CN114108073B - Growth method of large-diameter monocrystalline silicon - Google Patents

Growth method of large-diameter monocrystalline silicon Download PDF

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CN114108073B
CN114108073B CN202111450500.1A CN202111450500A CN114108073B CN 114108073 B CN114108073 B CN 114108073B CN 202111450500 A CN202111450500 A CN 202111450500A CN 114108073 B CN114108073 B CN 114108073B
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New Meguiar Suzhou Semiconductor Technology Co ltd
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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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

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Abstract

A growth method of large-diameter monocrystalline silicon belongs to monocrystallineSilicon preparation technology field. A method for growing large diameter single crystal silicon comprising: growing single crystal silicon by a Czochralski method, wherein the constant diameter phase of growing single crystal silicon comprises the following process conditions: argon is introduced; the silicon single crystal body and the crucible rotate in opposite directions, and the maximum cross-sectional area in the horizontal direction of the region where forced convection caused by the rotation of the silicon single crystal body is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein, M is 45 percent or less 1 /M 0 Less than 90%. The growth method of the monocrystalline silicon has higher monocrystalline success rate and the quality of the grown monocrystalline silicon is better.

Description

Growth method of large-diameter monocrystalline silicon
Technical Field
The application relates to the technical field of monocrystalline silicon preparation, in particular to a growth method of large-diameter monocrystalline silicon.
Background
The Czochralski method is the most commonly used method for growing single crystal silicon rods or ingots, and in practical production, in order to control the drawing of a relatively perfect crystal, a method for controlling the crystal growth rate V and the ratio of the temperature gradient G at the solid-liquid interface of the silicon rod and the silicon melt within a reasonable interval is generally adopted. With the continuous development of semiconductor fabrication processes, the demand for large-diameter and high-quality single crystal silicon is growing. There have been many efforts in the industry to improve the quality of single crystal silicon and the diameter of single crystal silicon: for example, by increasing the maximum width in the horizontal direction of forced convection due to rotation of the silicon single crystal, a silicon single crystal rod having a more uniform distribution of interstitial oxygen concentration and point defect density can be obtained. For example, the thermal field and the flow field can be optimized by a computer simulation method, the utilization rate of the thermal field is improved, and the like.
However, the inventors of the present application have found in the study that the above method no longer works when single crystal silicon having a diameter of not less than 300mm is grown. Even if V/G is controlled in a reasonable range, the success rate of single crystals in a crucible of the same diameter is continuously reduced with the increase of the diameter. This is because the larger the diameter of the grown single crystal silicon, the smaller the surface of the silicon melt in the crucible, and the closer the solid-liquid interface of the single crystal silicon growth is to the inner wall of the crucible, i.e., the larger the proportion of the single crystal area in the surface of the silicon melt. In order to prevent the success rate of single crystals from being excessively reduced due to the excessive proportion of the single crystal area in the surface of the silicon melt, large-diameter single crystal silicon can be grown by adopting a crucible with larger diameter, a single crystal growth furnace with larger diameter matched with the crucible, and other matched devices. But obviously, the production cost of the monocrystalline silicon rod is greatly increased, and the competitiveness of enterprises is reduced. Therefore, there is an urgent need to develop a process technique for growing large-diameter and high-quality single crystal silicon with high success rate in a crucible of limited size.
Disclosure of Invention
The invention provides a method for growing large-diameter monocrystalline silicon, which has high success rate of monocrystalline and good quality of the grown monocrystalline silicon.
In some embodiments, the large diameter single crystal silicon referred to herein means single crystal silicon having a diameter of not less than 300mm, alternatively 300 to 508mm.
In accordance with one aspect of the present invention, there is provided a method for growing large diameter single crystal silicon, comprising: growing single crystal silicon by a Czochralski method, wherein the constant diameter phase of growing single crystal silicon comprises the following process conditions: argon is introduced; the silicon single crystal body and the crucible rotate in opposite directions, and the maximum cross-sectional area in the horizontal direction of the region where forced convection caused by the rotation of the silicon single crystal body is dominant is M 1 The area of the whole silicon melt surface is M 0 (see FIG. 1), wherein 45% M 1 /M 0 ＜90％。
The horizontal maximum cross-sectional area of the region where forced convection is dominant due to rotation of the single crystal silicon body reflects the size of the forced convection unit due to rotation of the single crystal silicon body.
