JP4759916B2 - Processing equipment - Google Patents

Description

The present invention is related to apparatus for forming a thin film with respect to an object to be processed such as a semiconductor wafer.

Ferroelectric memory devices are attracting attention as next-generation nonvolatile memories that replace conventional flash memories and the like, and are actively researched and developed. This ferroelectric memory element is a semiconductor element in which a ferroelectric capacitor in which a ferroelectric film is interposed between two electrodes is used for a memory cell. Ferroelectrics have [spontaneous polarization], that is, once a voltage is applied, there is a characteristic (hysteresis) that charges remain even if the voltage is reduced to zero. It is memory.
As a ferroelectric film of such a ferroelectric memory element, a Pb (Zr _x , Ti _1-x ) O ₃ (hereinafter referred to as PZT) film is widely used.

In order to form such a ferroelectric film, a plurality of organometallic compounds containing a metal element are gasified, and simultaneously supplied into a processing vessel, for example, by CVD (Chemical Vapor Deposition) film formation. A physical thin film is formed.
The organometallic compound that is the raw material is often present in liquid or solid form at normal temperature and normal pressure. For example, when the raw material is solid at normal temperature and normal pressure, the solid raw material gas is heated and sublimated to form a raw material gas. The raw material gas is flow-controlled by a high-temperature mass flow controller and supplied into a processing vessel that can be evacuated to form a metal oxide thin film on the semiconductor wafer.
Similarly, when the raw material is liquid at normal temperature and normal pressure, the liquid raw material is heated and vaporized to form a raw material gas, and the flow rate of the raw material gas is controlled by a high-temperature mass flow controller so that it can be evacuated. A metal oxide thin film is formed on the semiconductor wafer by supplying it into the processing vessel.

  In another method when the raw material is solid at normal temperature and pressure, this solid raw material is dissolved in an appropriate solvent to form a liquid raw material, and this liquid raw material is pumped with a pressurized gas and this flow rate is adjusted. The liquid raw material is controlled and supplied to the vaporizer, and the liquid raw material is vaporized by the carrier gas in the vaporizer to form the raw material gas, and this raw material gas is supplied into a processing vessel that can be evacuated to the semiconductor wafer. A metal oxide thin film is formed on the substrate (see Patent Document 1 and Patent Document 2). Moreover, in order to remove mist and particles in the raw material gas, a technique in which a filter is provided in the gas passage is also known (see Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6).

Japanese Patent Laid-Open No. 11-323560 (page 5-6, FIG. 1) JP 2000-260766 A JP-A-6-310444 JP 2000-150497 A Japanese Patent Laid-Open No. 10-195658 JP-A-11-269653

  By the way, as described above, the raw material of the organometallic compound is vaporized or sublimated and supplied in a gas state. At this time, a part of the raw material gas may adhere to or desorb from the inner wall of the gas passage. . In such a case, there is a problem that the source gas attached to the inner wall of the pipe separates and reaches the wafer separately from the source gas whose flow rate is controlled, and the film quality deposited on the wafer surface deteriorates. Here, the specific content of film quality deterioration is that the reproducibility of the film thickness deteriorates or the reproducibility of the composition ratio deteriorates. Such a film quality deterioration phenomenon appears remarkably in processes in which film quality control at the interface with the wafer greatly affects the entire film characteristics, such as a PTO (lead titanate) nucleation process.

  In addition, as described above, the liquid raw material in which the solid raw material is dissolved in an appropriate solvent is supplied after being vaporized by the carrier gas in the vaporizer. In this case, the liquid raw material is completely vaporized and gasified. If possible, there will be no problem, but depending on the conditions at the time of vaporization, the liquid raw material is not completely vaporized, and a part of the liquid raw material is supplied into the processing vessel in a mist state, that is, mixed in the raw material gas. The case will occur. In such a case, the mist has a diameter of only about 1 to 2 μm, but if the film formation process is performed while the mist is attached to the wafer surface, the film quality deposited on the wafer surface deteriorates. there were. Here, the specific content of film quality deterioration is that the yield of semiconductor products obtained from the film deteriorates.

Furthermore, a part of the raw material gas adhering to the inner wall of the gas passage may change in quality and become a film, which may peel off and become particles. The generated particles are mixed into the raw material gas and enter the processing container. There are cases where it reaches. Although this particle has a diameter of only 1 μm or less, there is a problem in that the film quality deposited on the wafer surface deteriorates when the film forming process is performed while the particle is attached to the wafer surface. Here, the specific content of film quality deterioration is that the yield of semiconductor products obtained from the film deteriorates. Such a particle generation phenomenon is prominent particularly when the distance of the pipe (gas passage) is long or when the internal surface area of the component (surface area in contact with the raw material gas in a part such as a pipe or a valve) is large.
In addition, when a filter is simply provided in the gas passage as in Patent Documents 3 to 6, the raw material gas always flows through the filter, resulting in a problem that the maintenance frequency increases.

The present invention has been devised to pay attention to the above problems and to effectively solve them.
The object of the present invention is to provide a removing means for removing particles and mist in the raw material gas when the raw material is vaporized or sublimated and supplied as a raw material gas, and the maintenance life of the removing means is reduced and this long service life is provided. An object of the present invention is to provide a processing device that can be made simple.

An object of the present invention is to provide a process equipment which can also prevent the film quality by supplying stable material gas is deteriorated.
An object of the present invention is to provide two sets of bypass passages when vaporizing or sublimating a raw material and supplying it as a raw material gas, so that the raw material gas adhering to the inner wall of the pipe (gas passage) is desorbed and reaches the wafer. the invention is to provide a process equipment which can prevent.
Another object of the present invention is to provide a processing apparatus capable of preventing particles and mist of the raw material from being introduced into the processing container by providing a removing means in the gas passage when supplying the raw material gas. Is to provide a place. In addition, when both are combined, a higher quality film can be stably supplied.

The related art of the present invention includes a raw material gas supply system configured to supply a raw material gas into a processing container through a gas passage, a processing container having a mounting table on which a target object is mounted, and the processing container In a processing apparatus having a vacuum exhaust system for evacuating the interior, a first bypass passage for bypassing the processing container is communicated between the gas passage and the vacuum exhaust system. In order to switch the flow, a first switching valve is interposed in the gas passage, and a second switching valve is interposed in the first bypass passage, and the gas passage and the first bypass passage are connected to each other. The processing apparatus is characterized in that a removal means for removing particles and / or mist contained in the raw material gas is interposed in the gas passage on the downstream side of the branch point.

  As described above, since the removing means is provided in the gas passage downstream of the branch point of the first bypass passage of the gas passage through which the raw material gas flows, particles and / or mist contained in the raw material gas is removed. In addition, it is possible to prevent particles and mist from flowing into the processing container. Therefore, it is possible to send a high-quality raw material gas and prevent deterioration of the film quality. Further, since the source gas does not flow through the removing means when the source gas flows through the first bypass passage, the maintenance frequency can be reduced.

In this case, for example, the removing means is provided on the downstream side of the first switching valve.
For example, the removal means is provided on the upstream side of the first switching valve.
According to the first aspect of the present invention, there is provided a raw material gas supply system configured to supply a raw material gas into a processing container via a gas passage, a processing container having a mounting table on which an object to be processed is mounted, and the processing In a processing apparatus having an evacuation system for evacuating the inside of the container, a first bypass passage for bypassing the processing container is communicated between the gas passage and the evacuation system, and the source gas In order to switch the flow of gas, a first switching valve is interposed in the gas passage, and a second switching valve is interposed in the first bypass passage, and a gas passage on the downstream side of the first switching valve And a first bypass passage on the downstream side of the second switching valve is formed, a second bypass passage is formed, and a third switching is made to a gas passage on the downstream side of the branch point of the second bypass passage. A valve is interposed, and the second A fourth switching valve is provided in the bypass passage, and particles and / or mist contained in the source gas are removed in the gas passage between the first switching valve and the branch point of the second bypass passage. In order to stabilize the flow rate of the raw material gas, the first switching valve and the third switching valve are both closed and the second switching valve is opened. When purging the gas passage between the first switching valve and the branch point of the second bypass passage, both the second switching valve and the third switching valve are closed and the first switching is performed. When both the valve and the fourth switching valve are opened and the source gas is allowed to flow to the processing vessel for film formation, both the second switching valve and the fourth switching valve are closed and the First off A processing apparatus characterized by being configured to provide a valve control unit which are both opened valve and the third switching valve.

