JP2008235632A - Cleaning apparatus and method - Google Patents

Abstract

In a cleaning apparatus and method using a remote plasma processing method, an etching rate is improved, thereby shortening a cleaning time.
A cleaning apparatus for removing deposits from the surface of a constituent member of a film forming apparatus installed in a processing atmosphere of the film forming apparatus, wherein a mounting region on which the constituent member is placed is provided. An active gas supply unit 3 that generates an active gas G by decomposing fluorine-containing reaction gas by plasma and supplies the active gas G into the chamber 2; and water W vaporized in the chamber. And a water supply unit 4 for supplying water.
[Selection] Figure 3

Description

  The present invention relates to a cleaning apparatus and method.

  Conventionally, in a manufacturing process of a liquid crystal device or the like, a film forming apparatus for forming a film made of a predetermined material on a processing target such as a substrate has been used. In such a film forming apparatus, a material source and a processing object are arranged in a chamber, and the film is formed by discharging the material from the material source and attaching it to the processing object.

By the way, in the film forming apparatus, since the material is discharged radially from the material source, the released material adheres to a place other than the processing target. For this reason, a film is also formed at a place other than the processing object. A film formed at a place other than the object to be processed gradually increases in thickness and eventually peels off to become particles.
For this reason, the deposition apparatus prevents the generation of particles by arranging a protective plate that can be removed from the chamber so as to cover the wall of the chamber, and periodically removing the protective plate to perform cleaning. is doing. In addition, the portions that cannot be covered with the adhesion-preventing plate can be removed individually, and can be periodically cleaned. As described above, among the constituent members of the film forming apparatus, the constituent member to which the released material is attached can be removed, and is regularly cleaned.

A so-called blasting method, wet etching method, dry etching method, or the like is used as a method for cleaning the constituent members of the film forming apparatus.
The blasting method is a method in which deposits are peeled off by using glass beads, sand or the like as abrasive grains and polishing the constituent members with the abrasive grains. In addition, the wet etching method is a method in which a deposit is dissolved by a chemical solution and peeled off. In addition, the dry etching method is a method of removing deposits by etching the surface of a constituent member in a gas phase using plasma.

A cleaning apparatus and method using a so-called remote plasma processing method, which is one of dry etching methods, have been conventionally performed.
This remote plasma processing method is a technique in which reactive gas is decomposed by plasma, and an active gas generated thereby is supplied into a chamber in which components are placed, thereby removing deposits by etching.
JP-A-6-49626

  However, the lifetime of the active gas used in the remote plasma processing method is extremely short. For this reason, the area | region which can be exposed to active gas in a chamber is very narrow, and it was difficult for the conventional washing | cleaning apparatus to wash | clean the mounted component uniformly. Since the cleaning of the constituent members is completed after all the deposits are removed, when the cleaning state is uneven, the processing time corresponding to the region with the worst etching rate is required, and thus the processing time becomes long. .

  The present invention has been made in view of the above-described problems, and an object of the present invention is to improve an etching rate in a cleaning apparatus and method using a remote plasma processing method, thereby shortening a cleaning time.

  In order to achieve the above object, a cleaning apparatus of the present invention is a cleaning apparatus for removing deposits from the surface of a constituent member of a film forming apparatus installed in a processing atmosphere of the film forming apparatus. A chamber having a mounting region on which the active gas is mounted; an active gas supply unit that generates an active gas by decomposing a reactive gas containing fluorine by plasma; and supplies the active gas into the chamber; and And a water supply part for supplying vaporized water.

