JP2003324097A - Method for designing film formation device, method for film formation and method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a gas flow of uniform flow rate distribution along the outer periphery of a stage prepared in a film formation room of an MOCVD device. <P>SOLUTION: A method for designing a film formation device comprises; a 1st process for simulating the flow rate distribution of gas led from a shower head to flow in the film formation room while changing the ratio D<SB>1</SB>/D<SB>2</SB>of the outer diameter D<SB>1</SB>of the stage to the inner diameter D<SB>2</SB>of the film formation room to find out an equation σ=a×exp[b/D<SB>1</SB>/D<SB>2</SB>] (1) expressing the standard deviation σ of the gas flow rate distribution around the stage; and a 2nd process for determining the ratio D<SB>1</SB>/D<SB>2</SB>from the equation (1) so as to satisfy 3σ≤10%. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to the manufacture of semiconductor devices, and more particularly to the manufacture of non-volatile semiconductor devices having a ferroelectric film.

Semiconductor memory devices such as so-called DRAMs and SRAMs are widely used as high-speed main memory devices in information processing devices such as computers, but these are volatile memory devices and are stored when the power is turned off. The information given will be lost. On the other hand, a non-volatile magnetic disk device has been conventionally used as a large capacity auxiliary storage device for storing programs and data.

However, the magnetic disk device is large and mechanically fragile, consumes a large amount of power, and has a drawback that the access speed for reading and writing information is slow. On the other hand, recently, as a non-volatile auxiliary storage device, an EEP that stores information in the form of charges in a floating gate electrode
ROM or flash memory is often used. In particular, since a flash memory has a cell structure similar to that of a DRAM, it can be easily formed with a large integration density and is expected as a large-capacity storage device comparable to a magnetic disk device.

On the other hand, in an EEPROM or a flash memory, information is written by injecting hot electrons into a floating gate electrode through a tunnel insulating film, so that it takes a long time to write the information.
Further, there has been a problem that the tunnel insulating film is deteriorated when information is repeatedly written and erased. If the tunnel insulating film deteriorates, the writing or erasing operation becomes unstable.

On the other hand, information is taken as the spontaneous polarization of the ferroelectric film.
Ferroelectric memory device (hereinafter referred to as FeRAM)
Is proposed. In such FeRAM, individual memory
As in the case of DRAM, the memory cell transistor is a single
Dielectric in the memory cell capacitor consisting of MOSFET
The body film is made of PZT (Pb (Zr, Ti) O₃) Or PL
ZT ((Pb, La) (Zr, Ti) O₃),Moreover
SBT (SrBi₂Ta ₂O₃), Etc.
It is possible to integrate with high integration density.
It In addition, FeRAM is a ferroelectric capacitor when an electric field is applied.
Hot writing is used to control
EEPROM or FLA made by injecting lectron
Writing speed is 1000 times faster than Shure memory
It becomes faster and the power consumption is reduced to about 1/10.
It has the advantageous characteristics that Further tunnel oxide film
Since it does not need to be used, it has a long lifespan.
It is thought that it is possible to secure the number of rewrites of 100,000 times.

2. Description of the Related Art Conventionally, a ferroelectric film used for such an FeRAM is formed by a sol-gel method or a sputtering method. However, as semiconductor devices are miniaturized, these conventional methods provide coverage of fine steps. Is expected to be difficult. Under such circumstances, the CVD method is considered to be an indispensable technique as a technique for forming a ferroelectric film used in the next-generation FeRAM. In particular, when forming a ferroelectric film, it is necessary to supply a raw material containing a metal element such as Pb, Zr, or Ti. Therefore, the CVD method is different from the MOCVD method using an organometallic raw material of these metal elements. I have no choice.

FIG. 1 shows a conventional MOCVD method for a ferroelectric film.
1 shows a schematic configuration of an MOCVD apparatus 10 used for film formation by the method.

Referring to FIG. 1, in the MOCVD apparatus 10, Pb (DPM) ₂ from the raw material containers 12 ₁ , 12 ₂ and 12 _{3 is} removed.
(Lead bis (dipivaloylmethanate)), Zr (DP
M) ₄ (zirconium tetrakis (dimethyl heptadionate), Ti (PrO) ₂ (DPM) ₂ (titanium (diisoproxy) (dipivaloyl methanate)) and other solid organic metal raw materials such as THF (tetrahydrofuran) A liquid raw material obtained by dissolving in a solvent is supplied to the mixer 13 in the form of an organometallic raw material gas via the vaporizers 12a, 12b, 12c, and the raw material container is provided in the mixer 13. dopants from the 12 _4, vaporizer 12d
After being vaporized in, it is supplied.

