Heater assembly and single crystal furnace

Abstract

A heater assembly and a single crystal furnace, the single crystal furnace including a furnace body, in which a crucible rotatable by a support shaft is provided, the heater assembly including a heating section covering the outer surface of the crucible, rotatable in synchronization with the crucible, and including a plurality of connection electrodes, and a conductive section provided on the support shaft, the conductive section including a plurality of annular conductive members connected in one-to-one correspondence to the connection electrodes, and external connection electrodes connected in one-to-one correspondence to the plurality of annular conductive members, the connection electrodes being rotatable along the annular conductive members.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from Chinese Patent Application No. 202210705520.7, filed in China on June 21, 2022, the entire contents of which are incorporated herein by reference. This application relates to the technical field of silicon product fabrication, and in particular to heater assemblies and single crystal furnaces. [Background technology]

[0002] The Czochralski method for producing single-crystal silicon is currently the most common method for producing single-crystal silicon. The hot zone system is one of the most important factors in the crystallization of silicon material. The temperature gradient distribution in the hot zone directly affects whether the single crystal can be pulled smoothly and whether the quality of the single crystal can be controlled. In particular, the growth process of single-crystal silicon material using a Czochralski method single-crystal furnace typically uses a graphite hot zone to control the growth temperature and gradient. Specifically, the process involves melting polycrystalline raw material under a low-vacuum, inert gas environment, contacting a seed crystal, and then rotating the melt to produce a single-crystal material. The heat source in this process is primarily a graphite heater. In conventional hot zone structures, the heater is typically a fixed heater located on the periphery of the crucible. The thermal energy generated by the heater radiates heat to the crucible and the silicon material inside. This heating method is indirect and has low heating efficiency. Summary of the Invention [Problem to be solved by the invention]

[0003] In order to solve the above problems, the present application provides a heater assembly and a single crystal furnace that solve the problem of low efficiency of the indirect heating method. [Means for solving the problem]

[0004] In order to achieve the above object, a technical aspect adopted in an embodiment of the present application is a heater assembly used in a single crystal furnace, the single crystal furnace including a furnace body, a crucible provided in the furnace body, a bottom of the crucible supported by a support structure, the support structure including a support shaft, the crucible being rotatable by the support shaft, the heater assembly including: a heating unit covering the outer surface of the crucible, the heating unit being rotatable in synchronization with the crucible and including a plurality of connection electrodes; a conductive portion provided on the support shaft, the conductive portion including a plurality of annular conductive members connected to the connection electrodes in a one-to-one correspondence, and external connection electrodes connected to the plurality of annular conductive members in a one-to-one correspondence, the connection electrodes being rotatable along the annular conductive members, and the external connection electrodes being connected to an external power source.

[0005] Optionally, the conductive portion includes a cylindrical case mounted around the support shaft, and the inner wall of the case has a plurality of annular protrusions spaced apart along its circumferential direction as the annular conductive members, and the outer wall of the case has the external connection electrodes connected in one-to-one correspondence to the annular protrusions.

[0006] Optionally, the case is made of an insulating material.

[0007] Optionally, the support structure includes a support tray supported on the bottom of the crucible, the support shaft supports the support tray on the side away from the crucible, and the connection electrode includes a first sub-electrode and a second sub-electrode, the first sub-electrode being connected to the heating portion, one end of the second sub-electrode being connected to the first sub-electrode, and the other end of the second sub-electrode being connected to the conductive portion via a conductor that passes through the support tray and is fixed to the support shaft.

[0008] Optionally, the conductor is provided at its end remote from the crucible with a connecting protrusion cooperating with the annular protrusion, the connecting protrusion being movable along the annular protrusion.

[0009] Optionally, the heating section includes a strip heating element distributed in an S-shape outside the crucible, at least two ends of which extend to the bottom of the crucible and are connected to corresponding first sub-electrodes.

[0010] Optionally, an insulating and heat-conducting layer is provided between the heating portion and the crucible.

[0011] Optionally, a heat insulating protective cover is provided on the side of the heating section that is farther from the crucible.