According to the cleaning apparatus of the present invention having such characteristics, the active gas and the vaporized water are supplied into the chamber in which the constituent members are placed. That is, in the cleaning apparatus of the present invention, fluorine radicals (F ^* ) or fluorine ions (F ⁻ ) and water (H ₂ 0) are supplied into the chamber. As a result, the fluorine radical (F ^* ) or fluorine ion (F ⁻ ) reacts with water to produce intermediate products such as hydrogen fluoride (HF) and COF 2, and further hydrogen fluoride (HF) and COF 2. And water react with each other to produce hydrogen fluoride ion (HF ₂ ⁻ ) as a final product.
Fluorine radicals and fluorine ions have a short lifetime, but hydrogen fluoride is stable. For this reason, hydrogen fluoride can fill the entire chamber. Then, hydrogen fluoride further reacts with water to form hydrogen fluoride ions. Since hydrogen fluoride can fill the entire chamber, hydrogen fluoride ions are generated in the entire chamber. Is done. Since the hydrogen fluoride ions are active, the deposits on the constituent members can be etched.
That is, in the cleaning apparatus of the present invention, hydrogen fluoride ions can be present throughout the chamber. For this reason, the whole structural member mounted in the mounting area can be exposed to hydrogen fluoride ions, and an area with a poor etching rate can be eliminated.
Therefore, in the cleaning apparatus using the remote plasma processing method, the etching rate can be improved, thereby shortening the cleaning time.

Moreover, in the washing | cleaning apparatus of this invention, the structure provided with the introduction piping which guides the vaporized water supplied by the said water supply part to the said installation area | region is employ | adopted.
By adopting such a configuration, radical hydrogen fluoride ions can be generated with particular emphasis on the placement region, and the deposits can be etched with a gas having a higher active state. Therefore, the etching rate can be further improved.

Further, in the cleaning apparatus of the present invention, the above-described placement region employs a configuration in which a plurality of the above-described constituent members can be placed.
By adopting such a configuration, a plurality of constituent members can be uniformly and simultaneously cleaned, so that the cleaning time can be further shortened.

Further, in the cleaning apparatus of the present invention, a configuration in which the constituent member is made of stainless steel can be employed.
Moreover, in the cleaning apparatus of the present invention, the above-described constituent member can also be configured to include a base material made of stainless steel and an aluminum layer in which aluminum sprayed on the surface of the base material is solidified.

  Further, the cleaning method of the present invention is a cleaning method for removing deposits from the surface of the constituent members of the film forming apparatus installed in the processing atmosphere of the film forming apparatus, and decomposes the reaction gas containing fluorine by plasma. Thus, an active gas is generated, and the active gas and vaporized water are supplied into a chamber in which the constituent members are placed.

According to the cleaning method of the present invention having such characteristics, the active gas and the vaporized water are supplied into the chamber in which the constituent members are placed. That is, in the cleaning method of the present invention, fluorine radicals (F ^* ) or fluorine ions (F ⁻ ) and water (H ₂ 0) are supplied into the chamber. As a result, fluorine radicals (F ^* ) and fluorine ions (F ⁻ ) react with water to produce intermediate products such as hydrogen fluoride and COF 2, and further hydrogen fluoride and COF 2 react with water. As a result, hydrogen fluoride ions (HF ₂ ⁻ ) as the final product are generated.
Fluorine radicals and fluorine ions (F ⁻ ) have a short lifetime, but hydrogen fluoride is stable. For this reason, hydrogen fluoride can fill the entire chamber. Then, hydrogen fluoride further reacts with water to form hydrogen fluoride ions. Since hydrogen fluoride can fill the entire chamber, hydrogen fluoride ions are generated in the entire chamber. Is done. Since the hydrogen fluoride ions are active, the deposits on the constituent members can be etched.
That is, in the cleaning method of the present invention, hydrogen fluoride ions can be present throughout the chamber. For this reason, the whole structural member mounted in the mounting area can be exposed to hydrogen fluoride ions, and an area with a poor etching rate can be eliminated.
Therefore, in the cleaning method using the remote plasma processing method, the etching rate can be improved, thereby shortening the cleaning time.