These organometallic source gases are used in the mixer 1
Shower head 13S mixed in No. 3 and provided in the film forming chamber 11 via the valve 13A and the gas line 13B.
Is supplied together with the oxygen gas supplied from the oxygen gas line 13C. The organometallic raw material gas is mixed with the oxygen gas in the shower head 13S and supplied to the surface of the target substrate W held on the susceptor 11A. The metal-organic vapor phase raw material introduced into the film forming chamber 11 is
The surface of the substrate W to be processed is thermally decomposed, and as a result,
A ferroelectric film such as PZT is formed on the surface of the substrate W to be processed.

The film forming chamber 11 has a dry pump 1 through an exhaust line 11B, an APC 11b and a trap 11c.
4 as a result, the reaction product resulting from the thermal decomposition of the metal-organic vapor phase raw material in the film forming chamber 11 or the unreacted organic metal raw material that has not been thermally decomposed is an organic solvent component. Together with the exhaust line 11B,
After being treated by the dry pump 14 by the abatement device 15 provided on the downstream side of the pump 14, it is discharged to the outside.

Further, in the mixer 13, the APC1
A bypass line 16 connected to the dry pump 14 via 1b and the trap 11c is connected by a valve 16A. Also the vaporizer 12a~12d the liquid organic metal raw material supplied from each source container 12 ₁ to 12 _4, more solvent vessels 12 _5, an organic solvent such as THF optionally are added. Also, the gas line 13B
A purge gas line 13P is provided in the.

[0011]

On the other hand, when the ferroelectric film is formed by the MOCVD method as described above, it is required that the film thickness of the formed ferroelectric film is uniform. In order to form a ferroelectric film having such a uniform film thickness distribution, it is necessary to realize a uniform gas flow velocity distribution in the film forming chamber 11, especially along the surface of the substrate to be processed.

However, in operating the MOCVD apparatus, it is necessary to perform regular maintenance work, and in that case, the susceptor 11A may be removed from the film forming chamber 11. When the susceptor 11A removed in this way is mounted in the film forming chamber 11 again, it is inevitable that the central axis of the susceptor 11A is slightly eccentric to the central axis of the film forming chamber 11 by about 2 mm at the maximum.

When the susceptor 11A is thus eccentric in the film forming chamber 11, when the process gas containing the metal-organic vapor phase raw material and oxygen is introduced into the film forming chamber 11 from the shower head 13S, the process gas is When flowing to the exhaust port 11B provided below the susceptor 11A, the eccentricity of the susceptor 11A may result in uneven flow to one side of the susceptor 11A. When such a state occurs, the film thickness of the ferroelectric film formed on the susceptor 11A becomes non-uniform, and there arises a problem that the film thickness of the ferroelectric film is large on one side of the wafer and small on the other side. .

Therefore, it is a general object of the present invention to provide a novel and useful method for designing a film forming apparatus, a film forming method using the film forming apparatus, and a method for manufacturing a semiconductor device, which solve the above problems. And

A more specific object of the present invention is to provide a method of designing a film forming apparatus capable of forming a film with a uniform film thickness distribution even if the susceptor is slightly decentered in the film forming chamber, and to use the film forming apparatus. Another object is to provide a film forming method and a semiconductor device manufacturing method.

[0016]

The present invention solves the above-mentioned problems.
A film forming chamber, a susceptor provided substantially coaxially in the film forming chamber for holding a substrate to be processed, an exhaust system for exhausting the film forming chamber, and a susceptor held in the film forming chamber on the susceptor. A method for designing a film forming apparatus comprising a shower head provided so as to face a target substrate to be processed, the gas being introduced into the film forming chamber from the shower head and flowing in the film forming chamber. Is simulated while changing the ratio D ₁ / D ₂ of the outer diameter D _{1 of the} susceptor and the inner diameter D _{2 of the} film forming chamber, and an equation expressing the standard deviation σ of the gas flow velocity distribution around the susceptor. From the first step of obtaining σ = a · exp [b · (D ₁ / D ₂ )] (1) and the above equation (1), the ratio D _1
Second , determining / D ₂ so as to satisfy 3σ ≦ 10%
And a ferroelectric film forming method using a film forming apparatus designed by such a designing method, or by such a designing method. This is solved by a method for manufacturing a semiconductor device using a film forming apparatus.