According to a second aspect of the present invention, there is provided a raw material gas supply system configured to supply a raw material gas into a processing container via a gas passage, a processing container having a mounting table on which an object to be processed is mounted, and the processing In a processing apparatus having an evacuation system for evacuating the inside of the container, a first bypass passage for bypassing the processing container is communicated between the gas passage and the evacuation system, and the source gas In order to switch the flow of gas, a first switching valve is interposed in the gas passage, and a second switching valve is interposed in the first bypass passage, and a gas passage on the downstream side of the first switching valve And a first bypass passage on the downstream side of the second switching valve is formed, a second bypass passage is formed, and a third switching is made to a gas passage on the downstream side of the branch point of the second bypass passage. A valve is interposed, and the second A fourth switching valve is provided in the bypass passage, and particles and / or mist contained in the source gas are removed in the gas passage between the first switching valve and the branch point of the second bypass passage. And removing the second switching means for stabilizing the flow rate of the source gas and purging the gas passage between the first switching valve and the branch point of the second bypass passage. When both the valve and the third switching valve are closed and the first switching valve and the fourth switching valve are both opened, and the source gas is allowed to flow into the processing container for film formation, process instrumentation, characterized by being configured the said first switching valve third switching valve so as to both provide a valve control unit to open state while the both closed the fourth switching valve and the second switching valve It is.

According to by that invention in claims 1 and 2, since the provided first and second plurality of bypass passages with respect to the gas passage, even if the raw material gas adhering to the inner wall of the gas passage is eliminated The desorbed gas can be exhausted from the bypass passage to the vacuum exhaust system without reaching the surface of the wafer (object to be processed), and the raw material gas adhering to the inner wall of the gas passage is altered to form a film. Even if it peels off and becomes particles, the particles can be exhausted from the bypass passage to the vacuum exhaust system without reaching the wafer surface, so that the source gas can be stably supplied. It is possible to prevent the film quality from deteriorating.

According to a third aspect of the present invention, there is provided a raw material gas supply system configured to supply a raw material gas into a processing container through a gas passage, a processing container having a mounting table on which an object to be processed is mounted, and the processing In a processing apparatus having an evacuation system for evacuating the inside of the container, a first bypass passage for bypassing the processing container is communicated between the gas passage and the evacuation system, and the source gas In order to switch the flow of gas, a first switching valve is interposed in the gas passage, and a second switching valve is interposed in the first bypass passage, and a gas passage on the downstream side of the first switching valve And a second bypass passage is formed so as to communicate with the evacuation system, and a third switching valve is provided in a gas passage downstream of the branch point of the second bypass passage, 4th switching valve in the bypass passage And a removal means for removing particles and / or mist contained in the raw material gas is provided in the gas passage between the first switching valve and the branch point of the second bypass passage. In order to stabilize the flow rate of the source gas, both the first switching valve and the third switching valve are closed, the second switching valve is opened, and the first switching valve and the second switching valve are opened. When purging the gas passage between the branch passages of the bypass passage, the second switching valve and the third switching valve are both closed and the first switching valve and the fourth switching valve are both closed. When the source gas is allowed to flow into the processing vessel for film formation in the open state, both the second switching valve and the fourth switching valve are closed, and the first switching valve and the third switching are set. Joint valve A processing apparatus characterized by being configured to provide a valve control unit that open.

According to a fourth aspect of the present invention, there is provided a raw material gas supply system configured to supply a raw material gas into a processing container through a gas passage, a processing container having a mounting table on which an object to be processed is mounted, and the processing In a processing apparatus having an evacuation system for evacuating the inside of the container, a first bypass passage for bypassing the processing container is communicated between the gas passage and the evacuation system, and the source gas In order to switch the flow of gas, a first switching valve is interposed in the gas passage, and a second switching valve is interposed in the first bypass passage, and a gas passage on the downstream side of the first switching valve And a second bypass passage is formed so as to communicate with the evacuation system, and a third switching valve is provided in a gas passage downstream of the branch point of the second bypass passage, 4th switching valve in the bypass passage And a removal means for removing particles and / or mist contained in the raw material gas is provided in the gas passage between the first switching valve and the branch point of the second bypass passage. When stabilizing the flow rate of the source gas and purging the gas passage between the first switching valve and the branch point of the second bypass passage, both the second switching valve and the third switching valve are used. When the first switching valve and the fourth switching valve are both opened and the source gas is allowed to flow to the processing vessel for film formation, the second switching valve and the fourth switching valve are closed. The processing apparatus is characterized in that a valve control unit is provided for both closing the valves and opening both the first switching valve and the third switching valve.
For example, according to claim 5, a vaporizer is installed in the gas passage near the branch point of the first bypass passage, and the branch point of the second bypass passage is set close to the processing vessel. ing.

  According to this, instead of immediately introducing the raw material gas that has started to flow into the gas passage to the processing vessel side, the raw material gas that has flowed through the gas passage after the gas passage has been conditioned by the raw material gas for a certain period of time. Is introduced into the processing container, the controllability of the flow rate of the raw material gas is improved, the film characteristics can be improved, and the reproducibility of the processing can be further improved. Here, the meaning of the expression of “familiarize” means that the phenomenon such as adhesion / desorption / decomposition of the source gas to the inner wall of the gas passage is in a substantially equilibrium state.

Further, for example , according to claim 6, the gas passage is provided with a purge gas introduction pipe for introducing an inert gas into the gas passage.
For example , according to the seventh aspect, the connection position of the purge gas introduction pipe to the gas passage is upstream of the removing means.
Further, for example, as prescribed in請Motomeko 8, wherein the portion where the raw material gas flows, preventing heating means for heating to prevent re-liquefaction and / or re-solidification of the raw material gas is provided.
For example , as defined in claim 9, the raw material is a raw material for forming a PZT thin film.

According to a related art of the present invention, in the processing method using the processing apparatus according to claim 1 or 2, when the flow rate of the raw material gas is stabilized, both the first and third switching valves are closed. At the same time, when the second switching valve is opened and the gas passage between the first switching valve and the branch point of the second bypass passage is purged, both the second and third switching valves are closed. When the film forming process is performed, both the second and fourth switching valves are closed, and the first and third switching valves are closed. The processing method is characterized in that both valves are opened.

The related art of the present invention is the processing method performed using the processing apparatus according to claim 1 or 2, wherein the flow rate of the source gas is stabilized, and the branch point between the first switching valve and the second bypass passage When purging the gas passage between the first and fourth switching valves, both the second and third switching valves are closed, and when the first and fourth switching valves are both opened and the film forming process is performed. The processing method is characterized in that both the second and fourth switching valves are closed, and both the first and third switching valves are opened.

According to a related art of the present invention, in the processing method performed using the processing apparatus according to claim 1 or 2, when the gas passage has a vaporizer for vaporizing the liquid raw material and the vaporizer is maintained, the first method is performed. Both the first and third switching valves are closed and the second switching valve is opened to stabilize the flow rate of the raw material gas, and the branch point between the first switching valve and the second bypass passage. When purging the gas passage between the first and fourth switching valves, both the second and third switching valves are closed, and when the first and fourth switching valves are both opened and the film forming process is performed, The processing method is characterized in that both the second and fourth switching valves are closed, and both the first and third switching valves are opened.
Further, for example, as defined in claim 10, wherein the removal means is a filter means.

Further, for example, as defined in claim 11, wherein the trapping means is a trap means utilizing the difference in inertial force of the particles and / or mist to gas.
Further, for example, as defined in claim 12 , the trap means includes an attachment plate that causes the gas flow of the source gas to collide and adhere to the particles and / or mist.
Further, for example , as defined in claim 13, a throttle part for accelerating the flow rate of the source gas is provided at the gas introduction port through which the source gas flows into the attachment plate.
Further, for example, as defined in claim 14 , the adhesion plate is provided with a scattering prevention member for preventing the particles and / or mist adhered to the adhesion plate from scattering.

By the processing equipment of the present invention lever it can exert effects excellent as follows.

According to the engaging Ru invention claims 1 to 9. Thus providing the first and second plurality of bypass passages with respect to the gas passage, even if the raw material gas adhering to the inner wall of the gas passage is eliminated The desorbed gas can be exhausted from the bypass passage to the vacuum exhaust system without reaching the surface of the wafer (object to be processed), and the raw material gas adhering to the inner wall of the gas passage is altered to form a film. Even if it peels off and becomes particles, the particles can be exhausted from the bypass passage to the vacuum exhaust system without reaching the wafer surface, so that the source gas can be stably supplied. It is possible to prevent the film quality from deteriorating.

According to the related art of the present invention, the raw material gas that has started to flow into the gas passage is not immediately introduced into the processing vessel, but also includes the gas passage (removing means (filter means) when the removing means is provided). ) For a certain period of time with the source gas, then the source gas flowing through this gas passage is introduced into the processing vessel, so that the controllability of the source gas flow rate is improved and the film characteristics are improved. Not only can this be improved, but the reproducibility of the process can be further improved.

