JP2008066413A - Shower head structure and treatment device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shower head structure capable of drastically raising through-put by considerably suppressing an unnecessary attachment film to be deposited on a gas spraying surface, so as to reduce a frequency of maintenance such as cleaning treatment, etc. <P>SOLUTION: The shower head structure 68 sprays a plurality of prescribed kinds of gas to a treatment space S in a treatment container 34 in order to perform a prescribed treatment with respect to an object W to be treated. This structure includes: a container shape shower head main body 70 having a plurality of internal gas supply chambers 84, 86 and divided with gas spray boards 80, whose surface facing the treatment space is composed of an air-permeable and porous member; and gas spray tubes 72 arranged by extending from the gas supply chambers, which do not contact the gas spray boards in the plurality of gas supply chambers, and penetrating the gas spray boards. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a processing apparatus for performing a predetermined process such as a film forming process on an object to be processed such as a semiconductor wafer and a shower head structure used therefor.

In general, in order to manufacture a semiconductor device, a substrate such as a semiconductor wafer as an object to be processed is repeatedly subjected to various processes such as a film forming process, an etching process, a modification process, and an oxidative diffusion process. It is supposed to manufacture devices.
Here, a film forming apparatus that performs a film forming process among the above various processes will be described as an example (Patent Documents 1 to 3). FIG. 8 is a schematic configuration diagram showing an example of a conventional film forming apparatus, and FIG. 9 is an enlarged sectional view showing a part of the shower head structure in FIG.

  As shown in FIG. 8, this processing apparatus has a processing container 2 formed in a cylindrical shape, and the inside of the processing container 2 is an exhaust system 8 provided with a vacuum pump 4, a pressure control valve 6 and the like. Can be evacuated. In the processing container 2, a mounting table 12 in which a heating means 10 made of, for example, a resistance heater is embedded is provided. On the mounting table 12, for example, a semiconductor wafer W is mounted as an object to be processed. This can be heated to a desired temperature. Further, the mounting table 12 is provided with a lifter pin mechanism 14 that can be moved up and down to push the wafer W onto the mounting table 12 when the semiconductor wafer W is carried into and out of the processing container 2.

  A shower head structure 16 for introducing a predetermined gas for film formation into the processing container 2 is provided on the ceiling of the processing container 2. Here, the shower head structure 16 is provided with gas diffusion chambers 18 and 20 which are divided into two upper and lower two stages inside. The gas injection plate 22 on the lower surface of the shower head structure 16 includes a plurality of gas injection holes 18A communicating with one of the two gas diffusion chambers 18 and 20, and the other gas injection chamber. A plurality of gas injection holes 20A communicated with the gas injection holes 20A are provided so as to be substantially evenly dispersed, and the gases respectively supplied from the gas injection holes 18A and 20A are mixed in the processing space S for the first time. It has become. Here, the two gas diffusion chambers 18 and 20 are provided. However, depending on the type of film to be formed, there may be one gas diffusion chamber or three or more gas diffusion chambers.

  Further, in order to uniformly supply gas and prevent the generation of particles, the entire gas injection plate 22 is also formed of a porous material such as ceramic (Patent Documents 4 and 5).

  When a film forming process is performed using such a film forming apparatus, not only the target wafer surface but also the surface of the mounting table 12, the inner wall surface of the processing container 2, the surface of the shower head structure 16, and the like are unnecessary. It is inevitable that an adhesion film is deposited. Since this unnecessary adhesion film causes generation of particles when it is peeled off, a cleaning process for removing the deposited unnecessary adhesion film is periodically or irregularly performed to prevent the generation of particles. It has been broken.

In this cleaning process, generally, a cleaning gas made of a halogen gas such as ClF ₃ or NF ₃ is used, and this is flowed into the film forming apparatus to remove unnecessary films. Performed in-situ without decomposition.

