Heating device of single crystal furnace and single crystal furnace

Abstract

The utility model provides a heating device of a single crystal furnace, which comprises a crucible (1) used for being arranged in a furnace body of the single crystal furnace; the heater (5) surrounds the crucible (1), the heater (5) is arranged corresponding to the shape of the outer side of the crucible (1), the inner side of the heater (5) and the outer side of the crucible (1) are arranged at an interval, and an electrode (4) is arranged at the bottom of the heater (5); the driving mechanism comprises a supporting rod (2) and a driving element (3), the two ends of the supporting rod (2) are connected with the bottom of the crucible (1) and the driving element (3) respectively, and the driving element (3) is used for driving the supporting rod (2) to axially rotate; and the heater (5), the crucible (1) and the support rod (2) are coaxially arranged. The heating device of the single crystal furnace is high in material melting efficiency, and produced silicon rods are low in oxygen content. In addition, the utility model also provides a single crystal furnace.

Description

Technical Field

[0001] The present disclosure relates to a semiconductor manufacturing device, and particularly to a heating device for a single crystal furnace. Further, the present disclosure also relates to a single crystal furnace. Background Art

[0002] With the continuous development of the world economy, the demand for efficient energy in modernization construction is increasing. As a kind of green energy and a main energy source for the sustainable development of mankind, photovoltaic power generation has received increasing attention from countries around the world and has been vigorously developed. As a basic material for photovoltaic power generation, single crystal silicon wafers have a wide market demand. Currently, silicon wafers are mainly N-type. Due to the stricter control of oxygen content for N-type silicon wafers than for P-type silicon wafers and the requirement of low cost for crystal pulling in the market competition, it is of great significance to improve the melting efficiency of the single crystal furnace and reduce the oxygen content.

[0003] The heating device of the existing single crystal furnace often consists of an upper main heater and a bottom heater. This design results in high temperatures of the silicon melt at the upper and lower parts of the crucible, while the temperature in the middle is relatively low, affecting the melting efficiency of the single crystal furnace. And this design leads to an increase in the longitudinal temperature gradient of the silicon melt and enhanced thermal convection, resulting in an increase in the oxygen content during the production of single crystal silicon rods. Further, in the existing technology, the heater is set to be the same as the outer surface of the crucible and the heater wraps the crucible, thereby reducing the longitudinal temperature gradient of the silicon melt and further reducing the thermal convection. However, since the heater wraps the crucible, the thermal field of the heater and the position of the crucible cannot be optimally matched, resulting in low melting efficiency, higher energy consumption. And since the heater wraps the crucible, the heater is in direct contact with the crucible, resulting in a lower service life of the heater, increasing the maintenance pressure and production cost of the single crystal furnace. In addition, since the heater wraps the crucible, it is inconvenient to install the heater.

[0004] In view of this, it is necessary to design a heating device for a single crystal furnace that can overcome the above technical problems and effectively solve or alleviate the above technical defects. Summary of the Utility Model

[0005] One technical problem to be solved by the present disclosure is: to provide a heating device for a single crystal furnace, which has a relatively high melting efficiency and a relatively low oxygen content of the silicon rod produced.

[0006] Another technical problem to be solved by the present disclosure is: to provide a single crystal furnace, which has a relatively high melting efficiency and a relatively low oxygen content of the silicon rod produced.

[0007] To solve the above technical problems, an embodiment of the present disclosure provides a heating device for a single crystal furnace, which includes:

[0008] A crucible for being arranged in the furnace body of the single crystal furnace;

[0009] A heater, which surrounds the crucible. The shape of the inner side of the heater conforms to the outer shape of the crucible, and there is a gap between the inner side of the heater and the outer side of the crucible. Electrodes are provided at the bottom of the heater;

[0010] A driving mechanism, which includes a supporting rod and a driving element. The two ends of the supporting rod are respectively connected to the bottom of the crucible and the driving element, and the driving element is used to drive the supporting rod to rotate axially;

[0011] Among them, the heater, the crucible and the supporting rod are coaxially arranged.

[0012] In some embodiments, the heater is formed by surrounding with a number of "U"-shaped heating strips connected in sequence.

[0013] In some embodiments, the heater is an integral structure.

[0014] In some embodiments, it further includes a supporting base and a number of mounting feet. The supporting base is used to be arranged in the furnace body, and the heater is mounted on the supporting base through the mounting feet.

[0015] In some embodiments, the heater is formed with a clearance structure to form a clearance area for setting the mounting feet.

[0016] In some embodiments, the heater is formed with four clearance structures in a "cross" symmetry.