According to the invention which concerns on Claims 10-14 , the trap means is provided in the gas passage downstream from the branch point of the first bypass passage of the gas passage for flowing the raw material gas, and / or the particles contained in the raw material gas and / or Since the mist is removed, it is possible to prevent particles and / or mist from flowing into the processing container, and therefore, it is possible to send a high-quality raw material gas and prevent deterioration of the film quality. be able to. Further, since the source gas does not flow through the trap means when the source gas flows through the first bypass passage, the maintenance frequency can be reduced.
Further, in the case where the first and second bypass passages are provided for the gas passage, in addition to the above-described effects, this removal is performed even when the source gas adhering to the inner wall of the gas passage is desorbed. The released gas can be exhausted from the bypass passage to the vacuum exhaust system without reaching the surface of the wafer (object to be processed), and the raw material gas adhering to the inner wall of the gas passage changes in quality to form a film. Even if the particles are peeled off, the particles can be exhausted from the bypass passage to the vacuum exhaust system without reaching the wafer surface. Therefore, the raw material gas can be stably supplied and the film quality is deteriorated. Can be prevented.

Hereinafter, an example of processing equipment according to the present invention will be described in detail with reference to the accompanying drawings.
<First embodiment>
FIG. 1 is a schematic configuration diagram showing a first embodiment of a processing apparatus according to the present invention. Here, as an example, a PZT thin film is deposited as a thin film of a composite metal oxide using an organometallic liquid raw material containing Pb as a liquid raw material, an organometallic liquid raw material containing Zr, and an organometallic liquid raw material containing Ti. explain.

The names of raw materials used are as follows. Since both are solid raw materials at room temperature and normal pressure, they are dissolved in a solvent.
<Organic metal liquid raw material containing Pb>
Bisdipivaloylmethanato lead:
[Pb (C ₁₁ H ₁₉ O ₂ ) ₂ ]
<Organic metal liquid raw material containing Zr (1)>
Zirconium isopropoxy trisdipivaloylmethanato:
_{[Zr (O-i-C} 3 H 7) (C 11 H 19 O 2) 3]
<Organic metal liquid raw material containing Zr (2)>
Zirconium diisopropoxybisdipivaloylmethanato:
_{[Zr (O-i-C} 3 H 7) 2 (C 11 H 19 O 2) 2]
<Organic metal liquid raw material containing Zr (3)>
Zirconium tetrakisdipivaloylmethanato:
[Zr (C ₁₁ H ₁₉ O ₂ ) ₄ ]
<Organic metal liquid raw material containing Ti>
Titanium diisopropoxybisdipivaloylmethanato:
_{[Ti (O-i-C} 3 H 7) 2 (C 11 H 19 O 2) 2]
Moreover, as a solvent for dissolving these solid raw materials, butyl acetate, octane, tetrahydrofuran (THF), hexane, or the like can be used.
A solid sublimation method in which a raw material gas is obtained by directly sublimating a solid raw material such as PZT may be used.

  As shown in FIG. 1, the processing apparatus 2 includes a processing container 4 formed into a cylindrical shape with, for example, aluminum, and a semiconductor wafer W as an object to be processed is placed in the processing container 4. A mounting table 6 to be placed is accommodated. A resistance heater 8 is embedded in the mounting table 6 as a heating unit in order to heat the wafer W. A shower head portion 10 for introducing a processing gas into the inside is provided at the ceiling portion of the processing container 4, and an exhaust port 12 for exhausting the processed gas is provided at the bottom portion. Connected to the exhaust port 12 is a vacuum exhaust system 20 in which a pressure adjusting valve 14 for adjusting the pressure inside the container, a trap 16 for removing by-products from the treated exhaust gas, a vacuum pump 18 and the like are sequentially provided. The inside of the processing container 4 is evacuated by the evacuation system 20. The vacuum exhaust system 20 is provided with open / close valves 22 and 24 for opening and closing the vacuum exhaust system 20, for example, upstream and downstream of the pressure adjustment valve 14.

  In addition, a raw material gas supply system 26 for introducing a raw material gas into the processing container 4 is connected to the shower head portion 10 of the processing container 4. Specifically, the raw material gas supply system 26 has a gas passage 28 made of a pipe connected to the shower head unit 10, and a liquid used here is provided at the tip of the gas passage 28. A vaporizer 30 for vaporizing the raw material is provided, and the raw material gas generated here is caused to flow along the gas passage 28. Further, in the middle of the gas passage 28 and downstream of the branch point P0 of the first bypass passage 36, a filter means 32 is interposed here as a removing means characterized by the present invention. Mist components (mist components), particles, and the like contained in the raw material gas flowing through the gas passage 28 can be removed.

Examples of the filter means 32 include a metal gas filter (a product of Nippon Pole Co., Ltd. or a product of Japan Millipore Co., Ltd.). A first switching valve 34 for switching between opening and closing is interposed in the gas passage 28 on the upstream side of the filter means 32.
Further, a first bypass passage 36 made of piping is connected so as to communicate between the gas passage 28 on the upstream side of the first switching valve 34 and the downstream side of the pressure adjustment valve 14 of the evacuation system 20. The raw material gas is diverted to the processing container 4 as necessary. In FIG. 1, the connection destination of the first bypass passage 36 is immediately downstream of the pressure adjustment valve 14, but it may be connected between the opening / closing valve 24 and the trap 16 or to the trap 16 itself.

The first bypass passage 36 is provided with a second switching valve 38 for switching between opening and closing. The first switching valve 34 and the second switching valve 38 are controlled by a valve control unit 40 made of, for example, a microcomputer.
The vaporizer 30, the gas passage 28, the first switching valve 34 and the filter means 32 provided in the gas passage 28, the first bypass passage 36, and the first bypass passage 36 are provided in the first bypass passage 36. In the upstream portion of the 2 switching valve 38 and the trap 16 of the vacuum exhaust system 20, a prevention heating means 42 (illustrated example) for heating the raw material gas to prevent re-liquefaction or re-solidification. Is shown by a broken line). This prevention heating means 42 consists of tape heaters etc., for example, and is provided by winding this tape heater.

On the other hand, a liquid passage 44 and a carrier gas passage 46 made of piping are connected to the vaporizer 30. The tip of the liquid passage 44 is positioned in the liquid material M1 stored in the first liquid storage tank 48. As the liquid raw material M1, for example, the above-mentioned mixed liquid of PbZrTi liquid raw material is used.
In the middle of the liquid passage 44, a liquid flow rate controller 50 such as a liquid mass flow controller for controlling the flow rate of the liquid raw material flowing therethrough, and an open / close valve positioned on the upstream side and the downstream side of the flow rate controller 50. 52 are interposed. In addition, the first liquid storage tank 48 is provided with an inert gas nozzle 54 for introducing a pressurized inert gas, for example, pressurized He, into the space in the tank to pump the liquid raw material M1. Yes.
The carrier gas passage 46 is provided with a flow controller 56 such as a mass flow controller and an opening / closing valve 58 in the middle of the carrier gas passage 46 to supply a pressurized inert gas such as He gas for vaporization. The liquid material can be vaporized by the vessel 30. Instead of the above He gases, other inert gases such as Ar gas, Ne gas, N ₂ gas, etc. may be used.

Next, the operation of the first embodiment configured as described above will be described.
First, when an unprocessed semiconductor wafer W is mounted on the mounting table 6 in the processing container 4 and a film forming process is started, first, the second switching valve 38 of the first bypass passage 36 is first opened to be here. The source gas is allowed to flow, and the first switching valve 34 of the gas passage 28 is closed so that the source gas does not flow here.
In this state, when the liquid raw material M1 in the first liquid storage tank 48 is pumped by pressurized He and flows into the vaporizer 30 while controlling the flow rate of the liquid raw material M1, the liquid raw material M1 enters the vaporizer 30. Then, it is evaporated by the pressurized He gas introduced through the carrier gas passage 46 and becomes a raw material gas and flows into the gas passage 28. Since the first switching valve 34 is closed and the second switching valve 38 is opened, this source gas flows through the first bypass passage 36 and is evacuated. It flows into the vacuum exhaust system 20 and is exhausted as it is.

As described above, the reason for exhausting the initial raw material gas when the liquid raw material M1 starts flowing is that the flow rate of the liquid raw material M1 itself is unstable because the operations of the liquid flow rate controller 50 and the vaporizer 30 are unstable at the beginning. This is because it becomes unstable and high-precision flow rate control cannot be performed.
In this manner, when the raw material gas is exhausted for a certain time, for example, about 2 to 3 minutes, and the flow rate of the liquid flow rate M1 becomes stable, the second switching valve 38 is then switched to the closed state. In addition to closing the first bypass passage 36 and switching the first switching valve 34 to the open state, the raw material gas flows along the gas passage 28 and the raw material gas passes through the filter means 32. After that, the film is supplied into the processing container 4 and the film forming process is actually started. Then, the film forming process is performed by continuously flowing the source gas for a predetermined time.

