JP5528773B2 - Shower head, shower head manufacturing method, and shower head regeneration method - Google Patents

Description

The present invention relates to a shower head used in a plasma processing apparatus, and more particularly to a shower head comprising a laminate of a conductive upper plate and a lower plate having corrosion resistance against plasma.
The present invention also relates to a method for manufacturing and regenerating such a showerhead.

  In processing of a substrate by a dry process, plasma processing is performed in which a reactive gas for generating plasma is supplied above the substrate and a plasma is generated by applying a voltage, and the plasmad reactive gas performs plasma processing on the substrate. The device is being used. In such a plasma processing apparatus, there is a problem in that particles generated in the gas phase and film pieces grown other than the substrate float in the plasma processing space, thereby reducing the quality of the plasma processed substrate. .

  The shower head used in the plasma processing apparatus is also a cause of particle generation. As shown in FIG. 4, the shower head 21 is formed of a laminate in which an upper plate 22 that has conductivity and functions as an electrode and a lower plate 23 that has corrosion resistance against plasma are joined together by brazing material, solder, or the like. A plurality of ejection holes 24 penetrating from the bottom surface to the bottom surface. The reaction gas supplied to the upper plate 22 side of the shower head 21 is uniformly supplied from the plurality of ejection holes 24 toward the substrate, and a voltage is applied to the upper plate 22 to generate plasma. Due to the temperature change caused by the generation of the plasma, friction is generated between the upper plate 22 and the lower plate 23 due to the difference in thermal expansion coefficient between the two as shown by arrows in FIG.

  Thus, for example, Patent Document 1 discloses that particles or film pieces generated as a by-product in the space during film formation of a substrate fall down to the bottom surface and gather near a gas exhaust port for exhausting a reaction gas. Powder scattering prevention devices have been proposed. In this powder scattering prevention device, the airflow is subdivided by the honeycomb-shaped perforated plate, thereby suppressing the particles accumulated on the bottom surface from flying up with the airflow.

Japanese Patent Laid-Open No. 08-013150

  However, the fundamental problem of suppressing the generation of particles has not been solved. In particular, the particles generated by the shower head are generated above the substrate. It was difficult.

The present invention has been made to solve such a conventional problem, and provides a shower head capable of buffering friction generated between an upper plate and a lower plate and suppressing generation of particles. For the purpose.
Another object of the present invention is to provide a method for manufacturing and regenerating such a showerhead.

In order to achieve the above object, a shower head according to the present invention ejects a gas supplied from a gas supply source into a plasma generation space through a plurality of ejection holes and generates a voltage for generating plasma in the ejected gas. A shower head that functions as an electrode for applying a gas, comprising an upper plate having conductivity, a lower plate having corrosion resistance against plasma, a fluorine-containing ethylenic polymer having a hydroxyl group, and the upper plate and the Heat that joins the upper plate and the lower plate to each other by interposing between the lower plate and the upper plate and the lower plate so as to buffer friction when the shapes of the upper plate and the lower plate change due to thermal expansion on a smooth surface. and a fusing sheet, the upper plate, the lower plate and the heat-fusible sheet has a plurality of through holes corresponding to the plurality of jetting holes, the heat A plurality of through-holes formed in the sheet is characterized by having a larger diameter than each of said upper plate and a plurality of through-holes formed in the lower plate.

The method for manufacturing a showerhead according to the present invention also includes an electrode for injecting a gas supplied from a gas supply source into a plasma generation space through a plurality of injection holes and applying a voltage for generating plasma to the injected gas. A showerhead manufacturing method for manufacturing a showerhead that functions as a plurality of through holes corresponding to the plurality of ejection holes in the upper plate and the lower plate, respectively, and corresponding to the plurality of ejection holes. A plurality of through-holes having a diameter larger than the plurality of through-holes formed in the upper plate and the lower plate are formed in the heat-sealing sheet, and the upper plate having conductivity and the lower plate having corrosion resistance against plasma. preparative shape thermal expansion of the lower plate configured heat-fusible sheet and the upper plate from fluorine-containing ethylenic polymer having hydroxyl groups between them Friction is interposed so as to buffer a smooth surface when changing more mutually, said positions of said plurality of through-holes formed in the respective match the upper plate, the heat-fusible sheet, and the lower plate The upper plate and the lower plate are joined to each other by heat fusion of the heat fusion sheet.