[0012] An embodiment of the present application further provides a single crystal furnace including the heater assembly described above. [Effects of the Invention]

[0013] A beneficial effect of the present invention is that the heating portion covers the outside of the crucible, so that the heat directly heats the crucible and the silicon material therein via thermal conduction, improving efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing the structure of a heater assembly in the related art. [Figure 2] FIG. 2 is a schematic diagram illustrating the structure of a heater assembly in an embodiment of the present application. [Figure 3] 1 is a schematic diagram showing the structure of a conductor in an example of the present application. [Figure 4] 3A and 3B are schematic diagrams illustrating the structure of a conductive portion in an example of the present application. [Figure 5] FIG. 2 is a schematic diagram showing the structure of a heating unit in an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0015] In order to clarify the objectives, technical aspects and advantages of the embodiments of the present application, the technical aspects of the embodiments of the present application will be clearly and completely described below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. Other embodiments obtained by those skilled in the art based on the described embodiments of the present application shall all fall within the scope of protection of the present application.

[0016] In the description of this application, it should be explained that the orientations and positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are orientations and positional relationships shown based on the drawings, and are merely for the purpose of simplifying the description and explanation of this application, and do not indicate or imply that the described devices or elements must have a specific orientation or be configured or operated in a specific orientation, and should not be understood as limiting this disclosure. Furthermore, terms such as "first," "second," and "third" are for descriptive purposes only, and should not be understood as indicating or implying relative importance.

[0017] 1, in the related art, a single crystal furnace includes a furnace body 5, a crucible is provided within the furnace body 5, and the crucible is supported by a support structure 2. A heater 11 is generally a fixed heater located on the outer periphery of the crucible (the crucible includes a quartz crucible and a graphite crucible 1 provided around the quartz crucible), and a certain distance is provided between the heater 11 and the crucible, and the heater 11 is connected to an external power source via an electrode 12 provided at the bottom of the furnace body. The thermal energy generated by the heater heats the crucible and the silicon material therein in the form of radiation, and this heating method is indirect heating, which has low heating efficiency. To solve this problem, this embodiment provides a heater assembly for use in a single crystal furnace. Referring to FIGS. 2 to 5, the single crystal furnace includes a furnace body 5, a crucible is provided in the furnace body 5, the bottom of the crucible is supported by a support structure 2, the support structure 2 includes a support shaft 21, and the crucible is rotatable by the support shaft 21. The heater assembly includes: a heating unit 101 covering the outer surface of the crucible, the heating unit 101 being rotatable in synchronization with the crucible and including a plurality of connection electrodes; The conductive portion 203 is provided on the support shaft 21 and includes a plurality of annular conductive members 2031 connected to the connection electrodes in a one-to-one correspondence, and external connection electrodes 2032 connected to the plurality of annular conductive members 2031 in a one-to-one correspondence, the connection electrodes being rotatable along the annular conductive members 2031, and the external connection electrodes 2032 being connected to an external power source.

[0018] In this embodiment, the heating element 101 covers the outer surface of the crucible, i.e., the heating element 101 is in direct contact with the crucible, so that the heat directly heats the crucible and the silicon material inside via thermal conduction, improving efficiency. However, in an actual process, the crucible must be rotated to ensure the crystal shape and convection control of the melt. Therefore, to ensure that the heating element 101 remains electrically conductive during the crucible rotation, this embodiment provides the conductive element 203. The conductive element 203 includes a plurality of annular conductive members 2031 connected to the connecting electrodes in a one-to-one correspondence and external connecting electrodes 2032 connected to the plurality of annular conductive members 2031 in a one-to-one correspondence. The plurality of connecting electrodes included in the heating element 101 can rotate along the annular conductive members 2031. That is, during the process in which the heating section 101 rotates synchronously with the crucible, the connection electrode rotates along the corresponding annular conductive member 2031, and the connection electrode is always in contact with the corresponding annular conductive member 2031, so that the external connection electrode 2032 connected to the corresponding annular conductive member 2031 ensures that the heating section 101 and the external power source are maintained in communication with each other.