JP 2005-19479 A Japanese Patent Laid-Open No. 11-323560 JP 2002-9062 A JP 2003-45809 A JP 2004-228426 A

By the way, when performing the cleaning process as described above, as a matter of course, the process for the product wafer must be stopped. Therefore, in order to improve the throughput of the wafer process, as much as possible unnecessary adhesion is required. It is desirable not to deposit a film.
In particular, a gas injection hole 18A or a gas injection hole as shown in FIG. 9 is provided on the gas injection surface 22A, which is the lower surface of the gas injection plate 22 of the shower head structure 16 that is disposed opposite to the mounting table 12 and introduces the source gas. A part of the raw material gas injected from 20A turns inward as shown by an arrow 24 to form a vortex, and this entrained raw material gas comes into contact with the gas injection surface 22A and is unnecessary here. It was a cause of depositing a large amount of adhering film. There is a tendency that a lot of unnecessary films tend to be deposited on the gas ejection surface 22A for the above-described reason as compared with other portions such as the surface of the mounting table 12. From the viewpoint of improving the throughput, It was important to reduce the amount of deposition.

  Therefore, as shown in Patent Documents 4 to 6, it has been proposed that the entire gas injection plate 22 is made of a porous ceramic material. In this case, it is effective when the same gas is injected from the entire gas injection plate 22, but as shown in FIGS. 8 and 9, a plurality of gas diffusion chambers 18 and 20 are provided to process a plurality of gases. When the gases must be supplied in a so-called post-mixed state in which both gases are mixed for the first time when injected into the space S, this cannot be handled.

In particular, when a ferroelectric film made of an oxide film containing Pb, Zr and Ti (hereinafter also referred to as “PZT film”) is formed, a PZT source gas is supplied from one gas injection hole, for example, 20A. A film is formed by supplying an inert gas such as Ar gas or an oxidizing gas such as O ₂ from the other gas injection hole 18A. The PZT film reacts with a halogen-based gas such as ClF ₃ or NF _3. Since the vapor pressure of the resulting metal halide is low and does not become a gas at room temperature, it is difficult to discharge the metal halide from the processing vessel. Therefore, the PZT film cannot be removed with the halogen-based gas. Therefore, in order to remove the unnecessary PZT film, the film forming apparatus itself is disassembled, for example, the shower head structure itself to which a large amount of unnecessary PZT film is adhered is washed with a strong cleaning solution or blasted. As a result, there is a problem that the cleaning process is performed, the apparatus itself must be stopped for a long time, and the throughput is significantly reduced.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a shower head structure capable of significantly suppressing unnecessary adhesion films deposited on a gas ejection surface and reducing the frequency of maintenance such as cleaning processing, thereby significantly improving throughput. It is to provide a processing apparatus.

  According to a first aspect of the present invention, there is provided a shower head structure that injects a plurality of types of predetermined gases into a processing space in a processing container in order to perform a predetermined processing on an object to be processed. A container-like shower head body having a surface facing the processing space defined by a gas injection plate made of a breathable porous member, and a gas that does not contact the gas injection plate in the plurality of gas diffusion chambers A shower head structure comprising: a gas injection pipe extending from the diffusion chamber and provided through the gas injection plate.

In this way, the surface facing the processing space is formed by the gas injection plate made of a porous member having air permeability, and the gas in one gas diffusion chamber is supplied from the entire gas injection plate having air permeability, while the other Since the gas in the gas diffusion chamber is supplied from the gas injection pipe provided through the gas injection plate, the gas supplied from the gas injection plate purges the gas supplied from the other gas injection pipe. Since the gas is prevented from flowing around and coming into contact with the gas injection surface, it is possible to prevent an unnecessary adhesion film from being deposited on the gas injection surface.
Therefore, unnecessary adhesion films deposited on the gas ejection surface can be significantly suppressed, and the maintenance frequency such as the cleaning process can be reduced, thereby greatly improving the throughput.

In this case, for example, as described in claim 2, the gas injection pipe is provided with a tip protruding from the surface of the gas injection plate by a predetermined length.
According to a third aspect of the present invention, there is provided a shower head structure that injects a plurality of types of predetermined gases into a processing space in a processing container in order to perform a predetermined processing on an object to be processed. A container-shaped shower head body having a surface facing the processing space defined as a gas spray plate, and a plurality of gas spray plates provided on the gas spray plate so as to communicate independently with the plurality of gas diffusion chambers. And a breathable porous member loaded in a gas injection hole communicated with a specific gas diffusion chamber among the plurality of gas injection holes. It is.