Also, the showerhead regeneration method according to the present invention is an electrode for injecting a gas supplied from a gas supply source into a plasma generation space through a plurality of injection holes and applying a voltage for plasma generation to the injected gas. A shower head regeneration method for regenerating a shower head that functions as an upper plate having conductivity and a plurality of through holes corresponding to the plurality of ejection holes, and a surface facing the plasma generation space. A lower plate having a plurality of through holes corresponding to the plurality of ejection holes, and a fluorine-containing ethylenic polymer having a hydroxyl group, and formed on the upper plate and the lower plate, respectively. wherein said upper plate between the plurality of through-holes having a Rutotomoni said upper plate and said lower plate having a larger diameter than said plurality of through-holes And a heat-sealing sheet shape parts plate is interposed joined together and said lower plate and said upper plate so as to buffer frictionally a smooth surface when changing from one another due to thermal expansion, the spent of the The shower head is heated to melt or soften the heat sealing sheet, the upper plate and the lower plate are separated from each other, one of the upper plate and the lower plate is replaced with a new one, and the other is The one upper plate or the lower plate to be reused and the other upper plate or the lower plate to be reused are composed of a fluorine-containing ethylenic polymer having a hydroxyl group therebetween, and the upper portion of the one the new thermal fusion sheet that having a plurality of through holes than the plurality of through holes respectively formed with the plate or the lower plate to the upper plate or lower plate of the other with a larger diameter whereas Positions of the plurality of through holes friction is interposed so as to buffer a smooth surface, is formed in each case the shape of the upper plate or the lower plate and the other of the upper plate or the lower plate are changed each other by thermal expansion The one upper plate or the lower plate, the heat fusion sheet, and the other upper plate or the lower plate are laminated, and a new one upper portion is obtained by heat fusion of the new heat fusion sheet. The plate or the lower plate and the other upper plate or the lower plate to be reused are joined to each other.
Here, after the used shower head is heated and separated from each other into the upper plate and the lower plate, the other upper plate or the lower plate to be reused is reused by cleaning. It may be joined to the one upper plate or the lower plate.

  According to the present invention, the friction generated between the upper plate and the lower plate can be buffered and the generation of particles can be suppressed.

It is sectional drawing which shows the structure of the plasma processing apparatus provided with the shower head which concerns on one Embodiment of this invention. It is a disassembled perspective view which shows the structure of a shower head. It is sectional drawing which shows the structure of a shower head. It is sectional drawing which shows the structure of the conventional shower head.

  Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  In FIG. 1, the structure of the plasma processing apparatus provided with the shower head 1 which concerns on one Embodiment of this invention is shown. The plasma processing apparatus has a vacuum chamber 2 that keeps the inside airtight from the outside.

  A gas supply port 3 for supplying a reaction gas is installed on the upper surface in the vacuum chamber 2, and a gas exhaust port 4 for exhausting the reaction gas is installed on the lower surface in the vacuum chamber 2. The gas supply port 3 is connected to a gas supply source (not shown), and a reaction gas for generating plasma by the gas supply source is supplied into the vacuum chamber 2 through the gas supply port 3. Further, the gas exhaust port 4 is connected to a decompression device (not shown), and the vacuum chamber 2 has a predetermined degree of vacuum by the decompression device, and the vacuum chamber 2 has a predetermined degree of vacuum even when the reaction gas is supplied. Make adjustments to maintain. As the decompression device, a vacuum pump, a cryocoil, or the like can be used.

The gas supply port 3 is connected to a shower head holding member 5 formed of a conductive material. The shower head holding member 5 has a gas supply chamber 6 that is a hollow space inside, and a reaction gas is supplied to the gas supply chamber 6 from the gas supply port 3. The shower head holding member 5 and the vacuum chamber 2 are electrically insulated from each other.
The shower head 1 is attached to the lower side of the shower head holding member 5 so as to cover the lower surface of the gas supply chamber 6. The shower head 1 is formed with a plurality of ejection holes 7 penetrating from the upper surface to the lower surface, and the reaction gas supplied from the gas supply chamber 6 is ejected below the shower head 1 through the plurality of ejection holes 7. Is done. The shower head 1 has an upper electrode made of a conductive material, and a plasma generation space P is formed below the shower head 1.