[0017] In some embodiments, the driving element includes a telescopic driving cylinder and a rotational driving cylinder. The telescopic driving cylinder is used to drive the crucible to move axially, and the rotational driving cylinder is used to drive the crucible to rotate around its axis.

[0018] In some embodiments, it further includes a crucible side for supporting the crucible and a crucible support for supporting the crucible and the crucible side. The crucible side covers the crucible, and the crucible support is arranged at one end of the supporting rod close to the crucible.

[0019] In some embodiments, it further includes a water-cooled screen and a flow guide cylinder. The water-cooled screen is arranged on the upper side of the crucible, the flow guide cylinder is arranged in the water-cooled screen, and one end opening of the flow guide cylinder is arranged corresponding to the opening of the crucible.

[0020] Based on the technical solution of the heating device of the above single crystal furnace, the embodiments of the present disclosure further provide a single crystal furnace, which includes the heating device of the single crystal furnace disclosed in any one of the above.

[0021] Through the above technical solution, the heating device of the single crystal furnace provided by the present disclosure enables the heater to surround the crucible. An electrode is provided at the bottom of the heater, and the heater can be electrically connected to an external power supply through the electrode. After being energized, the heater generates heat energy to heat the crucible and the silicon material inside the crucible. The driving mechanism can drive the crucible to rotate relative to the heater when the heater is heating, improving the heating uniformity. Moreover, the heater of the present disclosure is arranged in a shape following the outer side of the crucible. Therefore, compared with the prior art that uses an upper main heater and a bottom heater, there are problems such as higher temperatures of the silicon liquid at the upper and bottom parts of the crucible and relatively lower temperature in the middle, which affects the material melting efficiency of the single crystal furnace, and the longitudinal temperature gradient of the silicon liquid increases, the thermal convection intensifies, resulting in an increase in the oxygen content during the production process of the single crystal rod. The heater of the present disclosure with a shape following the outer side of the crucible can heat the crucible evenly. On the one hand, it improves the material melting efficiency, is conducive to increasing the daily charging amount of the single crystal furnace, and reduces the manufacturing cost. On the other hand, it eliminates the longitudinal temperature gradient and thermal convection of the silicon liquid, shortening the reaction time between the silicon material and the crucible, thereby effectively reducing the oxygen content of the silicon rod and improving the quality of the silicon rod. In addition, compared with the prior art where the heater wraps the crucible, the heater contacts the crucible and rotates with the crucible, resulting in a shorter service life of the heater. In the present disclosure, the inner side of the heater is spaced from the outer side of the crucible, the heater does not contact the crucible, and the heater does not rotate with the crucible when the crucible rotates, so the service life is longer, and thus the production cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 is a side view of the heater disclosed in the embodiment of the present disclosure;

[0024] Figure 2 is a perspective view of the heater disclosed in the embodiment of the present disclosure;

[0025] Figure 3 is a schematic structural diagram of the assembled heater and mounting foot plate disclosed in the embodiment of the present disclosure;

[0026] Figure 4 is a schematic structural diagram of the heating device of the single crystal furnace disclosed in the embodiment of the present disclosure.

[0027] Description of the reference numerals:

[0028] 1. Crucible; 2. Support rod; 3. Driving element; 4. Electrode; 5. Heater; 501. "U"-shaped heating strip; 502. Clearance structure; 6. Support base; 7. Mounting foot plate; 8. Clearance area; 9. Crucible wall; 10. Crucible support; 11. Water-cooled screen; 12. Flow guide cylinder. Detailed implementation manners

[0029] The following further describes in detail the implementation manners of the present disclosure in conjunction with the drawings and embodiments. The detailed description of the following embodiments and the drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms, not limited to the specific embodiments disclosed in the text, but including all technical solutions falling within the scope of the claims.

[0030] These embodiments are provided by the present disclosure to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, the components of materials, numerical expressions and values described in these embodiments should be interpreted as merely exemplary, rather than as limitations.

[0031] It should be noted that in the description of the present disclosure, unless otherwise specified, the meaning of "a plurality" is greater than or equal to two; the orientation or positional relationships indicated by terms such as "upper", "lower", "inner", "outer", etc. are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present disclosure. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0032] In addition, words such as "including" or "comprising" mean that the elements before this word are covered by the elements listed after this word, and do not exclude the possibility of also covering other elements.

[0033] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific situations. When it is described that a specific device is located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0034] All terms used in this disclosure have the same meanings as those understood by those of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as those, should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such herein.

[0035] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification.