In this way, the gas in one gas diffusion chamber is supplied from one gas injection hole provided in the gas injection plate, and the gas in the other gas diffusion chamber is supplied to the other gas in which a porous member having air permeability is loaded. Since the gas is supplied from the injection hole, the gas supplied from the gas injection hole loaded with the porous member purges the gas supplied from the other gas injection hole, and this gas wraps around the gas injection surface. Therefore, it is possible to prevent an unnecessary adhesion film from being deposited on the gas ejection surface.
Therefore, unnecessary adhesion films deposited on the gas ejection surface can be significantly suppressed, and the maintenance frequency such as the cleaning process can be reduced, thereby greatly improving the throughput.

In this case, for example, as described in claim 4, the porous member is provided with a tip protruding from the surface of the gas injection plate by a predetermined length.
Further, for example, as described in claim 5, the gas injection hole in which the porous member is not loaded is formed by a gas injection pipe, and the tip of the gas injection pipe has a predetermined end than the surface of the gas injection plate. It is provided to project by the length of.
For example, as described in claim 6, the porous member is made of one or more materials selected from a ceramic porous material, a metal porous material, and a ceramic-metal composite porous material.

Further, for example, as described in claim 7, the plurality of gas diffusion chambers are provided in the shower head main body by being divided into a plurality of layers and formed in layers.
For example, as described in claim 8, the predetermined process is a film forming process, and the gas passing through the porous member is selected from the group consisting of an inert gas, an oxidizing gas, a reducing gas, and a nitriding gas. One gas.
According to a ninth aspect of the present invention, there is provided a processing apparatus for performing a predetermined process on an object to be processed, a processing container that can be evacuated, a mounting table that holds the object to be processed in the processing container, A processing apparatus comprising: the shower head structure according to any one of the above, which is provided to face a mounting table.

According to the shower head structure and the processing apparatus using the same according to the present invention, the following excellent operational effects can be exhibited.
According to the present invention, the surface facing the processing space is formed by the gas injection plate made of a porous member having air permeability, and the gas in one gas diffusion chamber is supplied from the entire gas injection plate having air permeability, Since the gas in the other gas diffusion chamber is supplied from the gas injection pipe provided through the gas injection plate, the gas supplied from the gas injection plate is the gas supplied from the other gas injection pipe. The gas is prevented from flowing around and coming into contact with the gas injection surface, so that an unnecessary adhesion film can be prevented from being deposited on the gas injection surface.
Therefore, unnecessary adhesion films deposited on the gas ejection surface can be significantly suppressed, and the maintenance frequency such as the cleaning process can be reduced, thereby greatly improving the throughput.

In particular, according to the inventions according to claims 3 to 5, the gas in one gas diffusion chamber is supplied from one gas injection hole provided in the gas injection plate, and the gas in the specific other gas diffusion chamber is breathable. Since the gas is supplied from the other gas injection hole loaded with the porous member, the gas supplied from the gas injection hole loaded in the porous member purges the gas supplied from the other gas injection hole, Since this gas is prevented from flowing around and coming into contact with the gas injection surface, it is possible to prevent an unnecessary adhesion film from being deposited on the gas injection surface.
Therefore, unnecessary adhesion films deposited on the gas ejection surface can be significantly suppressed, and the maintenance frequency such as the cleaning process can be reduced, thereby greatly improving the throughput.

Hereinafter, an embodiment of a shower head structure and a processing apparatus using the same according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an example of a processing apparatus according to the present invention, FIG. 2 is an enlarged sectional view showing a first embodiment of a shower head structure, and FIG. 3 is a part of a gas injection surface of the shower head structure shown in FIG. FIG. Here, a processing apparatus that performs a film forming process for forming a PZT film by CVD (Chemical Vapor Deposition) will be described as an example of the processing apparatus.

  As shown in the figure, the processing apparatus 32 includes a cylindrical processing container 34 whose side walls and bottom are formed of an aluminum alloy or the like. In the processing container 34, a mounting table 36 for mounting, for example, a semiconductor wafer W as an object to be processed is accommodated on the upper surface thereof. The mounting table 36 is formed in a substantially circular plate shape made of, for example, ceramic such as alumina, and is erected from the bottom of the container via a column 38 made of, for example, aluminum.

  A gate valve 40 that opens and closes when a wafer is loaded into and unloaded from the inside of the processing chamber 34 is provided on the side wall of the processing chamber 34. Further, an exhaust port 42 is provided at the bottom of the container, and an exhaust path 48 to which a pressure control valve 44 and a vacuum pump 46 are sequentially connected is connected to the exhaust port 42, and processing is performed as necessary. The inside of the container 34 can be evacuated to a predetermined pressure.