  In the lower part of the vacuum chamber 2, a holding table 8 is installed with the plasma generation space P sandwiched between the plasma head and the shower head 1. A lower electrode and an electrostatic chuck electrode are installed inside the holding table 8. The lower electrode is installed in parallel with the upper electrode of the showerhead 1 and is grounded. As a result, the lower electrode of the holding table 8 and the upper electrode of the shower head 1 form an electrode pair for generating plasma. On the other hand, the electrostatic chuck electrode is installed on the upper part of the holding table, and generates an electrostatic force with the substrate S installed on the upper surface of the holding table 8 when a voltage is applied from a high voltage DC power source (not shown). Then, the substrate S is fixed to the holding table 8. The holding table 8 and the vacuum chamber 2 are electrically insulated from each other.

  The upper electrode of the shower head 1 is connected to a high frequency power source 9 via a shower head holding member 5. The high-frequency power source 9 is a power source that supplies power for generating plasma, and a known high-frequency power source used in a plasma processing apparatus can be used.

FIG. 2 shows the configuration of the shower head 1. The shower head 1 is composed of a laminate of an upper plate 10, a heat fusion sheet 11, and a lower plate 12 each having a disk shape.
The upper plate 10 is formed of a conductive material and is connected to the high-frequency power source 9 through the shower head holding member 5 and functions as an upper electrode that makes a pair with the lower electrode of the holding table 8. For example, silicon (Si), metal matrix composite (MMC), silicon carbide (SiC), or the like can be used as the conductive material for forming the upper plate 10. In the upper plate 10, a plurality of through holes 13 penetrating from the upper surface to the lower surface are formed corresponding to the plurality of ejection holes 7 formed in the shower head 1. The diameter of the plurality of through holes 13 formed in the upper plate 10 is preferably 2 to 0.5 mm.
The lower plate 12 is formed of a material having corrosion resistance against plasma and generating less particles. For example, silicon carbide (SiC), yttrium oxide (Y ₂ O ₃ ), or the like can be used. The lower plate 12 is formed with a plurality of through holes 14 penetrating from the upper surface to the lower surface corresponding to the plurality of ejection holes 7 formed in the shower head 1, and the diameter of the plurality of through holes 14 is as follows. For example, it is preferably about 0.5 mm.

  The heat-sealing sheet 11 is formed of a fluorine-containing polymer that is interposed between the upper plate 10 and the lower plate 12 to buffer the friction between them, and joins the upper plate 10 and the lower plate 12 to each other by heat-sealing. Is done. As the fluorine-containing polymer forming the heat-sealing sheet 11, for example, a fluorine-containing ethylenic polymer having a hydroxyl group disclosed in Japanese Patent No. 3885805 can be used. A plurality of through holes 15 penetrating from the upper surface to the lower surface are formed in the heat sealing sheet 11 corresponding to the plurality of ejection holes 7 formed in the shower head 1. The diameters of the plurality of through holes 15 formed in the heat-sealing sheet 11 are preferably larger than the through holes of the upper plate 10 and the lower plate 12, and preferably have a diameter of 2 to 5 mm, for example. .

A plurality of through holes 13, 15, 14 as described above are formed in each of the upper plate 10, the heat sealing sheet 11, and the lower plate 12, and the positions of these through holes 13, 15, 14 are aligned with each other to form an upper portion. The upper plate 10 and the lower plate 12 are joined to each other by the heat fusion sheet 11 by laminating the plate 10, the heat fusion sheet 11 and the lower plate 12 and heating them at 300 to 350 ° C. for 10 to 20 minutes. can do.
In addition, the shower head 1 heat-sealed in this way is heated from 300 to 350 ° C. in the same manner to melt or soften the heat-sealing sheet 11 so that the heat is applied from the upper plate 10 and the lower plate 12. The fusing sheet 11 can be removed.
As shown in FIG. 3, the shower head 1 having such a configuration is attached so as to cover the lower surface of the gas supply chamber 6 with the upper plate 10 of the shower head 1 as an upper surface, Are connected via a shower head holding member 5. The reaction gas supplied from the gas supply source to the gas supply chamber 6 is ejected below the shower head 1 through a plurality of ejection holes 7 formed in the shower head 1.

  Next, the operation of the plasma processing apparatus provided with the shower head 1 shown in FIG. 1 will be described.

First, the shower head 1 composed of a laminate of an upper plate 10, a heat sealing sheet 11, and a lower plate 12 covers the gas supply chamber 6 provided in the vacuum chamber 2 with the upper plate 10 as the upper surface. Attached to the shower head holding member 5. The holding table 8 holds the substrate S by the action of the electrostatic chuck.
Subsequently, the air in the vacuum chamber 2 is exhausted from the gas exhaust port 4 by the decompression device, and when the inside of the vacuum chamber 2 reaches a predetermined degree of vacuum, the reaction gas is supplied from the gas supply source to the gas supply chamber 6. The decompression device adjusts the exhaust in the vacuum chamber 2 so that the inside of the vacuum chamber 2 has a predetermined degree of vacuum even when the reaction gas is supplied.