According to the invention, the outer diameter D _{1 of the} susceptor is
And the inner diameter of the film forming chamber D ₂ are determined so that the 3σ value of the flow velocity distribution given by the equation (1) is 10% or less, the gas around the susceptor is slightly eccentric. It is possible to make the flow velocity distribution uniform, and as a result, it is possible to form a very uniform ferroelectric film. At that time, in the present invention, the susceptor is allowed to have an eccentricity of about 2 mm. Therefore, even when the susceptor is removed from the film forming chamber for maintenance or the like and then reassembled, the distribution of the gas flow velocity does not significantly change. The formation of a uniform ferroelectric film is guaranteed.

The present invention is particularly applicable to Pb as the organometallic raw material.
(DPM) ₂ , Zr (DPM) ₄ and Ti (iPrO)
₂ (DPM) ₂ or Pb (DPM) ₂ , Zr (DMH
D) ₄ and Ti (iPrO) ₂ (DPM) ₂ are used to form a PZT film.
M) ₂ , Sr (DPM) ₂ and Ti (iPrO) ₂ (D
It is useful in forming a BST film using PM) ₂ or forming an SBT film using Sr (DPM) ₂ , Bi (DPM) ₃ and Ta (O-Et) ₄ as the organic metal raw material. is there. These organometallic raw materials are sent to a vaporizer in a form of being dissolved in an organic solvent such as THF, and the vapor thus formed is supplied to the film forming chamber.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 2 (A),
(B) shows the result of a simulation performed by the inventor of the present invention on the distribution of the gas flow in the film forming apparatus 10 of FIG. 1, particularly in the film forming chamber 11. However, as shown in FIG.
In the simulation of (B), as shown in FIG. 3, the film forming chamber 11 has a cylindrical shape with an inner diameter D2, and the susceptor 1
1A has a cylindrical shape with an outer shape D1, and the susceptor 11A has an eccentricity of δ with respect to the central axis of the film forming chamber 11.

Referring to FIG. 3, the shower head 1
The gas introduced from 3S flows along the surface of the substrate W to be processed on the susceptor 11A, and then the susceptor 11A.
Exhaust port 11B through the gap between A and the film forming chamber 11
Flows to.

In FIG. 2A, the inner diameter D2 of the film forming chamber 11 is set to 2
96mm, and the outer shape of the susceptor 11A is 290mm
(= D2 × 0.98) and the eccentricity δ is 2m
The case of m is shown. In this case, the susceptor 11
The gap G between A and the inner wall of the film forming chamber 11 is 3 mm on average, 2 mm at maximum, and 1 mm at minimum.

Referring to FIG. 2A, in such a state, the gas flow formed in the film forming chamber 11 is biased, and the gap W surrounded by a circle in the drawing is maximized. It was found that the flow velocity increased especially near the part. Along with this, the gas flow velocity flowing through the gap also becomes imbalanced,
It was calculated that the flow velocity ratio was 0.76 between the maximum gap and the minimum gap.

On the other hand, in FIG. 2B, the inner diameter D2 of the film forming chamber 11 is 302 mm, and the outer diameter of the susceptor 11A is 2.
The case is shown in which it is set to 90 mm (= D2 × 0.96) and the eccentricity amount δ is set to 2 mm. In this case, the distance G between the susceptor 11A and the inner wall of the film forming chamber 11 is 6 on average.
mm, the maximum is 8 mm, and the minimum is 4 mm.

Referring to FIG. 2B, the gas flow formed in the film forming chamber 11 is biased even in this state, and the portion surrounded by a circle and having the maximum gap G is shown in FIG. Especially in the vicinity, the flow velocity becomes large. Accordingly, the flow velocity ratio between the maximum gap and the minimum gap was calculated to be 0.30.

The deviation of the flow velocity as shown in FIGS. 2A and 2B is caused by the deviation of the film thickness in the ferroelectric film formed on the substrate W to be processed held on the susceptor 11A. Will occur.

Such a bias in the flow velocity is caused by the susceptor 1
Although it can be solved by strictly reducing the eccentricity amount δ between 1A and the film forming chamber 11 to zero, it is actually used in MOCVD.
In the apparatus, the susceptor 11A may be removed from the film forming chamber 11 for maintenance or the like, and it is difficult to strictly set the eccentricity amount δ to zero.