By controlling the size of the zone in the melt, i.e. M, in which forced convection is dominant by rotation of the monocrystalline silicon body 1 /M 0 Can realize the growth of large-diameter monocrystalline silicon with high success rate of monocrystalline in a crucible with limited size. Specifically, by utilizing the technical scheme of the invention, the monocrystalline silicon with the diameter of the monocrystalline silicon body at the constant diameter stage/the diameter of the crucible being more than or equal to 51%, optionally more than or equal to 56%, can be prepared with higher monocrystalline success rate. Not only can save energy consumption, but also reduces the production cost of the silicon single crystal and improves the competitiveness of enterprises.
The diameter of the monocrystalline silicon body refers to the average diameter of the monocrystalline silicon body grown in the equal diameter stage, and the diameter of the crucible refers to the diameter of the liquid level of the silicon melt after melting is completed. The whole silicon meltArea M of surface 0 Is the area of the horizontal cross section at the maximum diameter of the crucible.
Illustratively, the crucible is a quartz crucible.
In a preferred embodiment, the method is carried out by controlling the M to be 55 percent or less 1 /M 0 Less than or equal to 73 percent, thereby further improving the success rate of the monocrystal and ensuring that the appearance of the monocrystal silicon is not deformed during growth.
In an exemplary embodiment, M 1 The adjustment of the size can be controlled by adjusting the technological parameters such as the rotation speed of the monocrystalline silicon body, the rotation speed of the crucible, the argon flow and the like.
By way of example, M can be achieved by increasing the rotational speed of the monocrystalline silicon body, decreasing the rotational speed of the crucible, increasing the argon flow, etc 1 An increase in size; m can be realized by reducing the rotation speed of the monocrystalline silicon body, increasing the rotation speed of the crucible, reducing the argon flow and the like 1 And a reduction in size.
In one possible embodiment, the rotation speed of the monocrystalline silicon body may range from 6 to 8rpm, preferably from 6 to 7.5rpm. The rotation speed of the monocrystalline silicon body is controlled in a reasonable range, and the excessive rotation speed of the monocrystalline silicon body can cause deformation of the appearance of the crystal and even can not be used for successfully drawing the single crystal; when the rotation speed of the single crystal silicon body is too small, the quality of the single crystal silicon is lowered.
In one possible scenario, the rotational speed of the crucible may range from 0.5 to 3rpm. The rotating speed of the crucible is controlled within a reasonable range, if the rotating speed is too high, not only the oxygen entering the melt becomes more, but also the radial distribution of the interstitial oxygen concentration of the solid-liquid interface of the monocrystalline silicon becomes more uneven, so that the quality of the monocrystalline silicon is reduced.
In one possible scenario, the argon flow may range from 100 to 180lpm, preferably from 100 to 140lpm. The inventors of the present application found that although the argon flow rate had less effect on the convection cell, by using a larger flow rate of argon, a change in the convection cell could also be caused. Specifically, for growth of single crystal silicon with a growth diameter of not less than 300mm, when the argon flow rate is less than 100lpm, such as 80lpm, the flow rate of argon is small, which is insufficient to drive the change of forced convection caused by rotation of the single crystal silicon body; when the flow of the argon is further improved, for example, the flow is improved to be more than 100lpm, the forced convection caused by the rotation of the monocrystalline silicon body can be enhanced; however, this benefit of improvement gradually decreases with further increases in argon flow. Specifically, when the argon flow is lifted to more than 140lpm, the effect of the lifting of the argon flow on forced convection caused by rotation of monocrystalline silicon is not obvious, on the contrary, the surface of the silicon melt is easy to shake due to the fact that the argon flow is lifted to cause the argon flow to be faster, dislocation is easy to occur in the grown silicon single crystal, and the success rate of the single crystal is reduced.
It should be noted that the above numerical ranges of the rotation speed of the single crystal silicon, the rotation speed of the crucible, and the argon flow are only one preferred mode, and not limiting, and those skilled in the art can adjust the size of the forced convection unit caused by the actual rotation of the single crystal silicon body, that is, only the horizontal maximum cross-sectional area of the area where the forced convection is dominant due to the rotation of the single crystal silicon body is ensured, and the ratio of the area to the surface of the whole silicon melt is within the range proposed in the application, so that the technical effect of improving the growth success rate of the large-diameter single crystal silicon can be achieved. According to the technical scheme of the invention, the monocrystalline silicon which is not deformed can be pulled.