  A plurality of, for example, three lifting pins 50 (only two are shown in FIG. 1) for raising and lowering the wafer W when the wafer W is loaded and unloaded are provided below the mounting table 36. Is lifted and lowered by a lifting rod 54 provided through the container bottom through an extendable bellows 52. The mounting table 36 is provided with a pin insertion hole 56 through which the elevating pin 50 is inserted. A heating means 58 made of, for example, a thin plate-shaped resistance heater is embedded in the mounting table 36. The heating means 58 is connected to a heater power source 62 via a wiring 60 that passes through the column 38, and heats the wafer W as necessary. Note that a heating lamp provided at the bottom of the container may be used as the heating means 58 instead of the resistance heater. In this case, the mounting table 36 having a reduced thickness is used.

  And the ceiling board 64 of the said processing container 34 is opened, The shower head structure 68 which is the characteristics of this invention is airtightly provided in this opening through sealing members 66, such as an O-ring. The shower head structure 68 is disposed to face the mounting table 36, and supplies a necessary gas to the processing space S formed therebetween.

The shower head structure 68 according to the first embodiment of the present invention includes a shower head main body 70 formed in a thin cylindrical container shape as shown in FIG. 2 and a plurality of gas jets inserted into the shower head main body 70. Mainly constituted by the pipe 72. Specifically, the shower head main body 70 includes a top plate 74 that forms a ceiling portion and a side wall plate 76 that forms a side portion. Necessary gas is supplied to the central portion of the top plate 74 from the outside. A gas introduction port 78 to be introduced is provided.
The gas injection plate 80 that defines the lowermost surface of the shower head body 70, which is the surface facing the processing space S, is entirely formed of a porous member having air permeability. A partition plate 82 made of, for example, an aluminum alloy is provided in the shower head body 70 along the horizontal direction, and a plurality of, here two gas diffusion chambers 84 and 86 are vertically arranged in the upper and lower portions. It is formed in layers in steps.

  The partition plate 82 is connected to the gas injection pipe 72 that communicates with and extends from the upper gas diffusion chamber 84, thereby forming a gas injection hole 72 </ b> A. The gas injection pipe 72 passes through the gas diffusion chamber 86 in the lower stage, and the tip of the gas injection pipe 72 penetrates the gas injection plate 80. The tip of the gas injection pipe 72 is from the gas injection surface 80A which is the surface of the gas injection plate 80. Is projected downward by a predetermined length H1. The length H1 is preferably in the range of several millimeters to several centimeters, for example.

The gas injection pipe 72 is made of, for example, an aluminum alloy, and the inner diameter thereof is set to about several mm to several tens of mm. As shown in FIG. 3, the gas injection pipe 72 is provided so as to be distributed substantially evenly in the plane of the gas injection plate 80. It has been. The distribution density and arrangement pitch of the gas injection tubes 72 are not particularly limited. Further, the thickness H2 (see FIG. 2) of the gas injection plate 80 is, for example, in the range of several mm to several cm, although it depends on the porosity of the porous member constituting the gas injection plate 80.
The gas introduction port 78 is provided with a first gas introduction path 88 that communicates with the upper gas diffusion chamber 84 and a second gas introduction path 90 that communicates with the lower gas diffusion chamber 86. The gas required for each can be introduced while the flow rate is controlled by a flow rate controller (not shown).

  Here, since the PZT film is formed, the PZT source gas is introduced into the first gas introduction path 88, and an inert gas such as Ar can be introduced into the second gas introduction path 90. ing. Here, as the porous member constituting the gas injection plate 80, a ceramic porous material made of alumina, aluminum nitride or the like, a metal porous material made of aluminum or stainless steel, or a ceramic-metal composite made of a composite material of ceramic and metal. A porous material can be used. This also applies to other embodiments described below.

  Returning to FIG. 1, the overall operation of the processing device 32 configured as described above is controlled by a control unit 92 made of, for example, a microcomputer, and a computer program for performing this operation. Is stored in a storage medium 94 such as a floppy, a CD (Compact Disc), a flash memory, or a hard disk. Specifically, supply of each gas, flow rate control, control of process temperature and process pressure, and the like are performed by commands from the control means 92.