At this time, even if the source gas formed in the vaporizer 30 contains a mist component, the mist component is adsorbed and removed by the filter means 32 provided in the gas passage 28, and the mist component is processed into the processing container. Since the film 4 does not adhere to the surface of the wafer W in the film 4, the film quality is not deteriorated, and a thin film having good electrical characteristics can be formed. Of course, the filter means 32 can also remove normal particles.
Further, during the series of operations described above, the preventive heating means 42 is energized, and this is heated to, for example, about 200 ° C. to prevent the source gas flowing in each part from being reliquefied or resolidified.

Thus, since the filter means 32 is provided in the gas passage 28, particles and mist components in the source gas can be surely removed, and as a result, a thin film of metal oxide having good film characteristics. Can be obtained.
Further, for example, when a certain number of wafers are processed, the filter means 32 is clogged. Therefore, the operation of the processing apparatus 2 is stopped regularly or irregularly, and the filter means 32 is maintained, so that particles and mist Replace the clogged filter due to the above.

Here, since the gas was actually flowed with the apparatus configuration shown in FIG. 1 and the particles were evaluated, the evaluation results will be described. In the apparatus configuration shown in FIG. 1, after measuring the PZT film, a particle measuring wafer W (size: 6 inches) is transferred into the processing container 4 and the carrier gas is controlled at 350 sccm from a flow rate controller 56 comprising a mass flow controller. While flowing through the vaporizer 30, the first switching valve 34, the gas passage 28, and the shower head unit 10, the gas flowed into the processing container 4 for 5 minutes. Particles (size: 0.16 μm or more) that have reached particle measurement wafer W (size: 6 inches) when filter means 32 is installed at position A1 of gas passage 28 and when filter means 32 is not installed When the number of the target) was measured, the following results were obtained, and the effect of installing the filter means 32 was confirmed.
With filter means 32 → 102 Without filter means 32 → 15012 In addition, the number of particles of another wafer transferred to the processing container after the PZT film formation is measured, not the number of particles of the wafer on which the PZT film formation has been performed. The reason is that the surface of the wafer on which the PZT film is formed is not flat because the PZT crystal grows, and it is difficult to distinguish and measure the uneven PZT crystal and particles.

  In the above embodiment, the filter means 32 is provided at the point A1 which is a position immediately downstream of the first switching valve 34. However, the filter means 32 is not limited to this installation position, and the filter means 32 is, for example, the first switching valve 34. May be provided at a point A2 which is a position between the first bypass passage 36 and the branch point P0 of the first bypass passage 36. In this case as well, particles and mist components can be removed from the raw material gas as described above. Can exhibit various effects. Here, the mist and particles will be described. The mist is a liquid raw material which is not completely vaporized inside the vaporizer when the liquid raw material is vaporized and is discharged from the vaporizer in a mist state and its solidified product. Particles are solidification of vaporized (sublimated) raw materials and their denatured products that have aggregated and solidified inside the vaporizer, piping, valves, etc., and solidification of raw materials attached to the inner walls of vaporizers, piping, valves, etc. This is a general term for things that have been peeled off.

<Second embodiment>
Next, a second embodiment of the present invention will be described.
In general, when this type of film forming process is performed for a long period of time, it is inevitable that the component of the raw material gas adheres to the filter means 32, and as described above, the filter means 32 is periodically or irregularly. Will be replaced after maintenance. The maintenance work of the filter means 32 is performed by stopping the operation of the entire apparatus and lowering the temperature of the gas passage 28 and the first bypass passage 36 to room temperature. Since the film forming process cannot be resumed unless the passage 28, the first bypass passage 36, etc. are raised to a predetermined temperature, the apparatus must be stopped for a long time. Therefore, from the viewpoint of improving the throughput and the apparatus operating rate, it is preferable to extend the life of the filter means as much as possible to reduce the number of maintenance operations for this replacement as much as possible.

In such a situation, when the filter means 32 is installed at the point A3 in FIG. 1, it is possible to remove the vaporizer 30 from the vaporizer 30 regardless of whether it is during film formation or during non-film formation (stabilization of the flow rate of the source gas). All the raw material gas passes through the filter means 32 and maintenance work of the vaporizer 30 (vaporizer nozzle cleaning, vaporizer internal cleaning, vaporizer inert gas purge, vaporizer temperature change, vaporizer vacuuming Etc.), more mist particles are generated than in the normal film formation, but all these mist particles reach the filter means 32 and the filter means 32 is easily clogged. Since the passage resistance to the gas passing through the filter means 32 is relatively high, the filter means 32 must be replaced frequently, and the throughput and apparatus It would be forced to significant reduction in 働率.
Further, when the filter means 32 is installed at the point A1 in FIG. 1, the raw material gas does not pass through the filter means 32 when the flow rate of the raw material gas is stabilized, and the raw material gas is supplied to the filter means 32 only during film formation. Since gas passes through, the replacement frequency of the filter means 32 can be reduced as compared with the case where it is installed at the point A3.

However, in this case, since a very small amount of source gas generated from the mist of the liquid source collected and accumulated in the filter means 32 reaches the semiconductor wafer W immediately before the film formation, the film is deposited. There is a possibility that film characteristics such as the film thickness of the composite metal oxide thin film (PZT thin film) deposited on the surface of the wafer may not be stabilized.
Further, when the filter means is installed at the point A2 in FIG. 1, the source gas passes through the filter means 32 only during the film formation as in the case where the filter means is installed at the point A1, however, the non-development is not performed. Since the filter means 32 is not completely separated from the raw material gas flowing on the first bypass passage 36 side in the membrane, the replacement frequency of the filter means 32 is set at the point A1 and at the point A3. The frequency is about the middle of the case. Further, when the filter unit 32 is installed at the point A2, a very small amount of source gas generated from the filter unit 32 during the non-film formation is put into the pipe between the filter unit 32 and the first switching valve 34. Since the accumulated source gas flows, when the first switching valve 34 is opened to form a film, it flows downstream and flows into the processing container 4. In this case as well, film characteristics such as film thickness can be obtained. There is a risk of decline.

Therefore, the second embodiment of the present invention solves the above problems.
FIG. 2 is a schematic configuration diagram showing a second embodiment of the processing apparatus according to the present invention, and FIG. 3 is an explanatory diagram for explaining an open / close operation state of each switching valve in the second embodiment. Note that the same components as those shown in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
As shown in FIG. 2, in the case of the second embodiment, the filter means 32 is provided at a point A <b> 1 in FIG. 1, that is, a point B <b> 3 immediately downstream of the first switching valve 34. A second bypass passage 60 made of piping is provided so as to connect the gas passage 28 immediately downstream of the filter means 32 and the first bypass passage 36 downstream of the second switching valve 38. . A third switching valve 62 is interposed in the gas passage 28 downstream from the branch point P1 of the second bypass passage 60 from the gas passage 28, and the second bypass passage 60 includes A fourth switching valve 64 is interposed. The switching operation of each switching valve 34, 38, 62, 64 is controlled by the valve control unit 40 as described above. Here, the distance from the first switching valve 34 to the branch point P1 of the second bypass passage 60 is 1 m or more. Further, the distance from the third switching valve 62 to the processing container 4 is 0.5 m or less.

In the second embodiment configured as described above, the switching valves 34, 38, 62, and 64 are controlled as shown in FIG. In FIG. 3, ◯ indicates that the valve is open, ● indicates that the valve is closed, and Δ indicates that the valve may be open or closed.
First, when the film forming operation is started, first, in order to stabilize the flow rate of the source gas as shown in Step 1, both the first switching valve 34 and the third switching valve 62 are closed and the filter means 32 and most of The source gas is not allowed to flow through the gas passage 28, while the second switching valve 38 is opened. Note that the fourth switching valve 64 may be in an open or closed state. Thereby, the raw material gas generated in the vaporizer 30 flows through the first bypass passage 36 until the flow rate is stabilized, and is exhausted through the vacuum exhaust system 20. This is the same as in the case of the first embodiment shown in FIG. In this case, the raw material gas does not flow through the filter means 32, and even if a very small amount of raw material gas is generated from the mist in the filter means 32, the third switching valve 62 is closed, so that the raw material gas is not treated by the processing vessel. 4 does not flow into. The operation of step 1 for stabilizing the flow rate of the source gas is performed, for example, for about 2 to 3 minutes.

