. In the film forming chamber DC in which the wall temperature can be controlled, the mixed gas falls from the shower head SH onto the substrate SB.
[0025]
During film formation, the substrate SB is heated to, for example, 500 to 650 ° C. by a heater in the susceptor SC. The organometallic gas in the mixed gas that has dropped onto the substrate receives temperature energy from the substrate surface, is thermally decomposed, and forms a thin film on the substrate. The film forming gas not used for film formation is sucked into the pipe P5 via the exhaust port, rendered harmless via the cold trap CT, the exhaust system EV, and the harm removal device HL, and discarded in the atmosphere.
[0026]
Note that a valve V2 is connected to the pipe P1 in parallel with the valve V1, and is connected to the cold trap CT via the pipe P4. That is, by distributing a constant flow of the source gas to the pipes P2 and P4, it is possible to provide a film formation period and a pause period and prevent a change in the flow rate. N ₂ gas pipe connected to the middle of the pipe P4 is for purging.
[0027]
In the drawing, pipes P1 to P5 indicated by hatching indicate pipes heated to a temperature equal to or higher than the vaporization temperature and lower than the decomposition temperature so as to prevent liquefaction of the transported gas and maintain a stable state. The wall after film formation is also heated to a temperature equal to or higher than the vaporization temperature and lower than the decomposition temperature, thereby preventing liquefaction and decomposition of the film formation gas.
[0028]
The configuration described above is a configuration of a conventionally known CVD apparatus. In this experiment, a particle counter PC was attached to the film forming chamber DC. The particle counter PC can observe the particles on the substrate SB on the spot by using a laser beam.
[0029]
The substrate SB on which the lower electrode layer has been formed is loaded onto the susceptor SC in the film forming chamber DC. The surface of the lower electrode is smooth, and it is possible to measure particles. In this state, the temperature of the wall of the film forming chamber DC and the temperature of the susceptor SC are maintained at about the same temperature that is equal to or higher than the vaporization temperature of the source gas and lower than the decomposition temperature. Here, “about the same” refers to a temperature that can be regarded as the same in the CVD reaction.
[0030]
The film formation gas introduced into the film formation chamber DC flows down onto the substrate, but does not liquefy on the wall or the substrate, and neither decomposition nor film formation occurs. In this state, a film forming gas having the same composition is generated in the film forming chamber DC at the same vaporization temperature as when the film is actually formed, and the film forming gas is introduced at the same pressure and flow rate for a certain period of time. The difference from the actual film formation is that the substrate SB is not heated to the film formation temperature. If particles are mixed in the film-forming gas, the particles fall from the film-forming gas falling onto the substrate SB and adhere to the surface of the substrate SB.
[0031]
After the introduction of the deposition gas for a certain period of time, the supply of the deposition gas is stopped, and the number of particles on the substrate SB is measured by the particle counter PC. If the number of particles is small, there is a high possibility that good CVD film formation can be performed. When the number of particles is larger than a predetermined value, there is a high possibility that a film containing many particles will be formed even if the film is formed.
[0032]
An experiment was performed with a case where a PZT thin film was formed as an example. Pb raw material is Pb (THD) ₂ (THD is tetramethyl heptandionate), and Zr raw material is Zr (DMHD) ₄ (DMHD is dimethyl heptandionate) and Zr (THD) _4. As a raw material, Ti (iPr) ₂ (THD) ₂ (iPr) was used as isopropoxy). As the solvent, tetrahydrofuran THF and butyl acetate were used.
[0033]
A 6-inch silicon wafer was used as the substrate SB. During the supply of the deposition gas, the pressure in the deposition chamber DC was 5 Torr (667 Pa), the flow rate of the deposition gas was 2500 sccm, and the substrate temperature was 230 ° C.
Example 1
Using Zr (DMHD) ₄ as a Zr raw material and THF as a solvent, a film formation gas generated at a vaporization temperature of 260 ° C. is flowed into the film formation chamber for 2 minutes and 30 seconds. Was measured. About 1500 particles of 0.2 μm or more were measured.