[0036] As Figure 4 shown, the heating device of the single crystal furnace of the present disclosure includes: a crucible 1, a driving mechanism, an electrode 4, and a heater 5. The crucible 1 is used to be arranged inside the furnace body of the single crystal furnace. The heater 5 surrounds the crucible 1. The electrode 4 is arranged at the bottom of the heater 5. The electrode 4 is electrically connected to the heater 5 and an external power source respectively. When the heater 5 is energized, it generates heat energy to heat the crucible 1 and the silicon material inside the crucible 1. The heater 5 can be, but is not limited to, made of graphite, titanium alloy, or nickel-chromium alloy. The outer shape of the heater 5 corresponding to the crucible 1 is set in a conformal manner. As Figure 4 shown, the conformal heater 5 in this embodiment includes a first section arranged vertically and a second section bent inward in an arc shape. The first section can uniformly heat the side wall of the crucible 1, and the second section can uniformly heat the bottom of the crucible 1, so that the silicon material in the crucible 1 is heated more uniformly, improving the melting efficiency of the single crystal furnace. At the same time, it reduces the longitudinal temperature gradient of the silicon liquid, weakens the thermal convection, shortens the reaction time between the crucible 1 and the silicon material, and reduces the oxygen content of the produced silicon rod. The driving mechanism includes a support rod 2 and a driving element. Both ends of the support rod 2 are respectively connected to the bottom of the crucible 1 and the driving element 3. The heater 5, the crucible 1, and the support rod 2 are coaxially arranged. On the one hand, the support rod 2 can provide support for the crucible 1. On the other hand, the support rod 2 can drive the crucible 1 to rotate under the drive of the driving element 3. When the heater 5 heats the crucible 1 and the silicon material inside the crucible, the driving element 3 is controlled to drive the support rod 2 to rotate axially, and the support rod 2 drives the crucible 1 to rotate axially, thereby further improving the heating uniformity. The driving element 3 includes, but is not limited to, a motor, a hydraulic cylinder, and a pneumatic cylinder.

[0037] In some embodiments, as Figures 1 to 3 shown, the heater 5 of the present disclosure is formed by enclosing a plurality of sequentially connected "U"-shaped heating strips 501. The "U"-shaped heating strips 501 have relatively high heating uniformity, and the lower part of the "U"-shaped heating strips 501 in this embodiment is bent inward in an arc shape, so that the "U"-shaped heating strips 501 extend to the bottom of the crucible 1 to heat the bottom of the crucible 1, further improving the heating uniformity.

[0038] In some embodiments, as Figures 1 to 3As shown, the heater 5 of the present disclosure is an integral structure and is relatively easy to install.

[0039] In some embodiments, as Figure 3 shown, the heating device of the single crystal furnace in this embodiment further includes a support base 6 and a plurality of mounting feet 7. The mounting feet 7 in this embodiment are "L"-shaped feet. The short side of the "L"-shaped foot is connected to the support base 6, and the long side of the "L"-shaped foot is connected to the heater 5 to support the heater 5. A groove for installing the electrode 4 is formed on the support base 6. Under the support of the mounting feet 7, the heater 5 is electrically connected to the electrode 4.

[0040] In some embodiments, as Figure 2 and Figure 3 shown, the heater 5 is formed with a clearance structure 502 to form a clearance area 8 for setting the mounting feet 7, so as to facilitate the installation of the mounting feet 7.

[0041] In some embodiments, as Figure 3 shown, the heater 5 is formed with four clearance structures 502 in a "cross" symmetry, thereby forming four clearance areas in a "cross" symmetry. One mounting foot 7 is arranged in each clearance area. The mounting feet 7 in this embodiment are relatively convenient to install and have relatively stable support. The number of the clearance structures 502 and the mounting feet 7 can be adjusted according to the actual support stability requirements.

[0042] In some embodiments, as Figure 4 shown, the driving element 3 includes a rotation driving cylinder for driving the crucible 1 to rotate around its axis. By rotating the crucible 1, the silicon material is heated more evenly, further improving the melting efficiency of the single crystal furnace and the quality of the produced silicon rod. The driving element in this embodiment further includes a telescopic driving cylinder for driving the crucible 1 to move along its axis. By controlling the crucible 1 to move along its axis, the relative position between the crucible 1 and the heater 5 is changed. Thus, by controlling the telescopic driving cylinder, the crucible 1 can be adjusted to move to the position that best matches the thermal field generated by the heater 5, further improving the melting efficiency of the single crystal furnace and reducing energy consumption at the same time.