According to the invention, at least the following effects are achieved: the size of the forced convection unit caused by the rotation of the monocrystalline silicon body in the crucible is controlled, so that the adverse effect of factors which can cause poor growth of the monocrystalline silicon on the growth of the monocrystalline silicon near the inner wall of the crucible is reduced, and the success rate of growing the large-diameter monocrystalline in the crucible with limited size is improved. Further, by controlling the rotation speed of the monocrystalline silicon body, the rotation speed of the crucible and the argon flow, the size of the forced convection unit caused by the rotation of the monocrystalline silicon is ensured to meet the requirement, and meanwhile, the gap oxygen concentration and the point defect concentration are uniformly distributed.
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In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of the isodiametric stage of growing single crystal silicon in an embodiment of the present application.
Icon: 11-crucible; 12-single crystal silicon body.
Detailed Description
Embodiments of the present application will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustration of the present application and should not be construed as limiting the scope of the present application. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The Czochralski method is the most commonly used method for growing single crystal silicon rods or ingots, and in practical production, in order to control the drawing of a relatively perfect crystal, a method for controlling the crystal growth rate V and the ratio of the temperature gradient G at the solid-liquid interface of the silicon rod and the silicon melt within a reasonable interval is generally adopted. However, the inventors of the present application have found in the study that the above method no longer works when single crystal silicon having a diameter of not less than 300mm is grown using a crucible of the same size. Even if V/G is controlled in a reasonable range, the success rate of single crystals is continuously decreased with the increase of crystal diameter, see Table 1.
Table 1 does not control M 1 /M 0 Success rate of growing single crystal silicon with different diameters by crucible of same specification
Figure BDA0003385724000000051
The following is a specific description of a method for growing single crystal silicon according to an embodiment of the present application:
the embodiment of the application provides a growth method of large-diameter monocrystalline silicon, which comprises the following steps: growing single crystal silicon by a Czochralski method, wherein the constant diameter phase of growing single crystal silicon comprises the following process conditions:
argon is introduced;
the single crystal silicon body 12 and the crucible 11 rotate in opposite directions, the horizontal maximum cross-sectional area of the region where forced convection caused by the rotation of the single crystal silicon body 12 is M1, and the area of the entire silicon melt surface is M 0 (see FIG. 1), wherein 45% M 1 /M 0 ＜90％。
The method for growing monocrystalline silicon by the Czochralski method is a common method, and is generally that a monocrystalline silicon rod is pulled in a monocrystalline furnace, a crucible 11 containing raw materials such as polycrystalline silicon blocks is placed in a graphite crucible support above the crucible support, heating and melting are carried out in a protective atmosphere, after the process temperature is regulated and controlled, a seed crystal is inserted into molten polycrystalline silicon liquid through a guide cylinder, and is reversely rotated and lifted upwards with the crucible 11, so that the polycrystalline silicon liquid is crystallized and solidified into monocrystalline silicon according to the silicon atom arrangement sequence of the seed crystal, and then the monocrystalline silicon is subjected to the necking and shouldering stages, and the equal-diameter growth of the monocrystalline silicon is carried out.
It is generally considered that: when growing single crystal silicon by the Czochralski method, the flow inside the melt is mainly of three types: natural convection due to the temperature gradient, forced convection due to rotation of the crystal and rotation of the crucible 11, eddy currents formed by interaction of natural convection and forced convection, and the like.
The inventors of the present application have recognized a fact based on a large number of studies that there may be factors causing poor growth of single crystal silicon such as impurities in the vicinity of the inner wall of the crucible 11. When growing single crystal silicon of a larger diameter in the same size crucible 11, the solid-liquid interface due to the growth of single crystal silicon is closer to the inner wall of the crucible 11. At this time, if the maximum width of the forced convection unit in the horizontal direction due to the rotation of the single crystal silicon body 12 is too large, factors near the inner wall of the crucible 11 that cause the growth failure of the single crystal silicon are more likely to enter the forced convection unit due to the rotation of the single crystal silicon body 12 and then brought near the solid-liquid interface where the single crystal silicon grows, and the yield is greatly increased when the single crystal silicon grows.