[0019] In summary, the heater assembly of this embodiment solves the problem of power connection during the rotation of the heating section 101, and realizes a transition from the heat radiation of the conventional hot zone heating process to solid-to-solid heat conduction, greatly improving the thermal efficiency of the hot zone and the equipment and reducing heat loss. In addition, this hybrid structural design significantly saves space in the hot zone within the furnace body 5, which is advantageous for reducing the size of the equipment or increasing the material input capacity of the equipment (increasing the crucible volume).

[0020] It should be noted that the crucible includes a graphite crucible 1 and a quartz crucible 3 arranged around each other, and the heating part 101 covers the outside of the graphite crucible 1 .

[0021] Referring to Figure 4, in an exemplary embodiment, the conductive portion 203 includes a cylindrical case mounted around the support shaft 21, and the inner wall of the case is provided with a plurality of annular protrusions spaced apart along the circumferential direction as the annular conductive members 2031, and the outer wall of the case is provided with the external connection electrodes 2032 connected in one-to-one correspondence to the annular protrusions.

[0022] Illustratively, the case is made of an insulating material so as to avoid short circuits between adjacent annular conductive members 2031.

[0023] In an exemplary embodiment, the case is fixedly connected to the furnace body 5 .

[0024] In an exemplary embodiment, the support structure 2 includes a support tray supported on the bottom of the crucible, the support shaft 21 supports the side of the support tray away from the crucible, and the connection electrodes include a first sub-electrode and a second sub-electrode 201, the first sub-electrode is connected to the heating section 101, one end of the second sub-electrode 201 is connected to the first sub-electrode, and the other end of the second sub-electrode 201 is connected to the conductive section 203 via a conductor 202 fixed to the support shaft 21 through the support tray.

[0025] Dividing the connection electrode into the first sub-electrode and the second sub-electrode 201 provided separately is advantageous for assembling the crucible, the heating part 101, and the support structure 2 together.

[0026] Exemplarily, the second sub-electrode 201 is a bolt electrode, but is not limited thereto.

[0027] For example, the support tray includes a central region and an edge region surrounding the central region, the central region is recessed to form a groove, and the bottom of the crucible is a protrusion cooperating with the groove. The second sub-electrode 201 is provided in the edge region.

[0028] A bolt electrode is adopted as the second sub-electrode 201, and a bolt hole is provided in the edge region, passing through the edge region along the axial direction of the support shaft 21, and the bolt electrode is screwed into the bolt hole, with one end of the bolt electrode connected to the first sub-electrode and the other end connected to the conductive portion 203 via the conductor 202.

[0029] Referring to Figure 3, in an exemplary embodiment, the end of the conductor 202 remote from the crucible is provided with a connecting protrusion 2021 that cooperates with the annular protrusion, and the connecting protrusion 2021 is movable along the annular protrusion.

[0030] The conductor 202 is distributed on the outer surface of the support shaft 21 along the axial direction of the support shaft 21, and the conductor 202 may be a conductive wire, and an insulating protective cover is provided on the outside of the portion of the conductive wire exposed to the case.

[0031] Exemplarily, in the axial direction of the support shaft 21, the height of the connecting protrusion 2021 is smaller than the distance between two adjacent annular conductive members 2031 so as to avoid short circuiting.

[0032] For example, the conductor 202 is fixed to the support shaft 21 via an adhesive layer, and the connection protrusion 2021 is fixed to the support shaft 21 via an adhesive layer.

[0033] Referring to Figure 5, in an exemplary embodiment, the heating section 101 includes a strip heating element distributed in an S-shape outside the crucible, and at least two ends of the strip heating element extend to the bottom of the crucible and are connected to the corresponding first sub-electrodes.

[0034] For example, the heating units 101 have a strip-like structure and are vertically distributed outside the crucible. The vertically distributed heating units 101 can ensure thermal convection and heat distribution of the melt through the structural distribution and power control of the heating units 101, further optimizing the thermal gradient during the crystal growth process and more effectively controlling the quality and yield of crystal growth.