[0043] In some embodiments, as Figure 4 shown, the heating device of the single crystal furnace in this embodiment further includes a crucible side 9 and a crucible support 10. The crucible side 9 wraps the crucible 1 to support the crucible 1 through the crucible side 9. The crucible support 10 is arranged at one end of the support rod 2 close to the crucible 1 to support the crucible side 9 and the crucible 1 through the crucible support 10, improving the support stability of the crucible 1.

[0044] In some embodiments, as Figure 4As shown, the heating device of the single crystal furnace in this embodiment further includes a water-cooled screen 11 and a flow guide cylinder 12. The water-cooled screen 11 is arranged on the upper side of the crucible 1, and the flow guide cylinder 12 is arranged in the water-cooled screen 11. One end opening of the flow guide cylinder 12 is arranged corresponding to the opening of the crucible 1. The water-cooled screen 11 provides cooling for the growth of the silicon rod, increases the temperature gradient, thereby improving the pulling speed. The flow guide cylinder can insulate the thermal field and guide the flow direction of the argon gas.

[0045] The present disclosure provides a preferred heating device for a single crystal furnace, such as Figures 1 to 4As shown, the heating device of the single crystal furnace in this embodiment includes a crucible 1, an electrode 4, a heater 5, a driving mechanism, a support base 6, a mounting foot plate 7, a crucible wall 9, a crucible support 10, a water-cooled screen 11, and a guiding cylinder 12. The crucible 1 is arranged inside the furnace body of the single crystal furnace. The heater 5 surrounds the crucible 1. The heater 5, the crucible 1, and the support rod 2 are coaxially arranged. The two ends of the support rod 2 are respectively connected to the bottom of the crucible 1 and the driving element 3. The driving element 3 includes a telescopic cylinder for driving the crucible 1 to move up and down and a rotating cylinder for driving the crucible 1 to rotate around the axis. The crucible wall 9 covers the crucible 1. The crucible support 10 is arranged at one end of the support rod 2 close to the crucible 1 to provide stable support for the crucible 1 through the crucible wall 9, the crucible support 10, and the support rod 2. The heater 5 is arranged in a shape conforming to the outer shape of the crucible 1. There is a gap between the inner side of the heater 5 and the outer side of the crucible 1. The support base 6 is arranged on the inner bottom edge of the furnace body. A groove for installing the electrode 4 is formed on the support base 6. The mounting foot plate 7 is an "L"-shaped foot plate. The two ends of the mounting foot plate 7 are respectively connected to the support base 6 and the heater 5, so that the mounting foot plate 7 and the support base 6 support the heater 5. In the state where the heater 5 is supported, the bottom of the heater 5 contacts the electrode 4. The heater 5 is an integral structure formed by enclosing a number of "U"-shaped heating strips 501. The "U"-shaped heating strips are graphite heating strips. The bottom of the "U"-shaped heating strip 501 is electrically connected to the electrode 4. The electrode 4 is electrically connected to an external power supply. Thus, in the energized state, the "U"-shaped heating strip 501 generates heat energy to heat the crucible 1 and the silicon material inside the crucible 1. The heater 5 is formed with four clearance structures 502 in a "cross" symmetry. The mounting foot plate 7 is arranged at the clearance structures 502, which is convenient for installation and occupies less space. The heater 5 of this embodiment that conforms to the outer shape of the crucible 1 has a side wall corresponding to the side wall of the crucible 1 and a bottom that is curved inward in an arc shape corresponding to the bottom surface of the crucible 1, so as to ensure that the heater 5 can heat the side wall and the bottom of the crucible 1 simultaneously, improve the heating uniformity, eliminate the longitudinal temperature gradient and thermal convection, shorten the reaction time between the silicon material and the crucible 1, and thus reduce the oxygen content of the silicon rod. There is a gap between the inner side of the heater 5 and the outer side of the crucible 1 in this embodiment. The heater 5 in this embodiment does not contact the crucible 1 and does not rotate with the crucible 1, thereby extending the service life of the heater 5 and reducing the maintenance pressure and production cost. The heating device of the single crystal furnace in this embodiment is provided with a telescopic cylinder and a rotating cylinder. By controlling the extension or retraction of the movable end of the telescopic cylinder, the lifting position of the crucible 1 can be adjusted, so that the thermal field of the crucible 1 and the heater 5 can be optimally matched, improving the melting efficiency of the material and reducing the energy consumption. By controlling the rotating cylinder, the crucible 1 rotates around the axis, further improving the heating uniformity.In addition, the water-cooled screen 11 of this embodiment is arranged on the upper side of the crucible 1. The water-cooled screen 11 can provide temperature reduction for the growth of the silicon rod, increase the temperature gradient, thereby improving the pulling speed. The flow guide cylinder 12 is arranged in the water-cooled screen 11, and one end opening of the flow guide cylinder 12 is arranged corresponding to the opening of the crucible 1. The flow guide cylinder 12 can insulate the thermal field inside the furnace body and guide the flow direction of the argon gas.