  Next, when the flow rate of the source gas is stabilized, both the first switching valve 34 and the fourth switching valve 64 are used to purge (exclude) the gas component in the filter means 32 as shown in Step 2. The open state is set, and both the second switching valve 38 and the third switching valve 62 are closed. As a result, the raw material gas generated in the vaporizer 30 sequentially flows through the first switching valve 34, the filter means 32, and the second bypass passage 60 (fourth switching valve 64) and is exhausted to the vacuum exhaust system 20. become. As a result, a very small amount of source gas generated in the filter means 32 during the period of step 1 or the like is exhausted to the vacuum exhaust system 20 side via the second bypass passage 60 without being supplied into the processing container 4. Will be. At the same time, the filter means 32 is also well adapted to the raw material gas, and the gas flow rate in this portion is also stabilized. Here, the familiar state means that phenomena such as attachment / desorption / decomposition of the raw material gas to the filter means 32 are in a substantially equilibrium state. At this time, the third switching valve 62 is closed, so that the raw material generated in the filter means 32 does not flow into the processing container 4. The operation of step 2 for removing the trace gas is performed for about 1 to 2 minutes, for example.

Next, when the removal of the trace gas is completed, as shown in step 3, both the second switching valve 38 and the fourth switching valve 64 are closed, and the first switching valve 34 and the third switching valve 62 are turned on. Keep both open. Thereby, the raw material gas generated in the vaporizer 30 flows through the gas passage 28, that is, sequentially flows through the first switching valve 34, the filter means 32, and the third switching valve 62 and flows into the processing container 4, and the wafer The film formation is actually started on the surface of W.
As described above, in the case of the second embodiment, when the gas flow rate is stabilized in Step 1, the raw material gas is not passed through the filter means 32, the actual gas purge in Step 2 and the actual Step 3 are performed. Since the source gas is allowed to flow through the filter means 32 only when the film is formed, not only can the frequency of maintenance work such as the replacement work of the filter means 32 be greatly suppressed, but also the filter means when not forming the film. Since a very small amount of source gas generated from 32 is exhausted without being introduced into the processing vessel 4, the controllability of the flow rate of the source gas is improved and the film characteristics of the thin film deposited on the wafer W are also improved. In addition, the reproducibility of processing can be improved. Such a technique is particularly effective for processes in which film quality control at the interface with the wafer greatly affects the overall film characteristics, such as a PTO nucleation process.

Here, since the PZT film was actually formed using the second embodiment shown in FIG. 2 and the first embodiment shown in FIG. 1, the evaluation results of the composition ratio reproducibility at that time will be described.
Here, in the case where 12 PZT films are continuously formed in the apparatus configuration of the first embodiment, and in the case where 50 PZT films are continuously formed in the apparatus configuration of the second embodiment, A of each wafer is formed. The / B composition ratio was compared. The A / B composition ratio is a numerical value obtained by dividing the number of moles of Pb contained in a PZT film per unit area by the sum of the number of moles of Zr and the number of moles of Ti. Defined.
A / B = Pb / (Zr + Ti)
It is known that the electrical characteristics of the PZT film greatly depend on this A / B composition ratio. As a result of the experiment, an A / B composition ratio as shown in FIG. 4 was obtained. FIG. 4 is a characteristic diagram showing the A / B composition ratio reproducibility of the first and second examples. FIG. 4 (A) shows data on the A / B composition ratio, and FIG. It is the figure which plotted the data shown to A).
In the first embodiment, the film forming recipe is set so that the A / B composition ratio is 1.02, and in the second embodiment, the A / B composition ratio is 1.04. As a result of the experiment, the reproducibility of the A / B composition ratio in the first example was ± 2.55% when only 12 films were formed, but the reproducibility of the A / B composition ratio in the second example was 50. It was found that the number of sheets formed was improved to ± 0.77%. The value of reproducibility (±%) is given by the following equation.
(Maximum value-minimum value) / (2 x average value)

  In the second embodiment, the filter means 32 is provided at the point B3. However, the filter means 32 is not limited to this position. For example, the filter means 32 may be provided at the point B1 downstream from the third switching valve 62, or It may be provided at a point B2 that is between the third switching valve 62, and further may be provided at a point B4 that is between the branch point P0 and the first switching valve 34. In the first and second embodiments, the raw material gas is formed by vaporizing the liquid raw material with a vaporizer. However, as described above, the present invention is also applicable to the raw material gas supply method using the solid sublimation method. Is possible. Although the downstream side of the second bypass passage 60 is connected to the first bypass passage 36 here, it may be connected directly to the vacuum exhaust system 20 side. These points are similarly applied to embodiments described later.

  Further, in place of the valve opening / closing operation shown in FIG. 3, when the flow rate of the raw material gas is stabilized, and when the gas passage between the first switching valve 34 and the branch point of the second bypass passage 60 is purged In the case where both the second and third switching valves 38 and 62 are closed and the first and fourth switching valves 34 and 64 are both opened, the second and third switching valves 38 and 62 are opened. The fourth switching valves 38 and 64 may be both closed, and the first and third switching valves 34 and 62 may be both opened.

<Third embodiment>
In the second embodiment, the filter means 32 is provided. However, even when the raw material gas supply system 26 is a solid sublimation method or a solution vaporization method (a method of vaporizing a liquid raw material with a vaporizer), the raw material can be vaporized. In the case where the mist is generated successfully, the filter means may not be provided as in the third embodiment shown in FIG. 5, and the piping configuration of the first and second bypass passages 36 and 60 may be adopted.
In this case, since the first and second plural bypass passages are provided for the gas passage, even if the source gas adhering to the inner wall of the gas passage is desorbed, the desorbed gas is removed from the wafer. It can be exhausted from the bypass passage to the vacuum exhaust system without reaching the surface, and even if the source gas attached to the inner wall of the gas passage changes in quality and becomes a film, it peels off and becomes particles, The particles can be exhausted from the bypass passage to the vacuum exhaust system without reaching the wafer surface. Therefore, the raw material gas can be stably supplied, so that the film quality can be prevented from being deteriorated.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described.
In the first and second embodiments described above, as the liquid source M1 stored in the first liquid storage tank 48, an organometallic liquid source containing Pb, an organometallic liquid source containing Zr, and an organic containing Ti A material in which three kinds of metal liquid raw materials are mixed in advance was used. However, when a PZT metal oxide thin film is formed, PTO metal oxide nucleation may be performed on the wafer surface as a pre-process. .
In order to perform this PTO metal oxide nucleation step, an organometallic liquid raw material containing Pb and an organometallic liquid raw material containing Ti are used.

FIG. 6 is a schematic configuration diagram showing a fourth embodiment of the processing apparatus according to the present invention for performing the two steps as described above, and FIG. 7 is a diagram for explaining the operating state of each switching valve in the fourth embodiment. It is explanatory drawing of. The same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is omitted.
As shown in FIG. 6, in the fourth embodiment, a liquid material supply system used when nucleating PTO metal oxide is added to the second embodiment shown in FIG. It is. That is, a mixture of an organometallic liquid source containing Pb and an organometallic liquid source containing Ti is used as the liquid source M2, and a second liquid storage tank 70 for storing the liquid source M2 made of this mixed liquid is provided. Then, the lower end is immersed in the liquid raw material M2 in the liquid storage tank 70, and the tip is connected to the inlet side of the vaporizer 30 of the liquid passage 44 through which the other liquid raw material M1 flows. Set up.

In the middle of the liquid passage 72, the liquid flow rate controller 74 such as a liquid mass flow controller for controlling the flow rate of the liquid raw material flowing through the liquid passage 72, and the upstream side and the downstream side of the flow rate controller 74 are positioned. An open / close valve 76 is interposed. The second liquid storage tank 70 is provided with an inert gas nozzle 78 for introducing an inert gas pressurized to pump the liquid source M2 into the space in the tank, for example, pressurized He. Yes. Thereby, both liquid raw materials M1 and M2 can be selectively supplied to the vaporizer 30. Instead of the above He gases, other inert gases such as Ar gas, Ne gas, N ₂ gas, etc. may be used.

In the fourth embodiment, an inert gas such as He gas, Ar gas, Ne gas, N ₂ gas or the like is supplied into the gas passage 28 immediately upstream of the filter means 32 to supply the gas passage 28. A purge gas introduction pipe 80 is provided to prevent contamination inside. The purge gas introduction pipe 80 can also be installed in the first embodiment, the second embodiment, and the third embodiment in order to prevent contamination in the gas passage 28.
In the case of this fourth embodiment, the switching valves 34, 38, 62, 64 are controlled as shown in FIG. 7, and as described above, the first PTO metal oxide nucleation process in steps 1-3. Then, the liquid source M2 containing Pb and Ti is used as the liquid source, and the liquid source M1 containing Pb, Ti and Zr is used as the liquid source in the PZT metal oxide film forming process of Steps 4-6. In this case, the valve operation of each switching valve 34, 38, 62, 64 in steps 1-3 is exactly the same as the valve operation of each switching valve 34, 38, 62, 64 in steps 4-6. Incidentally, the valve operations in steps 1 to 3 and 4 to 6 shown in FIG. 7 are naturally the same as the valve operations in steps 1 to 3 shown in FIG.