The inventors of the present application have creatively found that, when growing larger-sized single crystal silicon in the same-sized crucible 11, at the constant diameter stage of growing single crystal silicon,by controlling the size of the forced convection unit caused by the rotation of the silicon single crystal body 12 in the crucible 11 to be within a reasonable range, the adverse effect of the adverse factor on the growth of silicon single crystal can be effectively suppressed, and further, it has been found that by controlling 45% or less of M 1 /M 0 Less than 90%, especially controlling the M to be 55% or less 1 /M 0 Less than 73 percent, the probability that the bad factors enter the vicinity of the interface of the growth of the monocrystalline silicon can be reduced, thereby reducing the influence of the bad factors on the growth of the monocrystalline silicon, further being capable of realizing the high-quality growth of the monocrystalline silicon with large diameter without replacing a growth device with larger diameter.
Specifically, by controlling M 1 /M 0 The single crystal silicon with the diameter of the single crystal silicon body 12 at the constant diameter stage and the diameter of the crucible 11 being more than or equal to 51%, optionally the diameter ratio being more than or equal to 56%, can be prepared with a higher single crystal success rate. Thereby enabling large-diameter single crystal silicon to be grown with a high single crystal success rate in the crucible 11 of a limited size. Not only can save energy consumption, but also can reduce the production cost of the silicon single crystal and improve the competitiveness of enterprises.
Illustratively, the diameter of the monocrystalline silicon body 12 at the constant diameter stage/the diameter of the crucible 11 is a value of any one or between any two of 51%, 52%, 53%, 55%, 56%, 58%, 60%, 62%, 65%, 67 and 68%.
Illustratively, the diameter of the single crystal silicon body 12 at the constant diameter stage may be any one of 12 inches, 13 inches, 14 inches, 15 inches, 16 inches, 17 inches, 18 inches, 19 inches, 20 inches, or a value between any two.
Illustratively, the crucible 11 may have a diameter of any one or a number between any two of 18 inches, 19 inches, 20 inches, 21 inches, 22 inches, 23 inches, 24 inches, 25 inches, 26 inches, 28 inches, 29 inches, 30 inches, 31 inches, 32 inches, 33 inches, 34 inches, 35 inches, 36 inches, 37 inches, 38 inches, 39 inches.
For example, silicon single crystal having a diameter of 14-19 inches may be grown using a crucible 11 having a diameter of 28 inches; for another example, silicon single crystal having a diameter of 16 to 20 inches may be grown using the 30 inch crucible 11.
Illustratively M 1 /M 0 Is a value of any one or between any two of 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% and 89%.
The method for growing monocrystalline silicon according to the embodiment of the application is particularly suitable for growing monocrystalline silicon rods with the diameter not smaller than 300mm in a mode that the diameter of the monocrystalline silicon body 12 at the constant diameter stage/the diameter of the crucible 11 is not smaller than 51%. Thereby, the energy consumption and the growth cost for the growth of the large-diameter monocrystalline silicon can be further reduced. Optionally the diameter of the single crystal silicon rod at the constant diameter stage is 300-508 mm.
Of course, it can be expected by those skilled in the art that the technical scheme of the application is not only suitable for single crystal silicon rod growth with the diameter of more than or equal to 300mm, but also suitable for single crystal silicon rod growth with the diameter of less than 300 mm.
In addition, the area M of the entire silicon melt surface 0 Can be measured directly. Maximum cross-sectional area M in the horizontal direction of the forced convection unit caused by rotation of the silicon single crystal body 12 1 The process parameters can be confirmed by model tests and simulation of the process parameters by CFD (Computational Fluid Dynamics ) simulation software. By inputting parameters such as the rotation speed of the corresponding monocrystalline silicon body 12, the rotation speed of the crucible 11, the argon flow, the heating power, the thermal field material and distribution, the furnace body material and structure and the like into CFD simulation software, the state of melt flow in the silicon melt can be obtained through simulation, and M can be obtained through simulation calculation 1 Is of a size of (a) and (b).
M 1 The adjustment of the size can be controlled by adjusting the technological parameters such as the rotation speed of the monocrystalline silicon body 12, the rotation speed of the crucible 11, the argon flow and the like.
By way of example, M may be achieved by increasing the rotational speed of the monocrystalline silicon body 12, decreasing the rotational speed of the crucible 11, increasing the argon flow, etc 1 An increase in size; m can be realized by reducing the rotation speed of the single crystal silicon body 12, increasing the rotation speed of the crucible 11, reducing the flow rate of argon gas, and the like 1 And a reduction in size.
