WO2019097875A1 - Appareil de tirage de monocristal et procédé de tirage de monocristal de silicium - Google Patents

Appareil de tirage de monocristal et procédé de tirage de monocristal de silicium Download PDF

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Publication number
WO2019097875A1
WO2019097875A1 PCT/JP2018/036992 JP2018036992W WO2019097875A1 WO 2019097875 A1 WO2019097875 A1 WO 2019097875A1 JP 2018036992 W JP2018036992 W JP 2018036992W WO 2019097875 A1 WO2019097875 A1 WO 2019097875A1
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WIPO (PCT)
Prior art keywords
quartz crucible
single crystal
silicon
pulling
heat shield
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PCT/JP2018/036992
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English (en)
Japanese (ja)
Inventor
清隆 高野
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信越半導体株式会社
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Publication date
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Publication of WO2019097875A1 publication Critical patent/WO2019097875A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/20—Controlling or regulating
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/02—Elements
    • C30B29/06—Silicon

Definitions

  • the present invention relates to a single crystal pulling apparatus and a method of pulling a silicon single crystal.
  • Carbon is contained as an impurity in a silicon single crystal substrate widely used as a substrate of a semiconductor device. Carbon is mixed in the process of manufacturing a silicon single crystal, and may also be mixed in a wafer processing process, an epitaxial growth process, and a device manufacturing process.
  • Carbon in a silicon single crystal is normally present at a lattice position of silicon (carbon present at the lattice position is referred to as substituted carbon), and itself is electrically inactive.
  • substituted carbon carbon present at the lattice position
  • interstitial carbon carbon existing at the interstitial position is called interstitial carbon
  • a large number of parts made of graphite are disposed inside the single crystal pulling apparatus because of excellent heat resistance and the like.
  • a graphite crucible, a heater, a heat insulating material, etc. Mixing of carbon into silicon single crystal is caused by the diffusion from the polycrystalline silicon which is the raw material, and the CO gas generated by the reaction between the SiO gas evaporating from the silicon melt (melt) and the graphite parts, into the silicon melt. Occur.
  • the latter reaction becomes remarkable as the concentration of SiO gas in the gas increases and the temperature of the graphite parts in contact with it increases, so it is an issue to suppress the diffusion of CO gas into the silicon melt especially in the latter half of melting of silicon raw materials. It has become.
  • Non-Patent Document 1 numerical calculation indicates that the concentration of carbon dissolved in silicon melt can be reduced by decreasing the furnace internal pressure in the melting step or increasing the Ar gas flow rate. Further, Patent Document 1 describes that carbon reduction is achieved by using a graphite component coated with SiC above the silicon melt. However, the effect was insufficient.
  • the present invention aims to provide a single crystal pulling apparatus capable of suppressing the mixing of carbon into a silicon single crystal to be pulled up.
  • a chamber a graphite crucible disposed inside the chamber, capable of moving up and down, and having a quartz crucible fitted inside, a periphery of the graphite crucible and the quartz crucible And a solid silicon raw material is accommodated in the quartz crucible, and the solid silicon raw material is heated by the heater to form a silicon melt, and a seed crystal is attached to the silicon melt and rotated.
  • the single crystal pulling apparatus for pulling a silicon single crystal by pulling, the single crystal pulling apparatus is located inside the chamber, above the quartz crucible, and when pulling the silicon single crystal from the silicon melt.
  • the upper end of the quartz crucible is smaller than the inner diameter of the upper end of the British crucible, and when the quartz crucible is raised, the upper end of the quartz crucible is not in contact with the first heat shield than the lower end of the first heat shield
  • a second heat shield located above the heater to raise the quartz crucible, and the upper end of the quartz crucible is the first thermal shield.
  • the second heat shield and the upper end of the quartz crucible are configured not to be in contact with each other when located at a position higher than the lower end of the shield, and is larger than the outer diameter of the first heat shield.
  • An annular gas flow control plate having a large inner diameter is provided, and the gas flow control plate is vertically movable between at least the same height as the lower end of the first heat shield and the lower end of the second heat shield.
  • Single crystal pulling that is characterized by To provide a raising apparatus.
  • the single crystal pulling apparatus having such a gas straightening vane can rectify the flow of gas by the gas straightening vane. By rectifying the gas, it is possible to suppress the mixing of carbon into the silicon melt contained in the quartz crucible and the silicon single crystal to be pulled up.
  • the gas rectifying plate be a substrate obtained by coating a pyrolytic carbon film or a SiC film on a base made of isotropic graphite, or a transparent quartz.
  • a storage step of storing the solid silicon source in the quartz crucible using any of the single crystal pulling apparatus described above, and heating the solid silicon source by the heater to form the silicon melt and The silicon melting step, the seeding step of depositing the seed crystal on the silicon melt, and the pulling step of pulling up the silicon single crystal by pulling up while rotating the seed crystal deposited on the silicon melt A method for pulling a single crystal, wherein the position of the quartz crucible is lower than the position of the quartz crucible in the seeding step, and the output of the heater is higher than that of the seeding step.