[0046] Based on the heating device of the single crystal furnace in the above technical solution of the present utility model, the present utility model further provides a single crystal furnace. This single crystal furnace includes the heating device of the single crystal furnace disclosed above. Thus, the material melting efficiency of this single crystal furnace is relatively high, and the oxygen content of the produced silicon rod is relatively low.

[0047] As can be seen from the above description, the advantages of the present disclosure generally lie in: First, the heater surrounds the crucible, and the shape of the heater corresponding to the outer side of the crucible is conformally arranged, with relatively high heating uniformity; Second, there is a gap between the inner side of the heater and the outer side of the crucible, extending the service life of the heater; Third, the heater is surrounded by several sequentially connected "U"-shaped heating bars, improving the heating uniformity of the heater; Fourth, the telescopic driving cylinder can drive the crucible to move along its axial direction, making the thermal field of the heater and the position of the crucible optimally matched, further improving the material melting efficiency and reducing energy consumption.

[0048] So far, the embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details well known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed here based on the above description.

[0049] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for the purpose of illustration and not for the purpose of limiting the scope of the present disclosure. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be equivalently replaced without departing from the scope and spirit of the present disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way.

Claims

1. A heating device for a single crystal furnace, characterized in that: include: A crucible (1), wherein the crucible (1) is used to be arranged in a furnace body of a single crystal furnace; a heater (5), the heater (5) surrounding the crucible (1), the heater (5) being arranged in accordance with the shape of the outer side of the crucible (1), the inner side of the heater (5) being arranged at a distance from the outer side of the crucible (1), and an electrode (4) being arranged at the bottom of the heater (5); and A driving mechanism, the driving mechanism comprising a supporting rod (2) and a driving element (3), the two ends of the supporting rod (2) being respectively connected to the bottom of the crucible (1) and the driving element (3), the driving element (3) being used to drive the supporting rod (2) to rotate axially; Wherein, the heater (5), the crucible (1) and the supporting rod (2) are coaxially arranged.

2. The heating device for a single crystal furnace according to claim 1, characterized in that: The heater (5) is formed by a plurality of "U"-shaped heating strips (501) connected in sequence.

3. The heating device for a single crystal furnace according to claim 2, characterized in that: The heater (5) is an integrated structure.

4. The heating device for a single crystal furnace according to claim 1, characterized in that: It also comprises a supporting base (6) and a plurality of mounting foot plates (7), wherein the supporting base (6) is used to be arranged in the furnace body, and the heater (5) is mounted on the supporting base (6) via the mounting foot plates (7).

5. The heating device for a single crystal furnace according to claim 4, characterized in that: The heater (5) is formed with a space-avoiding structure (502) to form a space-avoiding area (8) for arranging the mounting foot plate (7).

6. The heating device for a single crystal furnace according to claim 5, characterized in that: The heater (5) is symmetrically formed with four air-avoiding structures (502) in a "cross" shape.

7. The heating device for a single crystal furnace according to claim 1, characterized in that: The driving element (3) comprises a telescopic driving cylinder and a rotating driving cylinder, wherein the telescopic driving cylinder is used to drive the crucible (1) to move along its axial direction, and the rotating driving cylinder is used to drive the crucible (1) to rotate around its axial direction.

8. The heating device for a single crystal furnace according to claim 1, characterized in that: It also comprises a crucible side (9) for supporting the crucible (1) and a crucible support (10) for supporting the crucible (1) and the crucible side (9); the crucible side (9) covers the crucible (1); and the crucible support (10) is arranged at one end of the support rod (2) close to the crucible (1).

9. The heating device for a single crystal furnace according to claim 1, characterized in that: It also comprises a water-cooling screen (11) and a guide tube (12), wherein the water-cooling screen (11) is arranged on the upper side of the crucible (1), the guide tube (12) is arranged in the water-cooling screen (11), and an opening at one end of the guide tube (12) is arranged corresponding to an opening of the crucible (1).

10. A single crystal furnace, characterized in that: A heating device for a single crystal furnace comprising the heating device according to any one of claims 1 to 9.

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