Further, during the non-film-formation purge in which no raw material gas is allowed to flow from the vaporizer 30, the first switching valve 34 is closed and the second switching valve 38 is opened, and the He carrier gas from the carrier gas passage 46 is opened. As a purge gas, the He gas flows from the vaporizer 30 through the gas passage 28 partway and then through the first bypass passage 36.
Further, when it is desired to simultaneously purge the filter means 32 during non-film formation in which no source gas is allowed to flow from the vaporizer 30, the third switching valve 62 is closed and the fourth switching valve 64 is opened. As a result of the evacuation by flowing an inert gas such as He as a purge gas from the purge gas introduction pipe 80, the He gas flows from the purge gas introduction pipe 80 through the filter means 32 and the gas passage 28, and then the second bypass passage 60 Flows through. Therefore, the raw material gas adhering to the filter means 32 and the inner wall of the gas passage 28 will be discharged accompanying the He gas at this time.

  As described above, even when PTO metal oxide nucleation is performed as a pretreatment and a PZT metal oxide thin film is subsequently deposited, the source gas does not flow into the filter means 32 when the gas flow rate is stabilized. In addition, since the raw material gas generated from the mist of the liquid raw material captured in the filter unit 32 can be prevented from being inadvertently introduced into the processing container 4, the replacement frequency of the filter unit 32 can be reduced, In addition, the film characteristics of the thin film deposited on the wafer surface can be improved. In some cases, the valve operation may be intentionally performed as shown in FIG. The valve operation as shown in FIG. 8A can be applied when the gas flow rate stabilization time is relatively short. Further, the valve operation as shown in FIG. 8B includes an operation of cleaning the vaporizer with a solvent in Steps 1 and 8, and can be applied to the case where the vaporizer is cleaned with a solvent every film formation. Further, the valve operation as shown in FIG. 8C includes an operation for cleaning the vaporizer in steps 1 and 10, and an operation for cleaning the gas piping and filter means in steps 2 and 9. This can be applied to the case where the vaporizer, the gas pipe, and the filter means are washed with a solvent for each film.

<Fifth embodiment>
Next, a fifth embodiment will be described.
The filter means 32 used in the first to fourth embodiments described above generally includes a mesh-like or linear air-permeable filter member (not shown) densely laid inside. However, these filter members tend to clog relatively easily when particles or mist are captured, and the maintenance frequency tends to increase. Therefore, instead of the filter means 32 in the first to fourth embodiments, a trap means having substantially the same function as the filter means 32 and requiring a relatively low maintenance frequency may be provided. .

FIG. 9 is a block diagram showing a fifth embodiment of such a processing apparatus of the present invention. Here, as a representative, a trap means 90 is provided in place of the filter means 32 in the first embodiment shown in FIG. The case is described. Note that the same components as those shown in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
FIG. 10 is an enlarged configuration diagram of the trap means, and FIG. 11 is a plan view showing an attachment plate of the trap means and this support structure. As shown in FIGS. 9 and 11, here, the trap means 90 is provided in the gas passage 28 on the downstream side of the first switching valve 34 to remove these by utilizing the difference in inertial force of particles and mist with respect to the gas. It is set up. The trap means 90 has a cylindrical trap container 92 having an inner diameter larger than that of the gas passage 28. The trap container 92 has a length that can be disassembled for maintenance. In the middle of the direction, it can be divided into two parts.

  Specifically, a flange 94 is provided in the divided portion, and the flange 94 is fastened and fixed in an airtight manner by a bolt 98 via a seal member 96 such as an O-ring. A gas introduction pipe 100 for introducing a raw material gas is provided at the distal end side of the trap container 92, and a flange 102 provided at the distal end portion of the gas introduction pipe 100 is an O-ring or the like at the downstream end of the upstream gas passage 28. The seal member 104 is attached and fixed in an airtight manner by a bolt 106. The gas introduction port 100A, which is the downstream end of the gas introduction pipe 100, is formed with a constricted portion 108 having a narrow passage area so that the inner diameter thereof is smaller than the inner diameter of the gas passage 28. The flow rate of the source gas introduced into the trap container 92 is increased. The inner diameter of the gas introduction port 100A may be set to be the same as the inner diameter of the gas passage 28 without providing the throttle portion 108.

  A gas discharge pipe 110 is provided at the rear end side of the trap container 92, and a flange 112 provided at the rear end portion of the gas discharge pipe 110 is sealed with an O-ring or the like at the upstream end of the downstream gas passage 28. The bolts 116 are hermetically attached and fixed via the members 114. In the trap container 92, there is provided an attachment plate 118 for attaching and removing mist and particles in the source gas by colliding them. Specifically, the adhering plate 118 has a central portion that is an axis in the trap container 92 by a plurality of support legs 120 (see FIG. 11A) extending from the inner wall of the trap container 92 in the illustrated example. Supported by the department. Here, the attachment plate 118 is formed in a substantially circular shape, and a screw rod 122 extends downstream from the back surface thereof. The screw hole 122 is supported by the three support legs 120 in common. The attachment plate 118 is supported by being screwed into the screw hole 126 of the member 124, and the distance between the attachment plate 118 and the gas inlet 100 </ b> A by rotating the screw rod 122 forward and backward. L2 can be adjusted. The trap container 92 is heated by the prevention heating means 42 in the same manner as the above-described filter means, and the structure in the trap container 92, that is, the attachment plate 118, the support leg 120, the screw rod 122, and the screw hole member 124. Etc. are simultaneously heated by the heat transfer of the member itself.

  Further, a scattering preventing member 126 for preventing scattering of particles and mist adhering to the adhesion plate 118 is provided around the circular adhesion plate 118. Specifically, here, the scattering prevention member 126 is formed as a circular cylinder 128, and the base end portion of the cylinder 128 is fixed along the outer periphery of the adhesion plate 118. Therefore, the adhering plate 118 and the cylinder 128 are formed into a container shape as a whole. Further, a tapered surface 128A is formed along the circumferential direction at the distal end portion of the cylindrical body 128, and mist and particles are prevented from adhering to the distal end portion. Here, the inner diameter of the gas passage 28 is, for example, 1/2 inch (12.7 mm), the inner diameter D1 of the throttle portion 108 is, for example, 3/8 inch (9.5 mm), and the outer diameter D2 of the cylindrical body 128 (attachment plate 118). Is the same as the inner diameter D1 of the throttle 108, for example, 3/8 inch (9.5 mm), the distance L2 between the gas inlet 100A and the attachment plate 118 is, for example, 30 mm, and the inner diameter of the trap container 92 is, for example, 30 to It is about 40 mm.

Next, the operation of the trap means 90 will be described.
In FIG. 10, a linear arrow indicates a gas flow, and a satin arrow indicates a flow of particles or the like. This also applies to the illustrated examples described later.
First, the source gas flowing in the upstream gas passage 28 increases in gas velocity when passing through the throttle portion 108 of the gas inlet 100A of the trap means 90, so that the trap container 92 is in a state where its inertial force is increased. It is introduced in. Since the adhesion plate 118 is installed at a position facing the gas inlet 100A, the mist and particles whose inertial force is larger than that of the gas (gas) go straight to the adhesion plate 118. It collides and adheres here and is removed from the gas. At this time, the gas (gas) having a small inertial force flows around the scattering prevention member 126 including the adhesion plate 118 and the cylindrical body 128 by detouring easily in the outer circumferential direction, and the gas passage on the downstream side of the gas discharge pipe 110. It will flow towards 28.

In this way, mist and particles in the source gas can be adhered to the adhesion plate 118, and these can be removed from the gas almost certainly. In this case, the adhering matter M3 adheres and accumulates on the adhering plate 118. Since the adhering plate 118 is surrounded by the scattering prevention member 126 made of the cylindrical body 128, the adhering matter M3 is downstream by the gas flow. It is possible to prevent scattering to the side.
Further, since the inner diameter D1 of the gas inlet 100A and the diameter D2 of the attachment plate 118 are set to be substantially the same, the mist and particles introduced into the trap container 92 surely collide with the attachment plate 118. Therefore, the capture rate of particles and mist can be improved. Further, as described above, unlike the filter means 32 described above, since clogging that causes a reduction in the capture rate does not occur, the maintenance frequency can be greatly reduced. Needless to say, the effects obtained by providing the filter means 32 in the first to fourth embodiments are also obtained in this embodiment.