  Hereinafter, an embodiment of a cleaning apparatus and method according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

In the present embodiment, a cleaning apparatus and method for cleaning a deposition preventing plate (a constituent member of the film forming apparatus) installed in the processing atmosphere of the film forming apparatus will be described.
Prior to the description of the cleaning apparatus and method of the present embodiment, a film forming apparatus in which a deposition preventing plate is installed will be described.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of the film forming apparatus 100. As shown in this figure, the film forming apparatus 100 includes a chamber 104 to which a vacuum pump 102 is connected. A substrate holder 110 is provided inside the chamber 104. The substrate holder 110 is configured to hold the substrate P to be subjected to film formation processing downward. On the other hand, a crucible 120 filled with a film forming material 124 is provided so as to face the substrate holder 110. The filament 122 is defeated in the crucible 120 so that the film forming material 124 in the crucible can be heated. An adhesion preventing plate 130 for preventing the material released from the crucible 120 from adhering to the inner wall or the like of the chamber 104 is installed. That is, the deposition preventing plate 130 is installed in the processing atmosphere of the film forming apparatus.

  In order to perform a film forming process using such a film forming apparatus, first, the substrate P is mounted on the substrate holder 110 and the crucible 120 is filled with the film forming material 124. Next, the vacuum pump 102 connected to the chamber 104 is operated to evacuate the chamber 104. Next, the filament 122 wired to the crucible 120 is energized to generate heat, and the film forming material 124 in the crucible is heated. Then, the film forming material 124 evaporates and adheres to the surface of the substrate P. In the course of the film forming process, the film forming material scattered in the direction other than the substrate P adheres to the surface of the deposition preventing plate 130. In the present embodiment, the film forming material 124 is silicon oxide.

The deposition preventing plate 130 is detachable from the chamber 104, and is periodically removed, cleaned outside the film forming apparatus 100, and regenerated. FIG. 2 is a cross-sectional view of the deposition preventing plate 130. As shown in this figure, in this embodiment, the adhesion preventing plate 130 includes a base material 131 made of stainless steel and an aluminum layer 132 in which aluminum sprayed on the surface of the base material 131 is solidified. .
The cleaning apparatus and method of the present embodiment are for removing the film forming material 124 that is a deposit attached to the surface of the above-described deposition preventing plate 130.

  FIG. 3 is an overall view schematically showing a schematic configuration of the cleaning apparatus 1 of the present embodiment. As shown in this figure, the cleaning device 1 of the present embodiment includes a chamber 2, an active gas supply device 3 (active gas supply unit), and a water vapor supply device 4 (water supply unit).

The chamber 2 is provided with a deposition plate holder 21 on which the deposition plate 130 can be placed. The deposition plate holder 21 is installed at the bottom of the chamber 2. For this reason, the deposition preventing plate 130 is disposed in the lower part in the chamber 2. That is, in the cleaning apparatus 1 of the present embodiment, the lower portion of the chamber 2 is a placement area on which the deposition preventing plate 130 is placed.
In addition, a plurality of deposition plates 130 can be placed on the deposition plate holder 21. That is, in the cleaning apparatus 1 of the present embodiment, a plurality of deposition plates can be placed on the placement area.
Note that a vacuum pump (not shown) is connected to the chamber 2, and the inside of the chamber 2 is made a vacuum atmosphere by driving the vacuum pump.

The active gas supply device 3 generates an active gas by decomposing a reactive gas containing fluorine with plasma, supplies the active gas G into the chamber 2, and is connected to the upper portion of the chamber 2.
FIG. 4 is a block diagram showing a functional configuration of the active gas supply device 3. As shown in this figure, the active gas supply device 3 includes a reaction gas supply unit 31 and a plasma generation unit 32.
The reactive gas supply unit 31 supplies a reactive gas containing fluorine to the plasma generating unit 32.
The plasma generation unit 32 generates plasma and generates an active gas G (fluorine radical (F ^* ), fluorine ion (F ⁻ )) by decomposing the reaction gas supplied from the reaction gas supply unit 31 by the plasma. Then, it is supplied into the chamber 2. As such a plasma generator 32, for example, a vacuum vessel having an inductively coupled plasma source and a device provided with a high frequency power source can be used.