  • a silicon according to the present invention is characterized in that it is lowered immediately above the quartz crucible with the same height as the lower end of the first heat shield as the lower limit. To provide a method for pulling a single crystal.
  • the gas straightening plate directly above the quartz crucible with the lower end position of the first heat shield as the lower limit.
  • the gas straightening plate can be raised according to the rise of the quartz crucible.
  • the pulling step can be performed in a state where the gas straightening plate is raised to the upper limit of the movable range, or the quartz crucible can be raised and the gas straightening plate can be raised.
  • the gas straightening plate is raised to the upper limit of the movable range, or when the quartz crucible is raised to a position higher than the position of the quartz crucible in the seeding step.
  • the single crystal pulling apparatus of the present invention can rectify the flow of gas by means of the gas straightening plate.
  • the gas straightening plate is directly on the quartz crucible when the position of the quartz crucible is lower than the position of the quartz crucible in the seeding step and the output of the heater is higher than that in the seeding step. By lowering it, it is possible to effectively suppress the mixing of carbon.
  • FIG. 1 is a schematic cross-sectional view showing an example of the single crystal pulling apparatus of the present invention.
  • the single crystal pulling apparatus 10 includes a chamber 11. Furthermore, inside the chamber 11, a graphite crucible 13 is disposed.
  • the graphite crucible 13 is generally placed on the shaft 14 for the graphite crucible and the pedestal 15, and is configured to be vertically movable and rotatable by a crucible lifting mechanism and a rotating mechanism (not shown).
  • the quartz crucible 16 is fitted inside the graphite crucible 13.
  • a heater 17 surrounding the graphite crucible 13 and the quartz crucible 16 is provided around the graphite crucible 13, a heater 17 surrounding the graphite crucible 13 and the quartz crucible 16 is provided.
  • the heater 17 is supported by a heater shaft 18.
  • the single crystal pulling apparatus 10 of the present invention may further include heat insulating members 21 to 26 made of carbon or the like in each part in the chamber.
  • a solid silicon raw material for example, polycrystalline silicon
  • the solid silicon raw material is heated by the heater 17 to form a silicon melt (melt) 51.
  • FIG. 1A shows a state in which a solid silicon raw material is used as a silicon melt 51.
  • this single crystal pulling apparatus 10 pulls up a silicon single crystal by bringing the seed crystal 71 into contact with the silicon melt 51 and pulling it while rotating it. .
  • the seed crystal 71 is attached to the seed crystal holder 61 and pulled up by a wire 62 or the like.
  • the single crystal pulling apparatus 10 of the present invention is disposed in the chamber 11 above the quartz crucible 16 and disposed at a position surrounding the silicon single crystal 72 when pulling up the silicon single crystal 72 from the silicon melt 51.
  • the first cylindrical heat shield 31 is provided.
  • the outer diameter of the first thermal shield 31 is smaller than the inner diameter of the upper end of the quartz crucible 16, and when the quartz crucible 16 is raised, the quartz crucible 16 and the first thermal shield 31 do not come into contact with each other.
  • the upper end of the first heat shield 31 can be positioned higher than the lower end of the first heat shield 31 (see FIGS. 1B and 1C).
  • the single crystal pulling apparatus 10 of the present invention comprises a second heat shield 32 located above the heater 17.
  • the second heat shield 32 does not contact the upper end of the quartz crucible 16 As such, this second heat shield 32 is configured.
  • first heat shield 31 and the second heat shield 32 do not come in contact with each other even if the quartz crucible 16 is raised together with the graphite crucible 13 during pulling up of the silicon single crystal 72.
  • the material of the first heat shield 31 and the second heat shield 32 can be made of, for example, graphite.
  • the single crystal pulling apparatus 10 of the present invention comprises a gas straightening plate 41.
  • the gas straightening vane 41 has an annular shape having an inner diameter larger than the outer diameter of the first heat shield 31.
  • the gas straightening vane 41 can move up and down between at least the same height as the lower end of the first heat shield 31 and the lower end of the second heat shield 32.
  • the gas flow straightening plate 41 is connected to the gas flow straightening plate lifting means 45 by a gas flow straightening plate shaft 43, and the gas flow straightening plate 41 can be moved up and down by moving the gas flow straightening plate lifting means 45 up and down.
  • the lifting and lowering device of the gas straightening vane 41 can be a mechanism as illustrated in FIG. In FIG. 2, in order to make it easy to see, the same reference numerals as those shown in FIG. 1 are appropriately omitted.
  • FIG. 2A shows an example in which the gas flow straightening plate 41 is in the lowered state
  • FIG. 2B shows an example in which the gas flow straightening plate 41 is in the raised state.
  • the shaft 43 on which the gas straightening plate 41 is suspended is fixed to a plate (gas straightening plate raising and lowering plate) 46 of the lifting device.
  • a cylindrical welded bellows 47 is attached to the plate 46, whereby the inside of the bellows 47 has the same atmosphere as the inside of the chamber.
  • the plate 46 is a disk, and has two through holes and a screw hole in the outer peripheral part, and a shaft 48 for mechanically supporting the lifting device outside the bellows 47 is inserted in the through hole, and a ball shaft is in the screw hole. 50 is inserted.
  • the ball shaft 50 is connected to a motor 49 at the top of the lifting device, and by operating the motor 49, the disk-like plate 46 is lifted and lowered, and the gas straightening plate 41 can also be moved vertically.
  • the gas rectifying plate 41 is preferably a substrate made of isotropic graphite coated with a pyrolytic carbon film or a SiC film, or preferably made of transparent quartz. This is because the mixing of carbon into the silicon melt 51 contained in the quartz crucible 16 and the silicon single crystal 72 to be pulled up can be suppressed more effectively.