The reaction gas supplied to the gas supply chamber 6 is ejected between the shower head 1 and the substrate S through a plurality of ejection holes 7 formed in the shower head 1. On the other hand, a voltage is applied to the upper plate 10 of the shower head 1 from the high frequency power source 9 through the shower head holding member 5. Thus, an electrode pair is formed by the upper plate 10 of the shower head 1 and the lower electrode of the holding table 8, and the reactive gas ejected between them is excited to generate plasma.
The surface of the substrate S is exposed to the plasma thus generated, and the substrate S is subjected to plasma treatment.

  Here, due to a temperature change due to the generation of plasma, the shape of the upper plate 10 and the lower plate 12 changes due to the difference in thermal expansion coefficient. By buffering the friction, the generation of particles can be suppressed, and the quality of the plasma processing surface can be improved.

When the plasma processing is completed, the next substrate S is held on the holding table 8 and the same operation is repeated. Here, the lower plate 12 of the showerhead 1 has corrosion resistance to plasma, but the lower plate 12 may be corroded by being exposed to the plasma for a long time. Even in such a case, the shower head 1 can be regenerated by exchanging only the corroded lower plate 12 and reusing the usable upper plate 10 by the peelable heat-sealing sheet 11.
For example, the shower head 1 is removed from the shower head holding member 5 and heat treatment is performed at 300 to 350 ° C. until the heat-sealing sheet 11 is melted or softened, thereby separating the upper plate 10 and the lower plate 12 from each other. Subsequently, the corroded lower plate 12 is replaced with a new one, and the cleaned upper plate 10, the new heat-sealing sheet 11, and the new lower plate 12 are stacked, and 10 to 20 at 300 to 350 ° C. The shower head 1 can be regenerated by performing a heat treatment for a minute and joining the reused upper plate 10 and new lower plate 12 by heat fusion of the heat fusion sheet 11.
Further, the upper plate 10 of the shower head 1 may be corroded by being exposed to the reaction gas for a long time. With the sheet 11, the shower head 1 can be regenerated by replacing only the corroded upper plate 10 and reusing the usable lower plate 12.

In this way, even if one of the upper plate 10 and the lower plate 12 constituting the shower head 1 is corroded, the debris of the heat-sealing sheet 11 attached to the other usable upper plate 10 or lower plate 12 is washed, etc. The shower head 1 can be regenerated by simply removing it by performing a simple process, and the shower head 1 can be regenerated by a simple operation.
The other upper plate 10 or the lower plate 12 that can be used in the present embodiment is reused by washing, but the other upper plate 10 or the lower plate 12 can be used for the heat fusion sheet 11 or the like. It is only necessary that the deposits can be removed. For example, the surface may be scraped or polished to be reused.

  The regenerated shower head 1 is attached to the shower head holding member 5 in the vacuum chamber 2 and used in the same manner until one of the upper plate 10 and the lower plate 12 is corroded again.

  According to the shower head of the present embodiment, the heat-bonding sheet 11 can suppress the generation of particles by buffering the friction between the upper plate 10 and the lower plate 12, and the quality of the plasma-treated substrate S can be reduced. It becomes possible to improve. Moreover, even if one of the upper plate 10 or the lower plate 12 constituting the shower head 1 is corroded, the other usable upper plate 10 or lower plate 12 can be reused simply by performing a process such as cleaning. The shower head 1 can be regenerated by a simple operation.

  In the present embodiment, the shower head is formed with a plurality of through holes in each of the upper plate, the heat fusion sheet, and the lower plate, and the positions of these through holes are aligned with each other to form the upper plate with the heat fusion sheet. The upper plate and the lower plate are joined to each other. After the upper plate, the heat fusion sheet, and the lower plate are laminated and the upper plate and the lower plate are joined to each other by the heat fusion sheet, the upper plate is changed from the upper surface to the lower surface. You may form the several jet hole which penetrates.

  In this embodiment, the shower head is used in a plasma processing apparatus that performs plasma processing on a substrate using a reactive gas. However, the shower head is also generated on the semiconductor substrate using a source gas together with the reactive gas. The present invention can be similarly applied to a semiconductor manufacturing apparatus that forms a film, and it is possible to form a high-quality film by suppressing generation of particles.