The water vapor supply device 4 supplies water vapor W (vaporized water (H ₂ 0)) into the chamber 2 and is connected to the upper portion of the chamber 2.
FIG. 5 is a block diagram showing a functional configuration of the water vapor supply device 4. As shown in this figure, the water vapor supply device 4 includes a pressurized tank 41, a gas pressure regulator 42, a liquid mass flow meter 43, a vaporizer 44, a gas mass flow meter 45, a heat exchanger 46, and a hot filter 47. And a pipe heater 48.

The pressurized tank 41 is a tank for storing liquid water, and supplies part of the stored water to the liquid mass flow meter 43 according to the pressure of the push gas supplied via the gas pressure regulator 42. It is.
The gas pressure regulator 42 is connected to the upper part of the pressurization tank 41 and controls the pressure of push gas supplied from the outside.
The liquid mass flow meter 43 supplies liquid water supplied from the pressurized tank 41 to the vaporizer 44 by a predetermined amount.

The gas mass flow meter 45 supplies a carrier gas (for example, Ar) supplied from the outside to the heat exchanger 46 by a predetermined amount.
The heat exchanger 46 heats the carrier gas supplied from the gas mass flow meter 45 and supplies it to the vaporizer 44.

  The vaporizer 44 vaporizes the liquid water supplied from the liquid mass flow meter 43 into water vapor, and promotes vaporization using the carrier gas supplied from the heat exchanger 46.

The hot filter 47 removes water droplets contained in the water vapor by the vaporizer 44, and supplies water vapor (vaporized water) from which the water droplets have been removed to the chamber 2.
The piping heater 48 keeps the temperature of the water vapor discharged from the hot filter 47, and suppresses the generation of water droplets in the water vapor due to a decrease in the temperature of the water vapor.

  Returning to FIG. 3, in the chamber 2, an introduction pipe 5 for guiding the water vapor supplied from the water vapor supply device 4 to the placement region is installed. The introduction pipe 5 is a pipe provided with a plurality of jet outlets for jetting water vapor toward the deposition plate placed in the placement area, and one end thereof is connected to the water vapor supply device 4.

  Next, the operation (cleaning method) of the cleaning apparatus of the present embodiment configured as described above will be described.

First, when the plurality of deposition plates 130 are placed on the deposition plate holder 21 in the chamber 2, a vacuum pump (not shown) is driven, and the chamber 2 is evacuated.
Thus, when the inside of the chamber 2 is in a vacuum atmosphere, the active gas G is supplied from the active gas supply device 3 into the chamber 2, and the water vapor W is supplied from the water vapor supply device 4 into the chamber 2.

  More specifically, in the active gas supply device 3, a reaction gas containing fluorine is supplied from the reaction gas supply unit 31 to the plasma generation unit 32. In the plasma generator 32, plasma is generated, and an active gas G is generated and discharged by the plasma. Then, the discharged active gas G is supplied into the chamber 2.

Further, in the water vapor supply device 4, the pressure in the pressurized tank 41 is controlled by the gas pressure regulator 42, and liquid water stored in the pressurized tank 41 is supplied to the liquid mass flow meter 43 in accordance with this pressure. . Then, a predetermined amount of water is supplied to the vaporizer 44 by the liquid mass flow meter 43.
On the other hand, a predetermined amount of carrier gas is supplied from the gas mass flow meter 45 to the heat exchanger 46. Then, the carrier gas is heated by the heat exchanger 46 and supplied to the vaporizer 44.
When liquid water and a heated carrier gas are supplied to the vaporizer 44, water vaporization of water is promoted, and a desired amount of water vapor is generated. The water vapor generated by the vaporizer 44 is supplied into the chamber 2 after the water droplets are removed by the hot filter 47.