Under these circumstances, in the conventional MOCVD apparatus, it is unavoidable that the ferroelectric film formed on the wafer has some deviation in film thickness.

On the other hand, the inner diameter of the film forming chamber 11 is 387 m.
m, the outer diameter of the susceptor 11A is 290 mm, and the eccentricity δ
FIG. 4 shows the result of simulating the gas flow in the film forming chamber 11 when the thickness was set to 2 mm. Therefore, in the example of FIG. 4, the gap between the susceptor 11A and the film forming chamber 11 is 50.5 m at the maximum along the outer circumference of the susceptor 11A.
m, and the minimum value is 46.5 mm.

It can be seen from FIG. 4 that there is no bias in the distribution of the gas flow and that an axially symmetrical gas flow is formed around the susceptor 11A.

FIG. 5 shows the standard deviation σ of the gas flow velocity distribution around the susceptor 11A in the film forming chamber 11 of FIG.
The relationship between the diameter ratio D ₁ / D ₂ and the diameter ratio D ₁ / D ₂ is shown by simulation with the eccentricity δ as a parameter.

Referring to FIG. 5, between the standard deviation σ and the diameter ratio D ₁ / D ₂ , the equation σ = a · exp [b · (D ₁ / D ₂ ) with a and b as constants. ] It can be seen that the relationship represented by (1) exists.

Therefore, referring to FIG. 5, around the susceptor 11A.
The gas flow velocity distribution at is sufficiently uniform and its 3σ value is 1
If the condition of 0% or less is imposed, the diameter when the eccentricity is 2 mm
Ratio D ₁/ D₂Is 0.856 or less (D₁/ D₂≦ 0.856)
I know that it must be. The eccentricity is 1 mm
In the case of, the diameter ratio D₁/ D₂Is 0.885 or less (D ₁
/ D₂I know that it must be ≤ 0.885)
It When the eccentricity is ideally 0.0 mm, σ
= 0, the above conditions are satisfied regardless of the diameter ratio.
It

FIG. 6 shows the case of δ = 1 mm and δ = 2 in FIG.
In the case of mm, the relationship between the diameter D _{2 of} the film forming chamber and the diameter D ₁ of the susceptor satisfying the condition 3σ ≦ 10% is shown.

From FIG. 6, δ = 1 mm or δ = 2 mm
By using D ₁ and D ₂ that fall in a region above the straight line of, it becomes possible to form a gas flow having a uniform flow velocity distribution in the film forming chamber 11 along the outer periphery of the susceptor 11A. .

FIG. 7 is a flow chart showing a method of designing a film forming apparatus according to the first embodiment of the present invention based on the above findings.

Referring to FIG. 7, the maximum eccentricity δ expected in the film forming apparatus is set in step 1, then the gas flow is simulated in step 2, and the above relational expression σ = a · exp [b ・ (D ₁ /
D ₂ )] is required. This simulation can be performed using known software such as FLUENT, STAR-CD, and PHOENICS.

Next, in step 3, by imposing the condition that 3σ of the flow velocity distribution along the outer circumference of the susceptor 11A is 10% or less, preferable D ₁ / D ₂ in step 4 is obtained.
The ratio is required.

Based on the D ₁ / D ₂ ratio thus determined, an MOCVD apparatus similar to that described with reference to FIG. 1 is manufactured. In such a MOCVD apparatus, the susceptor 1
Since a sufficient space is secured around 1A, a uniform gas flow is formed on the wafer surface held on the susceptor 11A, and a ferroelectric film such as PZT, BST, or SBT is formed to have a uniform film thickness. Can be formed.

Incidentally, in FIG. 6, if the inner diameter D ₂ of the film forming chamber 11 is increased without limit, the flow velocity distribution in the film forming chamber 11 will certainly improve. Would increase the volume and would require the use of expensive and powerful exhaust systems and abatement devices. Further, the area occupied by the film forming apparatus also becomes large, which causes a problem when configuring the film forming apparatus having a cluster configuration together with other film forming apparatuses.

From the above, considering the value of 1 mm or 2 mm as the actually considered eccentricity δ, the inner diameter D ₂ of the film forming chamber 11 and the outer diameter D _{1 of the} susceptor 11A are straight lines shown in FIG. It is preferable to decide to get on.