1,21 Shower head, 2 Vacuum chamber, 3 Gas supply port, 4 Gas exhaust port, 5 Shower head holding member, 6 Gas supply chamber, 7,24 Ejection hole, 8 Holding stand, 9 High frequency power supply, 10,22 Upper plate , 11 Thermal fusion sheet, 12, 23 Lower plate, 13, 14, 15 Through hole, S substrate, P Plasma generation space

Claims (4)

A shower head that functions as an electrode for injecting a gas supplied from a gas supply source into a plasma generation space through a plurality of injection holes and applying a voltage for plasma generation to the injected gas,
A conductive upper plate;
A lower plate having corrosion resistance to plasma;
It is composed of a fluorine-containing ethylenic polymer having a hydroxyl group, and friction between the upper plate and the lower plate when the shape of the upper plate and the lower plate changes from each other due to thermal expansion on a smooth surface. A heat-sealing sheet for interposing the upper plate and the lower plate so as to cushion each other , and
The upper plate, the lower plate, and the heat sealing sheet each have a plurality of through holes corresponding to the plurality of ejection holes, and the plurality of through holes formed in the heat sealing sheet are respectively the upper part. A shower head having a diameter larger than a plurality of through holes formed in the plate and the lower plate . A shower head manufacturing method for manufacturing a shower head that functions as an electrode for applying a voltage for generating plasma to a gas generated by ejecting a gas supplied from a gas supply source to a plasma generation space through a plurality of ejection holes Because
A plurality of through holes corresponding to the plurality of ejection holes are formed in the upper plate and the lower plate, respectively, and the plurality of penetrations corresponding to the plurality of ejection holes and formed in the upper plate and the lower plate Forming a plurality of through-holes having a diameter larger than the holes in the heat-sealing sheet,
A heat-bonded sheet composed of a fluorine-containing ethylenic polymer having a hydroxyl group between an upper plate having conductivity and a lower plate having corrosion resistance against plasma is formed between the upper plate and the lower plate. The upper plate, the heat-sealing sheet, and the lower plate are arranged such that friction when they change from each other due to expansion is buffered by a smooth surface, and the positions of the plurality of through holes formed in each of them are matched. the laminated,
The method of manufacturing a shower head, wherein the upper plate and the lower plate are joined to each other by heat fusion of the heat-fusion sheet. A shower head regeneration method for regenerating a shower head functioning as an electrode for applying a voltage for generating plasma to a gas generated by ejecting a gas supplied from a gas supply source to a plasma generation space through a plurality of ejection holes Because
The shower head is
An upper plate having conductivity and a plurality of through holes corresponding to the plurality of ejection holes ;
A lower plate disposed to face the plasma generation space and having a plurality of through holes corresponding to the plurality of ejection holes ;
And Rutotomoni said upper plate having a plurality of through-holes having a larger diameter than the fluorine-containing ethylenic consists polymer and the upper plate and the plurality of through-holes formed respectively in said lower plate having a hydroxyl group The upper plate and the lower plate are joined to each other by interposing between the lower plate and the upper plate and the lower plate so as to cushion friction when the shapes of the upper plate and the lower plate change from each other due to thermal expansion on a smooth surface. A heat-sealing sheet,
Heating the used shower head to melt or soften the heat-sealing sheet,
Separating the upper plate and the lower plate from each other;
Replace one of the upper plate and the lower plate with a new one and reuse the other,
The other of the upper plate or the lower plate and the fluorine-containing ethylenic is composed of a polymer and an upper plate or the lower portion of the one having a hydroxyl group between these to and reuse new one of the upper plate or the lower plate a plurality of said new thermal fusion sheet that having a through hole one of the upper plate or the lower plate having a larger diameter than said plurality of through-holes formed respectively said the other of the upper plate or the lower plate and plate The other upper plate or the lower plate is interposed so as to buffer the friction when the shape of the other upper plate or the lower plate changes from each other due to thermal expansion with a smooth surface, and the positions of the plurality of through holes formed in the respective ones are matched. Laminating the upper plate or lower plate, the heat fusion sheet, and the other upper plate or lower plate ,
A method of regenerating a showerhead, comprising joining one new upper plate or lower plate and the other upper plate or lower plate to be reused together by heat-sealing the new heat-sealing sheet. After the used shower head is heated and separated from each other into the upper plate and the lower plate, the other upper plate or the lower plate to be reused is reused by washing, and the new one The shower head regeneration method according to claim 3 , wherein the shower head is joined to an upper plate or a lower plate.

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