In one possible embodiment, the rotation speed of the single crystal silicon body 12 is in the range of 6 to 8rpm, preferably 6 to 7.5rpm. It should be noted that, when growing single crystal silicon having a diameter of not less than 300mm, the rotation speed of the single crystal silicon body 12 is not preferably excessively large. This is because, on the one hand, excessive rotational speed of the silicon single crystal body 12 may cause an increase in the degree of turbulence inside the melt and a decrease in the stability of the melt flow; on the other hand, too large rotation speed can also impact the crystal, when the rotation speed of the monocrystalline silicon body 12 reaches 8rpm, the appearance of the monocrystalline silicon body 12 can slightly deform, and the success rate of the monocrystalline is reduced; when the rotation speed of the single crystal silicon body 12 reaches 9rpm, the shape of the single crystal silicon body 12 is severely deformed, a large number of dislocations are formed in the single crystal silicon body 12, and the wire breakage is caused, so that the single crystal cannot be successfully pulled.
The speed at which the single crystal silicon body 12 is rotated is not too low. When the rotation speed of the single crystal silicon body 12 is too small, for example, 4rpm or 5rpm, the centrifugal force generated by the rotation of the single crystal silicon body 12 is weak, the forced convection unit caused by the centrifugal force is small, the maximum cross section in the horizontal direction will not exceed the edge part of the solid-liquid interface of the single crystal silicon body 12, in this case, the oxygen-containing impurities dissolved into the melt from the crucible wall can cause the equilibrium concentration of the interstitial oxygen [ Oi ] between the central part and the edge part of the single crystal silicon body 12 to be more unstable, the radial distribution of the interstitial oxygen concentration near the solid-liquid interface of the single crystal silicon is more uneven, and the radial interstitial oxygen distribution of the finally grown single crystal silicon is also more uneven, namely, the quality of the single crystal silicon is reduced.
In one possible solution, the rotation speed of the crucible 11 ranges from 0.5 to 3rpm. The rotation speed of the crucible 11 can influence the balance of oxygen-containing impurities between the crucible wall and the silicon melt, and the larger the rotation speed is, the more oxygen-containing impurities enter the melt from the crucible wall, and the more oxygen content moves to a solid-liquid interface through convection; on the other hand, the rotation of the crucible 11 has a large influence on the flow and strength in the entire silicon melt, and the larger the rotation speed of the crucible 11, the more severe the flow of the silicon melt, the stronger the forced convection due to the rotation of the crucible 11, and the more the forced convection due to the rotation of the single crystal silicon body 12 is suppressed.
The rotation speed of the crucible 11 should be controlled within a reasonable range, if the rotation speed is too large, not only the oxygen entering the melt becomes more, but also the radial distribution of the interstitial oxygen concentration at the solid-liquid interface of the monocrystalline silicon becomes more uneven, thereby reducing the quality of the monocrystalline silicon.
In one possible embodiment, the argon flow is in the range of 100 to 180lpm, preferably 100 to 140lpm. The inventors of the present application found that although the argon flow rate had less effect on the convection cell, by using a larger flow rate of argon, a change in the convection cell could also be caused. Specifically, for growth of single crystal silicon having a growth diameter of not less than 300mm, when the argon flow rate is less than 100lpm, such as 80lpm, the change in forced convection due to the rotation of the single crystal silicon body 12 is insufficient due to the small argon flow rate; when the argon flow is further increased, for example, to be more than 100lpm, the forced convection caused by the rotation of the monocrystalline silicon body 12 can be enhanced; however, this benefit of improvement gradually decreases with further increases in argon flow. Specifically, when the argon flow is lifted to more than 140lpm, the effect of the lifting of the argon flow on forced convection caused by rotation of monocrystalline silicon is not obvious, on the contrary, the surface of the silicon melt is easy to shake due to the fact that the argon flow is lifted to cause the argon flow to be faster, dislocation is easy to occur in the grown silicon single crystal, and the success rate of the single crystal is reduced.
It should be noted that the parameters of the crystal rotation speed of 6-8 rpm, the crucible 11 rotation speed of 0.5-3rpm, and the argon flow rate of 100-180 lpm provided in the present application are only examples, and do not represent M in which each combination can achieve the requirements of the present invention 1 /M 0 Range. In some cases, certain combinations of parameters, in combination with certain crucible 11 and thermal field configurations, may result in M 1 /M 0 The technical effect of the present invention cannot be achieved in such a case, which does not meet the scope of the present invention as required.