In the film forming apparatus of the present invention, since the processing gas flows along the surface of the substrate to be processed on the susceptor 11A, a single wafer type cluster type processing apparatus can be easily constructed. [Second Embodiment] Next, a second embodiment of the present invention using the MOCVD apparatus having the structure of FIG. 1 and having the inner diameter of the film forming chamber 11 and the outer diameter of the susceptor 11A optimized according to the previous embodiment is used. The manufacturing process of the FeRAM according to the embodiment will be described.

FIG. 8 shows the FeR according to the second embodiment of the present invention.
The structure of AM30 is shown.

Referring to FIG. 8, the FeRAM 30 has Si having an element region defined by an element isolation structure 30A.
A gate electrode 33 formed on the substrate 31 and corresponding to the active region on the Si substrate 31 via a gate insulating film 32, and the Si substrate 31 on both sides of the gate electrode 33. Source and drain diffusion regions 31A and 31B formed therein are formed.

Further, an interlayer insulating film 34 is formed on the Si substrate 31, and a conductive plug 34A electrically connected to one diffusion region 31A is buried in the interlayer insulating film 34. There is. Further, a bit line BL electrically connected to the diffusion region 31A via the plug 34A is formed on the interlayer insulating film 34.

An interlayer insulating film 35 is further formed on the interlayer insulating film 34 on which the bit line BL is formed. The interlayer insulating film 35 penetrates the interlayer insulating film 34 and the other diffusion region 31B. Conductive plug 35 electrically connected to
B is embedded.

A lower capacitor electrode 36 having a structure in which a barrier metal layer and a lower electrode layer are sequentially stacked is formed on the interlayer insulating film 35 in which the conductive plug 35B is embedded. In the lower capacitor electrode 36, the lower electrode layer is composed of an Ir layer or a Pt layer. When a Pt layer is used as the lower electrode layer, an Ir layer is formed as a barrier metal layer, and an IrOx layer, for example, is formed as an adhesion layer on the Ir layer. The Pt lower electrode layer is formed on the IrOx layer thus formed. On the other hand, when the lower electrode layer is an Ir layer, the lower capacitor electrode 36 is composed of a single Ir layer. FIG. 8 shows a case where an Ir layer is used as the lower capacitor electrode 36.

PZ is formed on the lower capacitor electrode 36.
A capacitor dielectric film 37 made of T is formed,
An upper capacitor electrode 38 made of Pt, Ir, or IrOx is formed on the capacitor dielectric film 37. The lower capacitor electrode 36, the ferroelectric capacitor dielectric film 37 and the upper capacitor electrode 38 are
This constitutes a ferroelectric capacitor of FeRAM.

Next, a manufacturing process of the FeRAM of FIG. 8 will be described with reference to FIGS. 9 (A) to 12 (H).

Referring to FIG. 9A, the Si substrate 3
The element isolation structure 30A is formed in 1 by, for example, a shallow trench method to define an element region.

Then, on the element region defined by the element isolation structure 30A, the gate electrode 33 formed via the gate insulating film 32 and the gate are formed in the same manner as in the usual MOS transistor formation method. Diffusion regions 31 formed in the Si substrate 31 on both sides of the electrode 33.
A and 31B are formed to form a memory cell transistor of FeRAM.

Next, in the step of FIG. 9B, a silicon oxide film is deposited on the Si substrate 31 on which the memory cell transistors are formed by, for example, the CVD method to form the interlayer insulating film 34. Further, the surface of the interlayer insulating film 34 thus formed is polished by CMP (Chemical Mechanical Polishing) or the like to flatten the surface of the interlayer insulating film 34.

Further, in the step of FIG. 9B, the interlayer insulating film 34 is formed by the lithography technique and the etching technique.
Contact hole 34a reaching the diffusion region 31A
And the interlayer insulating film 3 is formed in the step of FIG.
A tungsten (W) film is deposited on the surface 4 by a sputtering method or the like so as to fill the contact hole 34a, and then polished by a CMP method until the surface of the interlayer insulating film 34 is exposed. As a result, the contact hole 34
A conductive plug 34A embedded in a is formed in a state of being electrically connected to the diffusion region 31A.

In the step of FIG. 9C, a W film is further deposited on the interlayer insulating film 34 by a sputtering method or the like, and is patterned by a lithography technique and an etching technique. A bit line BL connected to the diffusion region 31A via the sex plug 34A is formed.