  Further, in order to increase the collision efficiency between the particles or mist and the adhesion plate 118, it is preferable to set the diameter D2 of the adhesion plate 118 small so as not to be smaller than the inner diameter D1 of the gas inlet 100A. Furthermore, the larger the parameter Ns (= L2 / D1) represented by the ratio of the distance L2 and the inner diameter D1, the better the capture rate of particles and the like. However, it is preferable to set this parameter Ns to 2 or more. In the present embodiment, this parameter Ns (= 30 mm / 9.5 mm) is set to 3.16. However, if the inner diameter D1 is excessively decreased in order to increase the parameter Ns, the flow rate of the gas blown out from the gas inlet 100A becomes too fast, and there is a possibility that the mist and particles once captured will re-scatter. Since it occurs, it is not preferable. Further, if the distance L2 is set too long, the straightness of the mist and particles blown out from the gas inlet 100A is lost, and there is a possibility that the mist and particles may flow away from the adhesion plate 118 and flow downstream.

  In the case shown in FIG. 10, the case where the scattering prevention member 126 made of the cylindrical body 128 is attached to the disc-like adhering plate 118 has been described as an example. However, the present invention is not limited to this, and the configuration shown in FIG. May be. FIG. 12 is a view showing a modified example of the adhesion plate. In the case shown in FIG. 12A, only the disc-like adhesion plate 118 is provided, and no scattering prevention member is provided. In the case shown in FIG. 12B, a scattering prevention member 126 made of, for example, a net member 130 is provided on the surface of the disc-shaped adhesion plate 118 to prevent the captured matter from being scattered again. In this case, the net member 130 may be provided as a single layer as illustrated, or may be provided as a multilayer. In the case shown in FIG. 12C, a scattering prevention member 126 made of a cylindrical body 134 is provided on the outer periphery of the disc-shaped adhesion plate 118 through a vent hole 132. In this case, the flow of gas flow can be made smooth by suppressing the increase in exhaust conductance by the amount of the vent holes 132 provided.

The trap means 90 of the fifth embodiment has been described by taking the case where the adhesion plate 118 is disposed in the trap container 92 as an example, but the present invention is not limited to this, and a part of the wall surface of the trap container 92 is used as the adhesion plate 118. You may do it. FIG. 13 is a schematic configuration diagram showing a modified example of such trap means 90. In FIG. 13, the overall structure is simplified.
In the case shown in FIG. 13A, the trap container 92 is formed in a substantially cylindrical shape, and the gas introduction tube 100 is inserted through the one end plate 92A to the back. An end plate 92 </ b> B opposite to the cylindrical trap container 92 is configured as an attachment plate 118. In addition, a gas discharge pipe 110 is connected to the side wall of the trap container 92 near the end plate 92A so that the gas is discharged toward the downstream side.

In the case shown in FIG. 13 (A), the gas introduced into the trap container 92 from the gas introduction pipe 100 directly hits the end plate 92B almost vertically, where mist and particles having a large inertial force are applied to the end plate 92B. It adheres to the plate 92B and is removed. Then, the gas (gas) having a small inertial force is bounced off by the end plate 92B, the traveling direction is reversed (changes 180 degrees), and flows downstream from the gas discharge pipe 110. In this case, the deposit M3 is deposited on the adhesion plate 118 of one end plate 92B of the cylindrical trap container 92.
In the case shown in FIG. 13 (B), the trap container 92 is bent in an approximately L shape, and the wall surface 92C of the bent portion is formed into a flat plate inclined at approximately 45 degrees, and this is configured as the adhesion plate 118. . The gas introduction pipe is arranged such that the extending direction of the gas introduction pipe 100 inserted through the one end plate 92A of the trap container 92 is inclined at approximately 45 degrees with respect to the adhesion plate 118. 100 is set. In addition, a gas discharge pipe 110 is connected to the side wall of the trap container 92 near the end plate 92A so that the gas is discharged toward the downstream side.

  In the case shown in FIG. 13B, the gas introduced into the trap container 92 from the gas introduction pipe 100 hits the adhesion plate 118 made of the inclined wall surface 92C, where most of the mist having a large inertial force and The particles adhere to the wall surface 92C and are removed as the deposit M3. At this time, a part of the mist and particles bounced in the oblique direction upon hitting the inclined wall surface 92C are deposited on the bottom plate 92D of the trap container 92 as the deposit M3. On the other hand, the gas (gas) having a small inertial force is bounced back by the inclined wall surface 92C and the bottom plate 92D and flows downstream from the gas discharge pipe 110.

  In the case shown in FIG. 13C, the trap container 92 is formed in a substantially cylindrical shape and is provided upright, and the bottom plate 92F of the trap container 92 is configured as the adhesion plate 118. The gas introduction pipe 100 and the gas discharge pipe 110 are connected to the ceiling plate 92E of the trap container 92. In the case shown in FIG. 13C, the gas introduced into the trap container 92 from the gas introduction pipe 100 directly hits the bottom plate 92D, where mist and particles having a large inertia force adhere to the bottom plate 92D. And removed as a deposit M3. The gas (gas) having a small inertial force is bounced back by the bottom plate 92D, the traveling direction is reversed (changes 180 degrees), and flows downstream from the gas discharge pipe 110.

  In each of the embodiments described above, liquid raw materials M1 and M2 containing two kinds of metal elements (raw liquid containing Pb and Ti) or three kinds (raw liquid containing Pb, Ti and Zr) as liquid raw materials. In the above description, M3 is used as an example, but liquid raw materials independently containing each metal element are used separately, and these are first mixed and vaporized in the vaporizer 30 or a pipe portion (manifold) in front thereof. Good.

In each of the above embodiments, the process of forming a PZT metal oxide film is described as an example of the film forming process. However, any process that uses a source gas obtained by vaporizing a liquid source or sublimating a solid source can be used. The present invention can also be applied to such a process. For example, a thin film of SBT metal oxide using an organometallic raw material containing Sr, an organometallic raw material containing Bi, and an organometallic raw material containing Ta can be used. When forming a thin film of a BLT metal oxide using an organometallic raw material containing Bi, an organometallic raw material containing La, and an organometallic raw material containing Ti, or an organometallic raw material containing Sr The present invention can also be applied to the case where an STO metal oxide thin film or the like is formed using an organometallic raw material containing Ti.
Further, the structure inside the processing container 4 is merely an example, and a heating lamp may be used as the heating means. Furthermore, the object to be processed is not limited to a semiconductor wafer, and the present invention can be applied to a glass substrate, an LCD substrate, and the like.

<Related art of the present invention>
Next, related technology of the present invention will be described.
FIG. 14 is a schematic configuration diagram showing an example of a processing apparatus for explaining the related art of the present invention. The configuration shown in FIG. 14 is exactly the same except that the difference in the configuration shown below is changed from FIG.
In general, when a source gas flows in a pipe, gas components tend to adhere to the inner wall of the pipe. Therefore, if the piping is long, the raw material gas adhering to the inner wall of the piping may adversely affect the processing. For example, despite the fact that the switching valve is closed, the raw material gas generated from the inner wall of the piping located downstream of the switching valve tends to flow into the processing vessel, and the raw material gas flow becomes worse. The controllability of the process is inferior and the reproducibility of the process may be reduced. Further, the raw material gas adhering to the inner wall of the pipe is re-evaporated at the time of film formation, and a gas flow rate higher than a predetermined flow rate is introduced into the processing container.

Therefore, in the configuration shown in FIG. 14, the piping distance L <b> 1 between the point P <b> 3 that is the outlet of the first switching valve 34 provided in the gas passage 28 and the point P <b> 4 that is the inlet of the shower head unit 10 of the processing container 4. Is set as small as possible, for example, about 30 cm. Further, a point P2 where the first bypass passage 36 branches from the gas passage 28 is formed as close to the first switching valve 34 as possible. Further, the second switching valve 38 interposed in the first bypass passage 36 is provided as close to the point P2 as possible.
By forming as described above, when the first switching valve 34 is closed at the end of the film formation or the like, the pipe distance L1 between the point P3 and the point P4 is short, so that it adheres to the pipe inner wall of this part. Since the source gas is very small, the source gas is easily cut off. Therefore, the controllability of the flow rate of the source gas is improved, and the process reproducibility can be improved.

Even when the inside of the processing container 4 is opened to the atmosphere for maintenance inside the processing container 4, the first switching valve 34 is closed to adhere to the inner wall surface of the pipe having the pipe distance L1. Moisture and oxygen components in the atmosphere are also very small, and the reproducibility of processing can be improved more than this point.
When no material gas is allowed to flow from the vaporizer 30, the first switching valve 34 is closed, the second switching valve 38 is opened, and a He carrier gas is allowed to flow as a purge gas from the carrier gas passage 46 to perform evacuation. As a result, the He gas flows from the vaporizer 30 through the gas passage 28 to the point P2, and then flows through the first bypass passage 36.