In addition, even if the same crystal rotation speed, crucible 11 rotation speed, and argon flow rate are controlled, M may be caused by the difference in structure and material of the single crystal furnace 1 Is different in size. For the above case, the person skilled in the art can, based onIn the case of an actual single crystal furnace, according to the teachings of the present invention, the rotation speed of the silicon single crystal body 12, the rotation speed of the crucible 11, the argon flow rate, etc. are adjusted so as to make M 1 /M 0 Meets the requirements of the technical scheme of the application, and can realize the technical effect of improving the success probability of single crystals.
Illustratively, the argon gas flow is in a range of any one or between any two of 100lpm, 110lpm, 120lpm, 130lpm, 140lpm, 150lpm, 160lpm, 170lpm, and 180lpm.
Illustratively, the rotational speed of the monocrystalline silicon body 12 is in a range between any one or any two of 6rpm, 6.5rpm, 7rpm, 7.5rpm, and 8rpm.
Illustratively, the rotational speed of the crucible 11 is in a range between any one or any two of 0.5rpm, 1.0rpm, 1.5rpm, 2.0rpm, 2.5rpm, and 3.0 rpm.
The method for growing large-diameter single crystal silicon of the present application is described in further detail below with reference to examples.
Example 1
The present embodiment provides a method for growing large-diameter single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 8rpm, the rotation speed of the crucible 11 is 0.5rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 80%. The success rate of drawing a perfect single crystal by the growth method of single crystal silicon of this embodiment is 65%, and minute deformation occurs during crystal growth.
Example 2
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, and growing a single crystalArgon is introduced into the silicon at the constant diameter stage, and the flow rate of the argon is 120lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7.5rpm, the rotation speed of the crucible 11 is 0.5rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 73%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 88%, and the shape of the single crystal is not deformed.
Example 3
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 68%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 95%, and the shape of the single crystal is not deformed.
Example 4
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 6.5rpm, the rotation speed of the crucible 11 is 0.5rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 65%. Success rate of drawing perfect Single Crystal by the growth method of Single Crystal silicon of the embodimentAt 95%, no deformation of the single crystal morphology occurred.
Example 5
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 180lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 6.5rpm, the rotation speed of the crucible 11 is 0.5rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 68%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 87%, and the shape of the single crystal is not deformed.
Example 6
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 120lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 6rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 57%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 83%, and the shape of the single crystal is not deformed.
Example 7
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 100lpm; the silicon single crystal body 12 and the crucible 11 rotate in opposite directions, and the silicon single crystal body 12 rotates at a speed of6rpm, the rotation speed of the crucible 11 was 1rpm, and the horizontal maximum cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 was dominant was M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 55%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 82%, and the shape of the single crystal is not deformed.
Example 8
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 80lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 6rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 49%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 56%, and the shape of the single crystal is not deformed.
Example 9
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 5rpm, the rotation speed of the crucible 11 is 3rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 45%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 48%, and the shape of the single crystal is not deformed.
Example 10
The present embodiment provides a single crystal siliconA growth method of (2), comprising: growing a single crystal silicon rod with the diameter of 480mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 72%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 72%, and the shape of the single crystal is not deformed.
Example 11
The present embodiment provides a method for growing single crystal silicon, comprising: growing a monocrystalline silicon rod with the diameter of 465mm in a monocrystalline furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the monocrystalline furnace is 780mm, argon is introduced in the constant diameter stage of growing monocrystalline silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 60%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 80%, and the shape of the single crystal is not deformed.
Example 12
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The whole silicon is meltedThe surface area of the body is M 0 Wherein M is 1 /M 0 65%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 95%, and the shape of the single crystal is not deformed.
Example 13
The present embodiment provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 480mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 82%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 60%, and the shape of the single crystal is not deformed.
Example 14
The present embodiment provides a method for growing single crystal silicon, comprising: growing a monocrystalline silicon rod with the diameter of 465mm in a monocrystalline furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the monocrystalline furnace is 780mm, argon is introduced in the constant diameter stage of growing monocrystalline silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 76%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 64%, and the shape of the single crystal is not deformed.
Example 15
The present embodiment provides a method for growing single crystal silicon, comprising: growing a silicon single crystal rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, and the silicon single crystal rod is grownIntroducing argon gas into the constant diameter stage of the monocrystalline silicon, wherein the flow rate of the argon gas is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 7rpm, the rotation speed of the crucible 11 is 1rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 71%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the embodiment is 74%, and the shape of the single crystal is not deformed.