Next, in the step of FIG. 10D, for example, C is formed on the interlayer insulating film 34 on which the bit BL line is formed.
A silicon oxide film is deposited by the VD method to form another interlayer insulating film 35. Further, a contact hole 35b penetrating the underlying interlayer insulating film 34 and reaching the diffusion region 31B is formed in the interlayer insulating film 35 by the lithography technique and the etching technique.

Further, in the step of FIG. 10E, after depositing a W film on the interlayer insulating film 35 by, for example, a sputtering method or the like, polishing is performed by a CMP method until the surface of the interlayer insulating film 35 is exposed, and a contact is made. Conductive plug 3 filling hole 35b and electrically connected to diffusion region 31B
5B is formed.

In the step of FIG. 10E, the barrier metal forming the lower capacitor electrode 36 and the lower electrode layer 360 are further deposited on the interlayer insulating film 35 by the sputtering method.

Next, in the step of FIG. 11F, the MOCVD apparatus 20 of FIG. 3 is used to form Pb (DPM) ₂ , Zr (DPM) ₄ and Ti (iPr) on the lower electrode layer 360.
O) ₂ (DPM) ₂ , or Pb (DPM) ₂ , Zr (D
The PZT film 37 is formed by the MOCVD method using an organometallic raw material such as MHD) ₄ and Ti (iPrO) ₂ (DPM) _2.
Form 0. At that time, in this embodiment, the decomposition cylinder 26A of the MOCVD apparatus is controlled to a temperature of 300 to 450 ° C., preferably 300 to 400 ° C., and the decomposition cylinder 26A is controlled.
Suppress precipitation due to decomposition of the organometallic raw material inside.

Further, in the step of FIG. 11G, a Pt, Ir, or IrOz film is deposited on the PZT film 370 by a sputtering method, and the upper electrode layer 380 is formed.
To form.

Finally, in the step of FIG. 12H, the films 360 to 360 are formed by lithography and etching techniques.
The lower capacitor electrode 36, the ferroelectric capacitor insulating film 37 and the upper capacitor electrode 37 are formed by patterning 380 to obtain the structure described above with reference to FIG.

The present invention has been described above with reference to the preferred embodiments, but the present invention is not limited to the above specific embodiments, and various modifications and changes can be made within the scope of the claims. It is possible.

[0061]

According to the present invention, a processing gas is introduced from a shower head facing a susceptor holding a substrate to be processed, and the processing gas is exhausted through the outer circumference of the susceptor. By setting the inner diameter of the chamber and the outer diameter of the susceptor optimally in consideration of the eccentric amount of the susceptor, it becomes possible to realize a uniform gas flow velocity distribution along the outer circumference of the susceptor. As a result, it becomes possible to uniformly form a ferroelectric film such as PZT, BST, or SBT on the surface of the substrate to be processed.

[Brief description of drawings]

FIG. 1 MOCV used in conventional ferroelectric film formation
It is a figure which shows the structure of D apparatus.

2A and 2B are diagrams showing a gas flow state in a film forming chamber used in the MOCVD apparatus of FIG.

FIG. 3 is a diagram showing a structure and parameters of a film forming chamber which is a basis of the simulation of FIG.

FIG. 4 is a diagram showing a gas flow when the design of the film forming chamber in FIG. 3 is changed.

5 is a diagram showing a relationship between a variation of a flow velocity distribution of a gas flow along an outer circumference of a susceptor and a ratio of a film forming chamber inner diameter to a susceptor outer diameter in the film forming chamber of FIG.

FIG. 6 is a diagram showing the relationship between the outer diameter of the susceptor and the inner diameter of the film forming chamber that minimizes the flow velocity distribution of the gas flow along the outer circumference of the susceptor.

FIG. 7 is a diagram illustrating a design process of the film forming apparatus according to the first embodiment of the present invention.

FIG. 8 is a diagram showing a structure of an FeRAM according to a second embodiment of the present invention.

9A to 9C are views (No. 1) showing a manufacturing process of the FeRAM in FIG.

10 (D) to (E) are views (No. 2) showing a manufacturing process of the FeRAM of FIG. 8.

11 (F) to (G) are views showing a manufacturing process of the FeRAM in FIG. 8 (No. 3).

12H is a view (No. 4) showing the manufacturing process of the FeRAM in FIG. 8; FIG.