Therefore, the raw material gas adhering to the inner wall of the gas passage 28 extending from the point Y1 to the point P2 which is the outlet of the vaporizer 30 is exhausted by the He gas at this time.
Therefore, when the film forming process is performed next, since the source gas hardly adheres to the inner wall of the gas passage 28 extending from the point Y1 to the point P2, the controllability of the source gas flow rate is improved. The reproducibility of processing can be improved from the point.

It is a schematic block diagram which shows 1st Example of the processing apparatus which concerns on this invention. It is a schematic block diagram which shows 2nd Example of the processing apparatus which concerns on this invention. It is explanatory drawing for demonstrating the operation state of opening and closing of each switching valve in 2nd Example. It is a characteristic view which shows the A / B composition ratio reproducibility of 1st and 2nd Example. It is a schematic block diagram which shows 3rd Example of the processing apparatus which concerns on this invention. It is a schematic block diagram which shows 4th Example of the processing apparatus which concerns on this invention. It is explanatory drawing for demonstrating the operation state of opening and closing of each switching valve in 4th Example. It is a figure which shows the modification of valve operation. It is a block diagram which shows 5th Example of the processing apparatus of this invention. It is an enlarged block diagram which shows a trap means. It is a top view which shows the adhesion board and support structure of a trap means. It is a figure which shows the modification of an adhesion plate. It is a schematic block diagram which shows the modification of a trap means. It is a schematic block diagram which shows an example of the processing apparatus for demonstrating the related technology of this invention.

Explanation of symbols

2 Processing device 4 Processing container 6 Mounting table 8 Resistance heater (heating means)
20 Vacuum exhaust system 26 Raw material gas supply system 28 Gas passage 30 Vaporizer 32 Filter means (removal means)
34 1st switching valve 36 1st bypass passage 38 2nd switching valve 40 Valve control part 42 Prevention heating means 60 2nd bypass passage 62 3rd switching valve 64 4th switching valve 90 Trap means (removal means)
W Semiconductor wafer (object to be processed)

Claims (14)

A raw material gas supply system configured to supply the raw material gas into the processing container through the gas passage;
A processing container having a mounting table on which a target object is mounted;
An evacuation system for evacuating the inside of the processing vessel;
In a processing apparatus having
A first bypass passage for bypassing the processing vessel is communicated between the gas passage and the vacuum exhaust system, and a first switching valve is interposed in the gas passage for switching the flow of the source gas. And a second switching valve is interposed in the first bypass passage,
A second bypass passage is formed so as to connect the gas passage on the downstream side of the first switching valve and the first bypass passage on the downstream side of the second switching valve, and a branch point of the second bypass passage A third switching valve is provided in the downstream gas passage, a fourth switching valve is provided in the second bypass passage, and a branch point between the first switching valve and the second bypass passage is provided. the gas passage between, interposed removal means for removing particles and / or mist contained in the raw material gas,
When stabilizing the flow rate of the source gas, both the first switching valve and the third switching valve are closed and the second switching valve is opened.
When purging the gas passage between the first switching valve and the branch point of the second bypass passage, both the second switching valve and the third switching valve are closed and the first switching is performed. Open both the valve and the fourth switching valve,
When the source gas is allowed to flow into the processing container for film formation, both the second switching valve and the fourth switching valve are closed, and both the first switching valve and the third switching valve are opened. A processing apparatus, characterized in that a valve control unit for bringing into a state is provided . A raw material gas supply system configured to supply the raw material gas into the processing container through the gas passage;
A processing container having a mounting table on which a target object is mounted;
An evacuation system for evacuating the inside of the processing vessel;
In a processing apparatus having
A first bypass passage for bypassing the processing vessel is communicated between the gas passage and the vacuum exhaust system, and a first switching valve is interposed in the gas passage for switching the flow of the source gas. And a second switching valve is interposed in the first bypass passage,
A second bypass passage is formed so as to connect the gas passage on the downstream side of the first switching valve and the first bypass passage on the downstream side of the second switching valve, and a branch point of the second bypass passage A third switching valve is provided in the downstream gas passage, a fourth switching valve is provided in the second bypass passage, and a branch point between the first switching valve and the second bypass passage is provided. the gas passage between, interposed removal means for removing particles and / or mist contained in the raw material gas,
When the flow rate of the raw material gas is stabilized and the gas passage between the first switching valve and the branch point of the second bypass passage is purged, both the second switching valve and the third switching valve are closed. Both the first switching valve and the fourth switching valve are opened,
When the source gas is allowed to flow into the processing container for film formation, both the second switching valve and the fourth switching valve are closed, and both the first switching valve and the third switching valve are opened. A processing apparatus, characterized in that a valve control unit for bringing into a state is provided . A raw material gas supply system configured to supply the raw material gas into the processing container through the gas passage;
A processing container having a mounting table on which a target object is mounted;
An evacuation system for evacuating the inside of the processing vessel;
In a processing apparatus having
A first bypass passage for bypassing the processing vessel is communicated between the gas passage and the vacuum exhaust system, and a first switching valve is interposed in the gas passage for switching the flow of the source gas. And a second switching valve is interposed in the first bypass passage,
A second bypass passage is formed so as to connect the gas passage on the downstream side of the first switching valve and the evacuation system, and a third gas passage is formed downstream of the branch point of the second bypass passage. A switching valve is provided, a fourth switching valve is provided in the second bypass passage, and the source gas is provided in a gas passage between the first switching valve and the branch point of the second bypass passage. A removal means for removing particles and / or mist contained therein,
When stabilizing the flow rate of the source gas, both the first switching valve and the third switching valve are closed and the second switching valve is opened.
When purging the gas passage between the first switching valve and the branch point of the second bypass passage, both the second switching valve and the third switching valve are closed and the first switching is performed. Open both the valve and the fourth switching valve,
When the source gas is allowed to flow into the processing container for film formation, both the second switching valve and the fourth switching valve are closed, and both the first switching valve and the third switching valve are opened. A processing apparatus, characterized in that a valve control unit for bringing into a state is provided . A raw material gas supply system configured to supply the raw material gas into the processing container through the gas passage;
A processing container having a mounting table on which a target object is mounted;
An evacuation system for evacuating the inside of the processing vessel;
In a processing apparatus having
A first bypass passage for bypassing the processing vessel is communicated between the gas passage and the vacuum exhaust system, and a first switching valve is interposed in the gas passage for switching the flow of the source gas. And a second switching valve is interposed in the first bypass passage,
A second bypass passage is formed so as to connect the gas passage on the downstream side of the first switching valve and the evacuation system, and a third gas passage is formed downstream of the branch point of the second bypass passage. A switching valve is provided, a fourth switching valve is provided in the second bypass passage, and the source gas is provided in a gas passage between the first switching valve and the branch point of the second bypass passage. A removal means for removing particles and / or mist contained therein,
When the flow rate of the raw material gas is stabilized and the gas passage between the first switching valve and the branch point of the second bypass passage is purged, both the second switching valve and the third switching valve are closed. Both the first switching valve and the fourth switching valve are opened,
When the source gas is allowed to flow into the processing container for film formation, both the second switching valve and the fourth switching valve are closed, and both the first switching valve and the third switching valve are opened. A processing apparatus, characterized in that a valve control unit for bringing into a state is provided .   The vapor passage is installed in the gas passage near the branch point of the first bypass passage, and the branch point of the second bypass passage is set close to the processing container. The processing apparatus as described in any one of 1-4.   The processing apparatus according to any one of claims 1 to 5, wherein a purge gas introduction pipe for introducing an inert gas into the gas passage is provided in the gas passage.   The processing apparatus according to claim 6, wherein a connection position of the purge gas introduction pipe to the gas passage is upstream of the removing unit.   8. The preventive heating means for heating to prevent re-liquefaction and / or re-solidification of the raw material gas is provided in a portion where the raw material gas flows. Processing equipment.   The processing apparatus according to claim 1, wherein the raw material is a raw material for forming a PZT thin film.   The processing apparatus according to claim 1, wherein the removing unit is a filter unit.   The processing apparatus according to claim 1, wherein the removing unit is a trap unit that uses a difference in inertial force of the particles and / or mist with respect to gas. The processing apparatus according to claim 11 , wherein the trap means has an attachment plate that causes the gas flow of the source gas to collide with the particles and / or mist. The processing apparatus according to claim 12 , wherein a throttle part for accelerating a flow rate of the source gas is provided at a gas introduction port through which the source gas flows toward the attachment plate. The processing apparatus according to claim 12 or 13 , wherein the adhesion plate is provided with a scattering prevention member for preventing scattering of the particles and / or mist adhered to the adhesion plate.

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