Next, a method for forming a PZT film, for example, performed using the processing apparatus 32 configured as described above will be described.
First, the semiconductor wafer W is accommodated in the processing container 34 by the transfer arm (not shown) via the gate valve 40, and the wafer W is placed on the mounting surface on the upper surface of the mounting table 36 by moving the lifting pins 50 up and down. Place. The wafer W is maintained at a predetermined process temperature by the heating means 58 formed of a resistance heater, and the PZT source gas is transferred from the PZT source gas source 140 while controlling the flow rate, and the Ar gas is controlled from the Ar gas source 142 while controlling the flow rate. Each gas is supplied to the processing space S from the shower head structure 68, and the pressure control valve 44 is controlled to maintain the inside of the processing vessel 34 at a predetermined process pressure, and the CVD film forming process of the PZT film is performed.

  Here, in the shower head structure 68, the PZT source gas is introduced into the upper gas diffusion chamber 84 via the first gas introduction path 88 and diffused therein, and the PZT source gas is further introduced into each gas injection pipe 72. And is injected and supplied toward the processing space S. The other Ar gas is introduced into the lower gas diffusion chamber 86 through the second gas introduction path 90 and diffused there, and this Ar gas further has a breathable porous property that defines the gas diffusion chamber 86. As shown by an arrow 100 (see FIG. 2), the gas is injected from the entire gas injection plate 80 made of a porous member toward the lower processing space S and supplied.

  These two gases are mixed for the first time in the processing space S, and a PZT film is formed by thermal CVD. At this time, when the PZT source gas, which is the source gas, is injected from each gas injection pipe 72, the injected PZT source gas circulates like a vortex like the conventional apparatus described in FIG. It tends to contact the gas injection surface 80A side. However, in this embodiment, as described above, Ar gas is injected from the entire gas injection surface 80A made of a porous member as indicated by the arrow 100, so that the PZT raw material gas that is going to go around is injected. Is purged and removed by the Ar gas and flows downward, so that it is possible to prevent the PZT source gas from coming into contact with the gas injection surface 80A with certainty. As a result, the gas injection surface 80A It is possible to prevent deposition of an adhesion film made of an unnecessary PZT film.

Therefore, unnecessary adhesion films deposited on the gas ejection surface 80A can be greatly suppressed to reduce the frequency of maintenance such as cleaning processing, thereby greatly improving the throughput.
In particular, by projecting the tip of the gas injection pipe 72 downward with a predetermined length H1, the PZT source gas is injected at a position away from the gas injection surface 80A. Therefore, it is possible to more reliably prevent the PZT source gas from flowing around and contact the gas injection surface 80A.

As the PZT source gas, a mixed gas of an organometallic compound gas can be used. Specifically, for example, Pb (DPM) ₂ can be used as the Pb source, and Zr source can be, for example, Zr. (T-OC ₄ H ₉ ) ₄ or the like can be used, and Ti (i-OC ₃ H ₇ ) or the like can be used as the Ti raw material.

In addition, an oxidizing gas such as O ₂ , O ₃ , N ₂ O, or NO ₂ may be added as another gas. For example, when supplying an O ₂ or N ₂ O gas, it is premixed with a PZT source gas. When supplying NO ₂ and O ₃ gas in the state (premix), this may be supplied together with Ar gas, or when a third gas diffusion chamber as described later is provided, PZT raw material gas and NO ₂ , O ₃ gas, etc. may be mixed for the first time in the processing space S so as to be supplied through the third gas diffusion chamber (postmix).

<Second embodiment>
Next, a second embodiment of the shower head structure according to the present invention will be described. FIG. 4 is an enlarged sectional view showing a second embodiment of the shower head structure according to the present invention. Note that the same components as those shown in FIG. 2 and the like are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment described above, the gas injection plate 80 is entirely formed of a porous member except for the portion through which the gas injection pipe 72 penetrates. In the second embodiment, the gas injection plate 80 is shown in FIG. As described above, the gas injection plate 80 is formed of a metal plate such as an aluminum alloy as in the conventional apparatus example. A plurality of gas injection holes 110 communicating with the lower gas diffusion chamber 86 are formed at predetermined locations on the gas injection plate 80 made of the metal plate, and a porous ventilation is provided in the gas injection holes 110. A porous member 112 as described above is loaded.