[0034]
Generally, the wall temperature and the substrate temperature when the film is not formed are higher than the vaporization temperature and lower than the decomposition temperature, but in the case of the PZT film formation, approximately the same temperature of 230 ° C. ± 10 ° C. may be preferable. During film formation, the substrate temperature is raised to, for example, 600 ° C. ± 50 ° C.
[0035]
For comparison, a PZT film was formed by setting the substrate temperature to 580 ° C. and otherwise flowing the same film forming gas under the same conditions (raw material composition, solvent, vaporization temperature) as described above. A PZT film was formed on the surface of the substrate SB. The number of particles was measured on the surface of the formed film. The value measured as the number of particles of 0.2 μm or more was about 30,000. It is considered that rough irregularities on the substrate surface are erroneously counted as particles. The actual number of particles cannot be measured.
[0036]
The number of particles was measured while changing the flow rate of the film forming gas flowing into the film forming chamber, and the flow rate dependence of the number of particles was examined.
FIG. 2A is a graph showing measurement results of the number of particles with respect to a change in gas flow rate. When the gas flow rate was 1000 sccm, the number of particles was 10,000 or more. When the gas flow rate was increased to 2000 sccm, the number of particles dropped significantly below 10,000. But still more than 1,000. When the gas flow rate was increased to 4000 or 8000, the number of particles decreased to several hundreds. Furthermore, the ratio of particles having a relatively large particle diameter of 0.3 to 1 μm and a particle diameter of more than 1 μm with respect to all the particles was increased.
[0037]
From the results shown in FIG. 2A, it is found that the number of particles increases when the gas flow rate is small. A gas flow rate of 3000 sccm or more would be preferable.
Next, the number of particles was measured while changing the pressure in the film formation chamber, and the pressure dependence of the number of particles was examined.
[0038]
FIG. 2B is a graph showing a change in the number of particles with respect to a change in pressure in the film formation chamber. The pressure was changed to 267, 667, 1333 (Pa). The number of particles measured increased with increasing pressure. At a pressure of 1333 Pa, the number of particles was 10,000 or more. It is preferable that the pressure in the film forming chamber be 800 Pa or less.
[0039]
The main purpose is to observe the effects of the Zr raw material, the solvent, and the vaporization temperature in the vaporizer. As in Example 1, the flow rate is 2500 sccm, the pressure is 5 Torr (667 Pa), the substrate temperature is 230 ° C., and the Pb raw material is Pb ( THD) ₂ , Ti raw material Ti was (O-iPr) ₂ (THD) _2, and the number of particles was measured by changing at least one of the Zr raw material, the solvent, and the vaporization temperature in the vaporizer to those different from those in Example 1. .
[0040]
FIG. 2C shows the measurement results of five examples including Example 1.
Example 2
Compared with Example 1, the Zr raw material was changed from Zr (DMHD) ₄ to Zr (THD _4. ) The number of particles was increased by about twice.Zr (DMHD) ₄ was more preferable as the Zr raw material. Conceivable.
Example 3
Compared to Example 1, the solvent was changed to butyl acetate. The number of particles increased four times or more compared to Example 1 using THF as a solvent. THF would be preferred as the solvent over butyl acetate.
Examples 4, 5
As compared with Examples 1 and 3, the vaporization temperature was lowered to 190 ° C., and THF and butyl acetate were used as solvents. The number of particles was greatly reduced (1/5 or less) as compared with the case where the vaporization temperature was 260 ° C. The number of particles when using THF as a solvent was 1/5 or less of the number of particles when using butyl acetate as a solvent.
[0041]
Comparing THF as a solvent and butyl acetate, it can be seen that the number of particles is smaller when THF is used as a solvent. From the results of the vaporization temperatures of 260 ° C. and 190 ° C., it is estimated that the lower the vaporization temperature, the smaller the number of particles.
[0042]
From this measurement result, it is found that the use of Zr (DMHD) ₄ as the Zr raw material, the use of THF as the solvent, and the use of a vaporization temperature of 190 ° C. ± 10 ° C. are effective in reducing the number of generated particles. . The vaporization temperature will vary depending on the film forming material and the like, but it is preferably 190 ° C. or more and 300 ° C. or less. In Examples 1 to 5, the flow rate of the film forming gas was 2500 sccm. However, if the flow rate is increased to 3000 sccm or more, for example, 4000 sccm, the number of particles is expected to decrease.