  • the present invention provides a method of pulling a silicon single crystal using the single crystal pulling apparatus shown in FIG. 1 and FIG.
  • the method of pulling up the silicon single crystal includes a housing process of housing a solid silicon raw material in a quartz crucible 16 and a melting process of heating the solid silicon raw material with a heater 17 to form a silicon melt 51 (FIG. a) and a seeding step (FIG. 1 (b)) in which the seed crystal 71 is deposited on the silicon melt 51 and the silicon single crystal 72 by pulling up while rotating the seed crystal 71 deposited on the silicon melt 51. And pulling up (Fig. 1 (c)).
  • the position of the quartz crucible is lower than the position of the quartz crucible in the seeding step (FIG.
  • the gas straightening plate 41 is lowered directly above the quartz crucible 16 with the same height as the lower end of the first heat shield 31 as the lower limit. More specifically, as shown in FIG. 1A, in the melting step, the gas straightening plate 41 is lowered directly above the quartz crucible 16 with the lower end position of the first heat shield 31 as the lower limit. deep.
  • Such a method of pulling up a silicon single crystal can more effectively suppress the contamination of carbon into the silicon melt 51 contained in the quartz crucible 16 and the silicon single crystal 72 to be pulled up.
  • one or both of the seeding step and the pulling step may be performed in the state where the gas straightening plate 41 is raised to the upper limit of the movable range.
  • the gas straightening plate 41 can be raised according to the rise of the quartz crucible 16.
  • the pulling process FIG. 1C
  • the quartz crucible 16 can be raised and the gas straightening plate 41 can be raised.
  • the raw material for silicon single crystal pulling is generally massive solid silicon polycrystal. Since the bulk specific gravity of polycrystalline silicon is small, it is necessary to lower the crucible (quartz crucible and the graphite crucible holding the quartz crucible) in the melting step more than in the pulling step. However, even if a large amount of inert Ar gas is flowed in this state, the gas containing SiO flows into the moving space at the top of the crucible, and it is calculated that the CO gas generated here is diffused in the silicon melt. It became clear.
  • the present invention provides a single crystal pulling apparatus 10 having a vertically movable gas straightening plate 41 for straightening the gas flowing into the moving space at the top of the crucible, and a manufacturing method using the same.
  • a gas straightening plate 41 is lowered downward to rectify the gas, and the gas straightening plate 41 is raised after melting so that it does not get in the way when pulling up the silicon single crystal 72. It will also be possible to pull up.
  • FIG. 5 The analysis results are shown in FIG. 5 for the conventional example and in FIG. 3 for the example of the present invention.
  • the left figure shows the temperature distribution in the furnace and the gas flow (arrows), and the right figure shows the CO concentration in the gas.
  • the silicon single crystal 72 was pulled using the single crystal pulling apparatus 10 of the present invention shown in FIGS.
  • the pulling conditions were as follows. ⁇ Diameter of quartz crucible 16: 32 inches (approximately 800 mm) ⁇ Raw material charge of polycrystalline silicon: 400 kg ⁇ Diameter of silicon single crystal 72 to pull up: 306 mm
  • the shape of the gas straightening plate 41 the inside diameter is the outer diameter +10 mm of the first heat shield 31, the outside diameter is the inside diameter -10 mm of the cylindrical heat insulating member 21 surrounding the heater 17, and the thickness 10 mm.
  • -Material of gas straightening vane 41 Use isotropic graphite coated with pyrolytic carbon about 50 ⁇ m.
  • the gas straightening vane 41 has two screw holes at equal intervals of 180 degrees, and a shaft 43 made of C / C (carbon composite) material is screwed there via a heat shield. It fixed it with. The shaft 43 penetrates the chamber 11 and is attached to the baffle plate elevating means 45.
  • the position of the quartz crucible 16 is set lower than the position in the seeding process from the initial stage of melting.
  • the gas straightening plate 41 was placed at the same height as the lower end of the first heat shield 31 and at a position higher by 10 mm or more from the upper end of the quartz crucible 16 to perform melting.
  • the seeding process is started after raising the gas straightening plate 41 to the upper end position in synchronization with raising the crucible to the seeding position when melting is completed.
  • the measurement of carbon concentration was performed as follows. Concentration of carbon in crystal: The concentration of carbon at a 70% solidification ratio of the silicon single crystal 72 pulled up was measured by pulling three silicon single crystals 72 at a time. As a result, in the example of the present invention, the carbon concentration was 1.0 ⁇ 10 14 atoms / cm 3 (average of three). This became about 30% low carbonization compared with the comparative example mentioned later.
  • the silicon single crystal 72 was pulled using the conventional single crystal pulling apparatus 100 shown in FIGS. 4 (a) to 4 (c).
  • the single crystal pulling apparatus 100 shown in FIG. 4 is the same as the single crystal pulling apparatus 10 shown in FIG. 1 except that it does not have a mechanism for moving the gas straightening plate 41 and the gas straightening plate 41 up and down.
  • pulling conditions were made to be the same as that of Example, rectification by the gas straightening vane 41 was not performed.
  • the position of the quartz crucible 16 is made lower than the position in the seeding process from the initial stage of melting. The crucible position was lowered and raised to the seeding position at the end of melting.
  • the present invention is not limited to the above embodiment.
  • the above embodiment is an exemplification, and it has substantially the same configuration as the technical idea described in the claims of the present invention, and any one having the same function and effect can be used. It is included in the technical scope of the invention.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