  And the water vapor | steam W supplied from the water vapor | steam supply apparatus 4 is guide | induced to the mounting area | region where the deposition prevention board 130 is mounted by the introductory piping 5, and is ejected toward the deposition prevention board 130 from a jet nozzle.

Thus, the water vapor W supplied into the chamber 2 fills the chamber 2. On the other hand, the active gas G is supplied into the chamber 2 from the active gas supply device 3. The active gas G is a fluorine radical (F ^* ) or a fluorine ion (F ⁻ ) and has a short lifetime, but since the water vapor W is filled in the chamber 2, the water vapor W is supplied immediately in the chamber 2. React with. As a result, hydrogen fluoride (HF) and COF2 which are intermediate products are generated. Since the hydrogen fluoride is stable, the chamber 2 is filled. This hydrogen fluoride further reacts with the water vapor W. As a result, hydrogen fluoride ions (HF ₂ ⁻ ) as the final product are generated. That is, hydrogen fluoride ions are generated throughout the chamber 2. Since the hydrogen fluoride ions are active, the deposits on the constituent members can be etched. For this reason, the whole adhesion prevention board 130 mounted in the mounting area | region can be exposed to hydrogen fluoride ion. Therefore, the film forming material 124 attached to the deposition preventing plate 130 is uniformly etched.

  As described above, according to the cleaning apparatus and method of this embodiment, it is possible to eliminate the region where the etching rate is bad in the mounting region. Therefore, in the cleaning apparatus using the remote plasma processing method, the etching rate can be improved, thereby shortening the cleaning time.

  Further, the cleaning device of the present embodiment includes an introduction pipe 5 that guides the water vapor W supplied by the water vapor supply device 4 to the placement area. For this reason, the reaction between hydrogen fluoride ions and water vapor W can be promoted particularly in the mounting region, and radical hydrogen fluoride can be generated. Etching can be performed. Therefore, the etching rate can be further improved.

  Further, in the cleaning apparatus of the present embodiment, uniform etching can be performed in the chamber 2, so that the deposition preventing plate 130 can be cleaned in a much wider area than the conventional cleaning apparatus. For this reason, in the cleaning apparatus of this embodiment, a plurality of deposition plates 130 can be placed in the placement region. For this reason, a plurality of constituent members can be uniformly and simultaneously cleaned, and the cleaning time can be further shortened.

FIG. 6 is a table showing experimental results in the cleaning apparatus and method of the present embodiment. In the experiment shown in FIG. 4, as shown in FIG. 7, a simple water vapor supply device in which a hot plate was installed in a tank for storing water was used. Then, quartz glass whose half is covered with a masking tape is placed as a sample at the center of the placement area (just below the active gas supply device) and / or the right side (center right) of the center, and the introduction pipe 5 is used. Then, water vapor W was jetted toward the quartz glass placed on the center right. In this experiment, a mixed gas of C ₃ F ₆ and O ₂ was used as the reaction gas, and the flow rates were 600 sccm and 2000 sccm, respectively.

  In Experiment A, the sample was placed only in the center of the placement region without supplying water vapor, and after 10 minutes of treatment, the region was formed by the region masked with the masking tape and the region not formed. The amount of etching was measured by measuring the difference in level. As a result, the etching amount in Experiment A was 533.5 nm.

  Further, in Experiment B, water vapor was supplied, the sample was placed only at the center right of the placement region, and after 10 minutes of treatment, the region was formed by a region masked with a masking tape and a region not formed. The etching amount was measured by measuring the step. As a result, the etching amount in Experiment B was 1218 nm.

  Further, in Experiment C, without supplying water vapor, the sample was placed at the center and the center right of the placement region, and after processing for 10 minutes, the region masked with the masking tape and the region not defined The etching amount was measured by measuring the formed step. As a result, in Experiment C, the etching amount at the center was 502.5 nm, and the etching amount at the center right was 193.5 nm.