[0043]
A CVD film forming method and a film forming apparatus based on the above experimental results will be described below.
FIG. 3A schematically shows the configuration of a CVD film forming apparatus. The transfer chamber T2, the two load lock chambers LLC1, LLC2, the film formation chamber DC, and the measurement chamber MC are connected so as to maintain airtightness. The transfer chamber T is provided with a magic hand, and can transfer wafers between the chambers under a reduced pressure atmosphere. The film formation gas can be supplied to the film formation chamber DC and the measurement chamber MC from the same growth gas pipe via the valves V11 and V12. The measurement room MC has almost the same configuration as the film formation room DC, but differs from the film formation room DC in that a particle counter is provided as shown in FIG.
[0044]
FIG. 3B schematically illustrates steps of a film forming method. When the process starts, the substrate is carried into the measurement room MC in step S1. The temperature of the susceptor on which the substrate is arranged and the temperature of the wall of the measurement chamber are set to the same temperature which is equal to or higher than the vaporization temperature and lower than the decomposition temperature.
[0045]
In step S2, the same deposition gas as in the case of forming a film is flowed over a substrate maintained at a temperature equal to or higher than the vaporization temperature and lower than the decomposition temperature for a certain period of time. For example, a deposition gas is flowed for 2 minutes and 30 seconds to attach particles to the substrate surface.
[0046]
In step S3, the supply of the deposition gas is stopped, and the number of particles attached to the substrate is measured.
In step S4, it is determined whether the number of particles on the substrate is equal to or less than a predetermined value. If it is equal to or less than the predetermined value, the process proceeds to step S5 according to the arrow of YES. If it is higher than the predetermined value, the process proceeds to step S8 according to the arrow of NO, unloads the substrate, returns to step S1, and loads another substrate into the measurement chamber.
[0047]
In step S5, the substrate whose number of particles is equal to or smaller than a predetermined value as a result of the measurement is moved to the film formation chamber DC. After that, another substrate is carried into the measurement chamber.
In step S6, the substrate carried into the film forming chamber DC is heated to a film forming temperature. For example, it heats to 500-650 degreeC. Except for the substrate temperature, the conditions are the same as when monitoring the particles.
[0048]
In step S7, a film forming gas is poured onto the heated substrate, and a dielectric film is formed by CVD. The film will be formed under the condition of low particle generation.
In step S8, the substrate on which the film formation has been completed is carried out. After that, the next substrate after the measurement is moved to the film formation chamber. If there is no substrate to be formed next, the process is terminated.
[0049]
If the state in which the number of particles is larger than the predetermined value continues in step S4, the film formation is interrupted, and the process proceeds to step S9 to perform maintenance. Although the case where particles are measured in the measurement chamber and a dielectric film is formed in the film formation chamber has been described, measurement and film formation can be performed in the same room. In this case, step S5 is omitted, and if YES, the process proceeds to step S6.
[0050]
FIG. 4 shows a configuration example of a semiconductor device formed using the above-described ferroelectric film. An element isolation region 102 is formed on the surface of the silicon substrate 101 by LOCOS, STI, or the like. A MOS transistor is formed in the active region defined by the element isolation region 102. A gate insulating film 103 is formed on the surface of the active region, and an n-type polysilicon gate electrode 104 is formed thereon. After patterning the gate electrode 104, ion implantation of an n-type impurity is performed to form the extension region 105.
[0051]
Thereafter, sidewall spacers 106 are formed on the side walls of the gate electrode 104, and ions are implanted using the gate electrode 104 and the sidewall spacers 106 as masks to form n ⁺ -type source / drain regions 107A, 107B, and 107C. Note that the source / drain region 107C has a symmetric configuration with the source / drain region 107A.
[0052]
After forming the MOS transistor structure, an interlayer insulating film 111 covering the gate electrode is formed. The interlayer insulating film 111 is formed, for example, by stacking a silicon oxide layer 111A and a silicon nitride layer 111B. The lower electrode 115 of the ferroelectric capacitor is formed on the interlayer insulating film 111 on the element isolation region. For example, a lower electrode 115 is formed by laminating a noble metal layer such as Pt and an oxide layer of a noble metal such as Ir and Ru.