La présente invention concerne un appareil de tirage de monocristal comprenant : une chambre ; un creuset en graphite qui peut être soulevé et abaissé et dans lequel un creuset en quartz est placé ; et un dispositif de chauffage. Un premier corps de protection thermique cylindrique est fourni de manière à être disposé à l'intérieur de la chambre de manière à entourer un monocristal de silicium lorsque ledit monocristal de silicium est tiré d'une masse fondue de silicium. L'invention comprend également un second corps de protection thermique qui est positionné au-dessus du dispositif de chauffage et qui, lorsque le creuset en quartz est soulevé, est apte à positionner l'extrémité supérieure du creuset en quartz à une position plus élevée que l'extrémité inférieure du premier corps de protection thermique sans amener le creuset en quartz en contact avec le premier corps de protection thermique. L'invention comprend en outre une plaque de redressement d'écoulement de gaz annulaire ayant un diamètre interne plus grand que le diamètre externe du premier corps de protection thermique. La plaque de redressement d'écoulement de gaz est au moins apte à se déplacer verticalement entre la même hauteur que l'extrémité inférieure du premier corps de protection thermique et l'extrémité inférieure du second corps de protection thermique. Cette configuration permet d'obtenir un appareil de tirage de monocristal qui est capable de minimiser la contamination par le carbone du monocristal de silicium qui est tiré.
PCT/JP2018/036992 2017-11-14 2018-10-03 Appareil de tirage de monocristal et procédé de tirage de monocristal de silicium WO2019097875A1 (fr)