[Explanation of symbols]

10 MOCVD device 11 film forming chamber 11A susceptor 11B exhaust line 11b APC 11c trap 12 vaporizers 12 _{1 to} 12 ₄ raw material supply part 13B raw material gas line 13C oxidizing gas line 13P purge line 13S shower head 14 dry pump 15 abatement device 16 vent Line 16A Vent valve 30 FeRAM 30A Element isolation structure 31 Si substrates 31A and 31B Diffusion region 32 Gate insulating film 33 Gate electrodes 34 and 35 Interlayer insulating film 36 Lower capacitor electrode 37 Ferroelectric capacitor insulating film 38 Upper capacitor electrode 360 Lower electrode layer 370 Ferroelectric film 380 Upper electrode layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Maruyama             4-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa             No. 1 within Fujitsu Limited (72) Inventor Masaki Kurasawa             4-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa             No. 1 within Fujitsu Limited F-term (reference) 4K030 AA11 AA14 BA01 BA22 BA42                       JA03 JA07 JA12 KA08                 5F045 BB02 DP03 DQ10 EF05

Claims (10)

[Claims] 1. A film forming chamber, a susceptor which is provided substantially coaxially in the film forming chamber and holds a substrate to be processed, an exhaust system for exhausting the film forming chamber, and the inside of the film forming chamber, A method for designing a film forming apparatus comprising a shower head provided so as to face a substrate to be processed held on the susceptor, wherein the shower head is introduced into the film forming chamber to form the film. The flow velocity distribution of the gas flowing in the chamber was simulated while changing the ratio D ₁ / D ₂ of the outer diameter D _{1 of the} susceptor and the inner diameter D _{2 of the} film forming chamber to obtain the gas flow velocity distribution around the susceptor. From the first step of obtaining the expression σ = a · exp [b · (D ₁ / D ₂ )] (1) representing the standard deviation σ, and from the above expression (1), the ratio D ₁ / D ₂ is set to 3σ. A second step of determining so as to satisfy ≦ 10%. Design method. 2. In the first step, the simulation is performed by setting a maximum value of a deviation of a central axis of the susceptor with respect to a central axis of the film forming chamber to 2 mm. 1. The method for designing a film forming apparatus according to 1. 3. In the first step, the simulation is performed by setting a maximum value of a deviation of a central axis of the susceptor with respect to a central axis of the film forming chamber to 1 mm. 1. The method for designing a film forming apparatus according to 1. 4. The inner diameter D _{2 of the} film forming chamber is set to 300 mm or more, and the outer diameter D _{1 of the} susceptor is set to 282 mm or less. A method for designing the film forming apparatus described. 5. A method of forming a ferroelectric film using a film forming apparatus designed by the designing method according to claim 1, wherein the film forming chamber is evacuated. And a step of forming an organometallic vapor phase raw material by vaporizing the organometallic raw material, and a step of introducing the organometallic vapor phase raw material together with oxygen gas into the film forming chamber from the shower head. And a film forming method. 6. The organometallic raw material is Pb (DPM) ₂ ,
Zr (DPM) ₄ and Ti (iPrO) ₂ (DPM) ₂
The film forming method according to claim 5, wherein the film forming method comprises: 7. The organometallic raw material is Pb (DPM) ₂ ,
Zr (DMHD) ₄ and Ti (iPrO) ₂ (DPM)
Consists _2, the film forming method according to claim 5, characterized in that it is dissolved in THF solvent. 8. The organometallic raw material is Ba (DPM) ₂ ,
Sr (DPM) ₂ and Ti (iPrO) ₂ (DPM) ₂
The film forming method according to claim 5, wherein the film forming method comprises: 9. The organometallic raw material is Sr (DPM) ₂ ,
Bi (DPM) ₃ and Ta (O-Et) ₄ and T
6. Dissolved in an HF solvent, characterized in that
The film forming method described. 10. A method of manufacturing a semiconductor device, comprising a step of forming a ferroelectric film using a film forming apparatus designed by the design method according to claim 1. The step of forming the ferroelectric film includes the step of exhausting the film forming chamber, the step of forming an organometallic vapor phase raw material by vaporizing the organometallic raw material, and the film forming of the organometallic vapor phase raw material together with oxygen gas. A method of manufacturing a semiconductor device, comprising the step of introducing the shower head into the chamber.