  In this case, the important point is that the tip of the porous member 112 is provided to protrude downward from the gas injection surface (surface) 80A of the gas injection plate 80 by a predetermined length H3. Therefore, Ar gas can be injected not only in the downward direction but also in the horizontal direction (lateral direction). This length H3 is in the range of several millimeters to several centimeters, and this length H3 is set shorter than the protruding length H1 of the gas injection pipe 72 in order to improve the purge action of the PZT source gas. preferable. Note that the lower end portion of the porous member 112 may be formed in a curved shape such as a hemispherical shape instead of an angular cross section.

  According to the second embodiment, Ar gas is not only in the downward direction but also in the horizontal direction (horizontal direction) as shown by the arrow 114 from the protruding portion at the tip of the porous member 112 communicating with the lower gas diffusion chamber 86. In particular, since the PZT source gas that attempts to contact the gas injection surface 80A is purged and removed by the Ar gas injected in the horizontal direction, the PZT source gas is Contact with the gas injection surface 80A can be almost certainly prevented, and as a result, it is possible to prevent the adhesion film made of an unnecessary PZT film from being deposited on the gas injection surface 80A.

  Therefore, unnecessary adhesion films deposited on the gas ejection surface 80A can be greatly suppressed to reduce the frequency of maintenance such as cleaning processing, thereby greatly improving the throughput. Thus, the second embodiment can also exhibit the same operational effects as the first embodiment.

<Third embodiment>
Next, a third embodiment of the shower head structure according to the present invention will be described. FIG. 5 is an enlarged sectional view showing a third embodiment of the shower head structure according to the present invention. The same components as those shown in FIGS. 2 and 4 are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment described above, the gas injection hole 110 is formed in the gas injection plate 80 made of a metal plate, and the porous member 112 is loaded thereon. In the third embodiment, the gas injection hole is used. A gas injection hole 120 </ b> A is formed by providing a gas injection pipe 120 instead of 110. And the front-end | tip of this gas injection pipe 120 is made to protrude below, and it is set as the state which protruded only by predetermined length H4 from 80 A of gas injection surfaces. Here, the porous member is not loaded into the gas injection pipe 120, but instead the porous member 122 is loaded into the other gas injection pipe 72 communicated with the upper gas diffusion chamber 84, and The tip of the injection pipe 72 is set so as to be at the same horizontal level as the gas injection surface 80A without protruding downward from the gas injection surface 80A.

  On the other hand, the porous member 122 loaded in the gas injection pipe 72 has its tip protruded downward from the gas injection surface 80A, and the protrusion amount is set to a predetermined length H5. To do. The porous member 122 may not be provided in the entire gas injection pipe 72 but may be provided only partially on the distal end side. The lengths H4 and H5 are both about several mm to several cm, and it is preferable to set the length H4 to be longer than the length H5 in order to improve the purge action of the PZT source gas. . Note that the lower end portion of the porous member 122 may be formed in a curved shape such as a hemispherical shape instead of an angular cross section.

  Here, the gas diffusion chamber for introducing the PZT source gas and Ar gas is the reverse of the first and second embodiments described above, and Ar gas is introduced into the upper gas diffusion chamber 84, and the lower stage The PZT source gas is introduced into the gas diffusion chamber 86.

  According to the third embodiment, Ar gas is shown from the protruding portion at the tip of the porous member 122 loaded in the gas injection pipe 72 communicating with the upper gas diffusion chamber 84 as indicated by an arrow 124. Since it is supplied so as to be injected not only in the downward direction but also in the horizontal direction (lateral direction), in particular, it is injected from the gas injection pipe 120 that attempts to contact the gas injection surface 80A by Ar gas injected in the horizontal direction. The purged PZT source gas is purged and eliminated, so that the PZT source gas can be prevented from coming into contact with the gas injection surface 80A with certainty. As a result, an unnecessary PZT film is formed on the gas injection surface 80A. It is possible to prevent the deposited film from being deposited.

  Therefore, unnecessary adhesion films deposited on the gas ejection surface 80A can be greatly suppressed to reduce the frequency of maintenance such as cleaning processing, thereby greatly improving the throughput. As described above, this third embodiment can also exhibit the same effects as the first and second embodiments.

<Fourth embodiment>
Next, a fourth embodiment of the shower head structure according to the present invention will be described. FIG. 6 is an enlarged sectional view showing a fourth embodiment of the shower head structure according to the present invention. The same components as those shown in FIG. 1 and the like are denoted by the same reference numerals, and the description thereof is omitted.
In the first to third embodiments described above, the shower head structure provided with two gas diffusion chambers 84 and 86 has been described as an example. However, the present invention is not limited to this, and three or more gas diffusion chambers are layered. Alternatively, a plurality of sections may be formed and provided.