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JP2017-219109 2017-11-14

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116288708A (zh) * 2023-03-20 2023-06-23 鸿新新能源科技(云南)有限公司 一种单晶硅生产装置及生产方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0789789A (ja) * 1993-09-20 1995-04-04 Fujitsu Ltd Ｓｉ結晶、結晶成長方法および結晶成長装置
JPH09328393A (ja) * 1996-05-31 1997-12-22 Ibiden Co Ltd シリコン単結晶引き上げ装置用の保温筒
JPH10158091A (ja) * 1996-11-22 1998-06-16 Shin Etsu Handotai Co Ltd 単結晶の製造装置および製造方法
KR20160068240A (ko) * 2014-12-05 2016-06-15 주식회사 엘지실트론 잉곳 성장장치

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0789789A (ja) * 1993-09-20 1995-04-04 Fujitsu Ltd Ｓｉ結晶、結晶成長方法および結晶成長装置
JPH09328393A (ja) * 1996-05-31 1997-12-22 Ibiden Co Ltd シリコン単結晶引き上げ装置用の保温筒
JPH10158091A (ja) * 1996-11-22 1998-06-16 Shin Etsu Handotai Co Ltd 単結晶の製造装置および製造方法
KR20160068240A (ko) * 2014-12-05 2016-06-15 주식회사 엘지실트론 잉곳 성장장치

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116288708A (zh) * 2023-03-20 2023-06-23 鸿新新能源科技(云南)有限公司 一种单晶硅生产装置及生产方法
CN116288708B (zh) * 2023-03-20 2023-08-11 鸿新新能源科技(云南)有限公司 一种单晶硅生产装置及生产方法

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