[0053]
A ferroelectric film 116 is formed on the lower electrode 115 by a method according to the above-described embodiment. The upper electrode 117 is formed on the ferroelectric film 116. Since the upper electrode 117 is formed after the ferroelectric film is formed, the range of selection can be wider than that of the lower electrode. Known materials and structures can be used for the lower electrode and the upper electrode.
[0054]
After patterning the ferroelectric capacitor, its surface is covered with an insulating layer 118 such as silicon oxide. A wiring layer is formed on the surface of the insulating layer 118 and patterned to form a wiring 120A and a bit line 120B connecting the source / drain region 107A of the MOS transistor and the ferroelectric capacitor. After patterning the wiring, an insulating layer 121 such as silicon oxide is further formed on the surface. Thus, a non-volatile memory structure in which a MOS transistor and a ferroelectric capacitor are connected to both sides of one bit line can be created.
[0055]
Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. For example, various dielectric films other than PZT, in particular, ferroelectric films can be formed. The source gas will include at least one selected from the group consisting of Pb, Zr, Ti, La, Ca, Sr, Br, Ta, Bi, Ru, Ir, and Pt. In particular, in MOCVD using an organometallic raw material, the same effect as in the above embodiment can be expected. It will be apparent to those skilled in the art that various other modifications, improvements, and combinations are possible.
[0056]
Hereinafter, the features of the present invention will be additionally described.
(Supplementary Note 1) (1) (a) a step of vaporizing a film forming raw material liquid to form a raw material gas;
(B) carrying the substrate into a room equipped with a particle counter, introducing the film-forming gas containing the source gas at a temperature equal to or higher than the vaporization temperature and lower than the decomposition temperature, and introducing the film onto the substrate;
(C) after the step (b), measuring the number of particles on the substrate;
(D) after the step (c), when the number of particles is equal to or less than a predetermined number, increasing the substrate temperature to the decomposition temperature or more, and forming a thin film;
A chemical vapor deposition method comprising:
[0057]
(Supplementary note 2) (2) The chemical vapor deposition method according to supplementary note 1, wherein in the step (b), the temperature of the wall of the chamber and the temperature of the substrate are approximately the same.
(Supplementary note 3) (3) The chemical vapor deposition method according to Supplementary note 1 or 2, wherein the step (d) is performed in a different room from the steps (b) and (c).
[0058]
(Supplementary Note 4) (4) Supplementary notes 1 to 5 further including (e) after the step (c), when the number of the particles is larger than a predetermined number, replacing the substrate and returning to the step (b). 4. The chemical vapor deposition method according to claim 3.
[0059]
(Supplementary note 5) (5) The chemical reaction according to Supplementary note 4, further comprising: (f) after the step (e), when the number of the particles is larger than a predetermined number, performing a maintenance of the film forming apparatus. Vapor deposition method.
[0060]
(Supplementary note 6) Any one of Supplementary notes 1 to 5, wherein the source gas includes at least one selected from the group consisting of Pb, Zr, Ti, La, Ca, Sr, Ba, Ta, Bi, Ru, Ir, and Pt. 2. The chemical vapor deposition method according to claim 1.
[0061]
(Supplementary Note 7) (6) The supplementary notes 1 to 6, wherein the source gas contains an organometallic source gas of an element other than oxygen as a constituent element of PZT, and has a vaporization temperature of 190 ° C or higher and a decomposition temperature of 300 ° C or lower. The chemical vapor deposition method according to claim 1.
[0062]
(Supplementary Note 8) (7) The chemical vapor deposition method according to supplementary note 7, wherein the source gas includes tetrahydrofuran.
(Supplementary note 9) The chemical vapor deposition method according to supplementary note 7 or 8, wherein the substrate temperature in the step (b) is 230 ° C ± 10 ° C.
[0063]
(Supplementary note 10) The chemical vapor deposition method according to any one of Supplementary notes 7 to 9, wherein the substrate temperature in the step (d) is 600 ° C ± 50 ° C.
(Supplementary Note 11) (8) The chemical vapor deposition method according to any one of Supplementary Notes 7 to 10, wherein the flow rate of the film forming gas in the steps (b) and (d) is 3000 sccm or more.