Comparative example 1
The present comparative example provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 150lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 9rpm, the rotation speed of the crucible 11 is 0.5rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 90%. Serious deformation occurs during crystal growth, and a single crystal silicon rod cannot be successfully pulled.
Comparative example 2
The present comparative example provides a method for growing single crystal silicon, comprising: growing a single crystal silicon rod with the diameter of 440mm in a single crystal furnace by a Czochralski method, wherein the inner diameter of a crucible 11 in the single crystal furnace is 780mm, argon is introduced in the constant diameter stage of growing single crystal silicon, and the flow rate of the argon is 140lpm; the silicon single crystal body 12 and the crucible 11 are rotated in opposite directions, the rotation speed of the silicon single crystal body 12 is 5rpm, the rotation speed of the crucible 11 is 5rpm, and the maximum horizontal cross-sectional area of the region where forced convection due to the rotation of the silicon single crystal body 12 is dominant is M 1 The area of the whole silicon melt surface is M 0 Wherein M is 1 /M 0 40%. The success rate of drawing a perfect single crystal by the growth method of the single crystal silicon of the comparative example is 38%, and the shape of the single crystal is not deformed.
The main process parameters and experimental results of examples 1 to 9 and comparative examples 1 to 2 are recorded in table 2, and the main process parameters and experimental results of examples 10 to 15 are recorded in table 3, wherein the single crystal success rate in this application refers to the number of times of tests/total number of times of tests that a single crystal silicon rod of a target diameter is pulled under the same process conditions without breakage.
TABLE 2 partial process parameters and single crystal success rate and single crystal deformation conditions of examples 1 to 9 and comparative examples
Figure BDA0003385724000000171
Analysis of results: as can be seen from the results of Table 2, when 45% M 1 /M 0 At < 90%, a higher single crystal success rate can be achieved even at a diameter of the single crystal silicon body/crucible diameter=56.4%. Controlling the M content to be 55 percent or less 1 /M 0 Less than or equal to 73 percent, the success rate of the monocrystal is further improved, and the appearance of the monocrystal does not deform during the growth of the monocrystal silicon.
TABLE 3 partial process parameters and monocrystalline success rates for examples 10-15
Figure BDA0003385724000000172
Figure BDA0003385724000000181
As can be seen from Table 3, by controlling M 1 /M 0 A success rate of single crystal of 60% can be achieved even if single crystal silicon of 480mm is grown with crystal diameter/crucible diameter=66.7%; the single crystal success rate can be further improved with smaller single crystal silicon body/crucible diameter ratios.
The foregoing is merely a specific embodiment of the present application and is not intended to limit the application, and various modifications and variations may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims (8)

1. A method for growing large-diameter single crystal silicon, comprising: growing single crystal silicon by a Czochralski method, wherein the constant diameter phase of growing single crystal silicon comprises the following process conditions:
argon is introduced;
the monocrystalline silicon body and the crucible rotate in opposite directions, the maximum cross-sectional area in the horizontal direction of the area where forced convection is dominant due to rotation of the monocrystalline silicon body is M1, and the area of the whole silicon melt surface is M0, wherein M1/M0 is more than or equal to 55% and less than or equal to 73%;
the diameter of the monocrystalline silicon body is not less than 300mm;
the diameter of the monocrystalline silicon body at the constant diameter stage/the diameter of the crucible is more than or equal to 51 percent.
2. The method for growing large-diameter single crystal silicon according to claim 1, wherein the rotation speed of the single crystal silicon body is 6 to 8rpm.
3. The method for growing large-diameter single crystal silicon according to claim 2, wherein the rotation speed of the single crystal silicon body is 6 to 7.5rpm.
4. The method for growing large-diameter single crystal silicon according to claim 1, wherein the rotation speed of the crucible is 0.5-3rpm.
5. The method for growing large-diameter silicon single crystal according to claim 1, wherein the flow rate of the argon gas is 100 to 180lpm.
6. The method for growing large-diameter silicon single crystal according to claim 5, wherein the flow rate of the argon gas is 100 to 140lpm.
7. The method for growing a large-diameter single crystal silicon according to claim 1, wherein the diameter of the single crystal silicon body is 300 to 508mm.
8. The method for growing a large-diameter single crystal silicon according to claim 1, wherein the diameter of the single crystal silicon body at the constant diameter stage/the diameter of the crucible is not less than 56%.
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