Comparing Experiment A and Experiment B shows that the etching rate is improved by supplying water vapor, even in the region where the etching rate is deteriorated in the conventional cleaning apparatus.
Further, when Experiment B and Experiment C were compared, it was found that the etching amount increased about 6 times by supplying water vapor.

  As mentioned above, although the cleaning apparatus and method were demonstrated as one Embodiment of this invention, this invention is not limited to this, Unless it deviates from the range described in each claim, it limits to the description word of each claim. However, it is possible to appropriately add an improvement based on the knowledge that a person skilled in the art normally has, and to the extent that a person skilled in the art can easily replace them.

For example, in the above embodiment, the example in which the deposition preventing plate 130 is configured by the base material 131 and the aluminum layer 132 has been described.
However, the present invention is not limited to this, and the deposition preventing plate 130 may be composed only of a stainless steel base material. In such a case, cleaning can be performed without considering the peeling of the aluminum layer 132.

  Moreover, in the said embodiment, the adhesion prevention board was mentioned as an example of the structural member of the film-forming apparatus, and the method to wash | clean the said adhesion prevention board was demonstrated. However, the present invention is not limited to this, and can also be applied to a method for cleaning other components of the film forming apparatus (for example, a shutter for defining a material passage region). .

It is sectional drawing which shows schematic structure of the film-forming apparatus provided with the adhesion prevention board which wash | cleans with the washing | cleaning apparatus and method which are one Embodiment of this invention. It is sectional drawing of the adhesion prevention board which wash | cleans with the washing | cleaning apparatus and method which are one Embodiment of this invention. It is the whole figure which showed typically schematic structure of the washing | cleaning apparatus which is one Embodiment of this invention. It is a block diagram which shows the function structure of the active gas supply apparatus with which the washing | cleaning apparatus which is one Embodiment of this invention is provided. It is a block diagram which shows the function structure of the water vapor | steam supply apparatus with which the washing | cleaning apparatus which is one Embodiment of this invention is provided. It is a table | surface which shows the experimental result of the washing | cleaning apparatus which is one Embodiment of this invention. It is the whole figure which showed typically schematic structure of the washing | cleaning apparatus used only to obtain the experimental result shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cleaning apparatus, 2 ... Chamber, 3 ... Active gas supply apparatus (active gas supply part), 4 ... Steam supply apparatus (water supply part), 100 ... Film-forming apparatus, 130 ... Anti-adhesion plate (Constituent member), G ... Active gas, W ... Water vapor

Claims (6)

A cleaning apparatus for removing deposits from the surface of a constituent member of a film forming apparatus installed in a processing atmosphere of the film forming apparatus,
A chamber having a placement region on which the component is placed;
An active gas supply unit for generating an active gas by decomposing a reaction gas containing fluorine with plasma, and supplying the active gas into the chamber;
A cleaning apparatus comprising: a water supply unit that supplies vaporized water into the chamber.   The cleaning apparatus according to claim 1, further comprising an introduction pipe for guiding the vaporized water supplied by the water supply unit to the placement area.   The cleaning apparatus according to claim 1, wherein a plurality of the constituent members can be placed in the placement area.   The said structural member consists of stainless steel, The washing | cleaning apparatus in any one of Claims 1-3 characterized by the above-mentioned.   The said structural member is provided with the base material which the said structural member consists of stainless steel, and the aluminum layer which the aluminum sprayed on the surface of this base material solidified, The one in any one of Claims 1-3 characterized by the above-mentioned. Cleaning equipment. A cleaning method for removing deposits from the surface of a constituent member of a film forming apparatus installed in a processing atmosphere of the film forming apparatus,
A cleaning method, wherein an active gas is generated by decomposing a reactive gas containing fluorine with plasma, and the active gas and vaporized water are supplied into a chamber in which the constituent members are placed.

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