  The fourth embodiment shown in FIG. 6 is based on the shower head structure of the first embodiment shown in FIG. 2, and the shower head main body 70 is provided with three gas diffusion chambers in three layers. Specifically, for example, by providing a lower partition plate 130 below the partition plate 82 that partitions the upper gas diffusion chamber 84, the middle gas diffusion chamber 132 is provided between the partition plates 82 and 130. Thereby, three gas diffusion chambers 84, 132, 86 of the upper stage, the middle stage, and the lower stage are formed.

  The gas introduction port 78 is formed with a third gas introduction pipe 134 which communicates with the middle gas diffusion chamber 132 so that a gas necessary for this can be introduced. The lower partition plate 130 is connected to a plurality of gas injection pipes 136 communicating with the middle gas diffusion chamber 132 and extending downward, and the distal ends of these gas injection pipes 136 are made of the porous member. The gas injection plate 80 is penetrated, and the front end portion of the gas injection plate 80 protrudes further downward than the gas injection surface 80A. The length H6 of the protruding portion of the gas injection pipe 136 is preferably set to the same value as the length H1 of the protruding portion of the gas injection pipe 72 extending from the upper gas diffusion chamber 84.

  In this case, for example, when the first and second source gases that should not be mixed before the gas is jetted into the processing space S, one of the first and second source gases is present. For example, the first source gas is introduced into the upper gas diffusion chamber 84 and the other second source gas is introduced into the middle gas diffusion chamber 132. An inert gas such as Ar gas is introduced into the lower gas diffusion chamber 86. Then, the first source gas, the second source gas, and the Ar gas are mixed for the first time in the processing space S, and a predetermined film forming process is performed.

Also in this case, the same operational effects as those of the first embodiment described above can be exhibited. Even when four or more layers of gas diffusion chambers are provided, it is a matter of course that a gas injection pipe is provided extending downward from each gas diffusion chamber. Further, the number of gas diffusion chambers to be provided is determined depending on the number of source gas groups that cannot be premixed.
In each of the above embodiments, the case where Ar gas is used as the inert gas has been described as an example. However, the present invention is not limited to this, and other inert gases such as He, Ne, Xe, and N ₂ may be used. .

Although the case where a PZT film is mainly formed has been described here as an example, the present invention is not limited to this, and the present invention can be applied to any film forming apparatus using a shower head structure. The present invention can also be applied to a plasma film forming apparatus and a plasma CVD film forming apparatus that generate plasma by high frequency. In this case, the shower head structure 68 serves as the upper electrode and the mounting table 36 serves as the lower electrode. Become.
In the case of forming various film types including the PZT film, the gas injection plate 80 (first, second and fourth embodiments) made of the porous member and the porous members 112 and 122 (second and third embodiments). For example, in addition to the inert gas (Ar) as described above, an oxidative gas such as O ₂ , a reducing gas such as H ₂ , and a nitriding gas such as NH ₃ are allowed to pass through. Can be shed. A source gas (mostly containing a metal component) that may form an adhesion film on the surface of the shower head is allowed to flow so as not to pass through the porous member.

For example, FIG. 7 shows an example of a film type to be formed, a mixing method of each gas, a gas type to be used, and a gas diffusion chamber to be introduced. The premix refers to the case where a plurality of gases are mixed in the same gas diffusion chamber and then ejected into the processing space. The postmix refers to the case where a plurality of gases are ejected from the respective gas diffusion chambers for the first time in the processing space. The case of mixing is shown.
In FIG. 7, Ar gas is used as an example of the inert gas, but other inert gases may be used as described above. When the middle gas diffusion chamber 132 is used, this may be used interchangeably with the gas introduced into the upper gas diffusion chamber 84.

Here, the nitriding gas typified by NH ₃ gas, the oxidizing gas typified by NO ₂ , and the reducing gas typified by H ₂ introduced into the middle gas diffusion chamber 132 are replaced with Ar gas, respectively, or It may be introduced into the lower gas diffusion chamber 86 together with the Ar gas. In this case, of course, the middle gas diffusion chamber 132 is unnecessary. Here, the nitriding gas is also a source gas.