[0035] For example, the belt-shaped structure has a thickness of 2 to 3 cm in the radial direction of the crucible, but is not limited to this.

[0036] In an exemplary embodiment, an insulating and heat-conducting layer is provided between the heating portion 101 and the crucible, and may be made of a material such as graphite or ceramic.

[0037] The crucible is made of graphite material, and the wall thickness of the crucible is, but is not limited to, 1 to 2 cm.

[0038] In an exemplary embodiment, a heat insulating protective cover 102 is provided on the side of the heating unit 101 that is farther from the crucible. The heat insulating protective cover 102 can cover the entire heating unit 101, preventing oxides generated during the process from being deposited on the surface of the heating unit 101 and affecting the heating effect, while also preventing heat radiation from the heating unit 101 to the outside, thereby maintaining stable heating and reducing power consumption.

[0039] An embodiment of the present application further provides a single crystal furnace including the heater assembly described above.

[0040] The single crystal furnace includes a furnace body 5, in which a crucible (including a graphite crucible 1 and a quartz crucible 3) is provided, and the crucible contains a silicon melt 6, symbol 7 denotes a crystal rod, the exterior of the crucible is covered by a heating section 101, and the exterior of the heating section 101 is covered with an insulating protective cover 102, the support structure 2 is provided with a second sub-electrode 201 connected to the heating section 101, and the second sub-electrode 201 is connected to a conductive section 203 via a conductor 202, and a heat-insulating layer 4 is further provided on the inner part of the furnace body 5.

[0041] It is understood that the above embodiments are merely exemplary embodiments adopted to explain the principles of the present application, and the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and scope of the present application, and these modifications and improvements shall also fall within the scope of protection of the present application.

Claims

1. A heater assembly for use in a single crystal furnace, the single crystal furnace including a furnace body, a crucible provided in the furnace body, a bottom of the crucible supported by a support structure, the support structure including a support shaft, the crucible being rotatable by the support shaft, the heater assembly including: a heating unit covering the outer surface of the crucible, the heating unit being rotatable integrally with the crucible and including a plurality of connection electrodes; a conductive portion provided on the support shaft, the conductive portion including a plurality of annular conductive members connected to the connection electrodes in a one-to-one correspondence, and external connection electrodes connected to the plurality of annular conductive members in a one-to-one correspondence, the connection electrodes being rotatable along the annular conductive members, and the external connection electrodes being connected to an external power supply; the conductive portion includes a cylindrical case mounted around the support shaft, and a plurality of annular protrusions are provided on an inner wall of the case along a circumferential direction thereof at intervals as the annular conductive members, and the external connection electrodes are provided on an outer wall of the case in one-to-one correspondence with the annular protrusions, The support structure includes a support tray supported on the bottom of the crucible, the support shaft supports the support tray on the side away from the crucible, the connecting electrode includes a first sub-electrode and a second sub-electrode, the first sub-electrode is connected to the heating section, one end of the second sub-electrode is connected to the first sub-electrode, and the other end of the second sub-electrode is connected to the multiple annular conductive members of the conductive section via a conductor that passes through the support tray and is fixed to the support shaft, a heater assembly.

2. The heater assembly of claim 1 , wherein the case is made of an insulating material.

3. 2. The heater assembly of claim 1, wherein the end of the conductor remote from the crucible is provided with a connecting protrusion that cooperates with the annular protrusion, the connecting protrusion being movable along the annular protrusion.

4. 2. The heater assembly of claim 1, wherein the heating section includes a strip heating element distributed in an S-shape outside the crucible, and at least two ends of the strip heating element extend to the bottom of the crucible and are connected to corresponding first sub-electrodes.

5. The heater assembly of claim 1 , further comprising an insulating and heat-conducting layer provided between the heating portion and the crucible.

6. 2. The heater assembly according to claim 1, wherein a heat insulating protective cover is provided on a side of said heating section remote from said crucible.

7. A single crystal furnace comprising a heater assembly according to any one of claims 1 to 6.

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