[0064]
(Supplementary Note 12) (9) The chemical vapor deposition method according to any one of Supplementary Notes 7 to 11, wherein the pressure of the film forming gas in the steps (b) and (d) is 800 Pa or less.
(Supplementary note 13) The chemical vapor deposition method according to any one of Supplementary notes 7 to 12, wherein the substrate is a substrate on which a conductive layer for a lower electrode of a capacitor is deposited.
[0065]
(Supplementary Note 14) The chemical vapor deposition method according to any one of Supplementary Notes 7 to 13, wherein the step (d) forms a PZT film having a (111) orientation.
(Supplementary Note 15) (10) A vaporizer for vaporizing the liquid raw material,
A substrate storage chamber having a temperature-adjustable wall, a shower head connected to the vaporizer, and a temperature-adjustable substrate holding susceptor,
A particle counter coupled to the substrate storage chamber and capable of counting particles on the substrate disposed on the susceptor;
Chemical vapor deposition apparatus having:
[0066]
【The invention's effect】
Since the CVD film formation can be performed after confirming that the number of generated particles is small, the number of particles of the formed film can be estimated.
[0067]
Film formation can be performed under conditions with a small number of particles, and the yield can be improved. A highly reliable ferroelectric memory device can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a configuration of a CVD apparatus used in a preliminary experiment conducted by the inventor and a chemical structural formula of an organometallic raw material.
FIG. 2 is a graph and a table showing experimental results.
FIG. 3 is a schematic block diagram and a flowchart showing a CVD film forming apparatus and a film forming method according to an embodiment.
FIG. 4 is a cross-sectional view illustrating a configuration example of a semiconductor device manufactured according to an embodiment.
[Explanation of symbols]
R Raw material container SV Solvent container MFC Mass flow controller VR Vaporizer P Piping MFCV Mass flow control valve GM Gas mixer SH Shower head DC Film formation room SC Susceptor SB Substrate LLC Load lock chamber T Transfer room MC Measurement room V Valve

Claims (10)

(A) vaporizing a film-forming raw material liquid to form a raw material gas;
(B) carrying the substrate into a room equipped with a particle counter, introducing the film-forming gas containing the source gas at a temperature equal to or higher than the vaporization temperature and lower than the decomposition temperature, and introducing the film onto the substrate;
(C) after the step (b), measuring the number of particles on the substrate;
(D) after the step (c), when the number of particles is equal to or less than a predetermined number, increasing the substrate temperature to the decomposition temperature or more, and forming a thin film;
A chemical vapor deposition method comprising: 2. The chemical vapor deposition method according to claim 1, wherein in the step (b), the temperature of the wall of the chamber and the temperature of the substrate are about the same. The chemical vapor deposition method according to claim 1, wherein the step (d) is performed in a different room from the steps (b) and (c). 4. The method according to claim 1, further comprising: (e) after the step (c), when the number of particles is larger than a predetermined number, replacing the substrate and returning to the step (b). The chemical vapor deposition method as described. 5. The chemical vapor deposition method according to claim 4, further comprising: (f) after the step (e), when the number of the particles is larger than a predetermined number, performing a maintenance of the film forming apparatus. The said source gas contains the organometallic source gas of elements other than oxygen which is a constituent element of PZT, The vaporization temperature is 190 degreeC or more, The decomposition temperature is 300 degreeC or less, The Claims any one of Claims 1-5. Chemical vapor deposition method. 7. The chemical vapor deposition method according to claim 6, wherein the source gas includes tetrahydrofuran. 8. The chemical vapor deposition method according to claim 6, wherein the flow rate of the film forming gas in the steps (b) and (d) is 3000 sccm or more. The chemical vapor deposition method according to any one of claims 6 to 8, wherein the pressure of the film forming gas in the steps (b) and (d) is 800 Pa or less. A vaporizer for vaporizing the liquid raw material,
A substrate storage chamber having a temperature-adjustable wall, a shower head connected to the vaporizer, and a temperature-adjustable substrate holding susceptor,
A particle counter coupled to the substrate storage chamber and capable of counting particles on the substrate disposed on the susceptor;
Chemical vapor deposition apparatus having:

Images