In each of the above embodiments, the film forming process has been described as an example. However, the present invention can be applied to all processing apparatuses in which an adhesion film may be deposited on the surface of the showerhead structure. The present invention can also be applied to an etching processing apparatus in which the generated reaction by-product may be deposited on the surface of the showerhead structure.
Although the semiconductor wafer is described as an example of the object to be processed here, the present invention is not limited thereto, and the present invention can be applied to a glass substrate, an LCD substrate, a ceramic substrate, and the like.

It is a block diagram which shows an example of the processing apparatus which concerns on this invention. It is an expanded sectional view showing the 1st example of a shower head structure. FIG. 3 is a partial plan view showing a part of a gas ejection surface of the shower head structure shown in FIG. 2. It is an expanded sectional view showing the 2nd example of the shower head structure concerning the present invention. It is an expanded sectional view showing the 3rd example of the shower head structure concerning the present invention. It is an expanded sectional view showing the 4th example of the shower head structure concerning the present invention. It is a figure which shows an example of the film | membrane kind to form into a film, the mixing system of each gas, the gas kind to be used, and the gas diffusion chamber to introduce | transduce. It is a schematic block diagram which shows an example of the conventional film-forming apparatus. It is an expanded sectional view which shows a part of shower head structure in FIG.

Explanation of symbols

32 processing apparatus 34 processing container 36 mounting table 58 heating means 68 shower head structure 70 shower head main body 72 gas injection pipe 72A gas injection hole 74 top plate 76 side wall plate 78 gas introduction port 80 gas injection plate 82 partition plate 84 gas diffusion chamber ( (Top)
86 Gas diffusion chamber (lower)
DESCRIPTION OF SYMBOLS 110 Gas injection hole 112 Porous member 120 Gas injection pipe 120A Gas injection hole 122 Porous member 132 Middle stage gas diffusion chamber 136 Gas injection pipe S Processing space W To-be-processed object (semiconductor wafer)

Claims (9)

In a shower head structure for injecting a plurality of types of predetermined gases into a processing space in a processing container in order to perform a predetermined processing on an object to be processed,
A container-like shower head body having a plurality of gas diffusion chambers inside, and a surface facing the processing space defined by a gas injection plate made of a porous member having air permeability;
A gas injection pipe extending from the gas diffusion chamber that does not contact the gas injection plate among the plurality of gas diffusion chambers and provided through the gas injection plate;
A shower head structure characterized by comprising: The shower head structure according to claim 1, wherein the gas injection pipe is provided with a tip projecting a predetermined length from the surface of the gas injection plate. In a shower head structure for injecting a plurality of types of predetermined gases into a processing space in a processing container in order to perform a predetermined processing on an object to be processed,
A container-like shower head body having a plurality of gas diffusion chambers inside, and a surface facing the processing space partitioned as a gas injection plate;
A plurality of gas injection holes provided in the gas injection plate so as to communicate independently with the plurality of gas diffusion chambers;
An air-permeable porous member loaded in a gas injection hole communicated with a specific gas diffusion chamber among the plurality of gas injection holes;
A shower head structure characterized by comprising: The shower head structure according to claim 3, wherein the porous member is provided with a tip projecting from the surface of the gas injection plate by a predetermined length. The gas injection hole in which the porous member is not loaded is formed by a gas injection pipe, and the gas injection pipe is provided with a tip protruding from the surface of the gas injection plate by a predetermined length. The showerhead structure according to claim 3 or 4, wherein the showerhead structure is provided. The showerhead structure according to any one of claims 1 to 5, wherein the porous member is made of one or more materials selected from a ceramic porous material, a metal porous material, and a ceramic-metal composite porous material. The shower head structure according to any one of claims 1 to 6, wherein the plurality of gas diffusion chambers are provided in the shower head body so as to be partitioned into a plurality of layers in a layered manner. The predetermined process is a film forming process, and the gas passing through the porous member is one gas selected from the group consisting of an inert gas, an oxidizing gas, a reducing gas, and a nitriding gas. Item 8. The shower head structure according to any one of Items 1 to 7. In a processing apparatus that performs a predetermined process on an object to be processed,
A processing vessel made evacuable;
A mounting table for holding the object to be processed in the processing container;
The shower head structure according to any one of claims 1 to 8, wherein the shower head structure is provided to face the mounting table.
A processing apparatus comprising:

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