TW202426713A - Device, method and control system for crystal growth - Google Patents

Abstract

This application provides a device, a method and a control system for crystal growth. The device for crystal growth comprises: a furnace body; a crucible located in the furnace body for carry a silicon melt; a pulling device on the top of the furnace body for pulling the crystal from the silicon melt; a water-cooling heat shield surrounding the crystal and having an absorption surface for absorbing thermal radiation from the crystal surface, wherein the water-cooling heat shield is used to decrease temperature of local area of the crystal surface and increase vertical temperature gradient of the crystal; a thermal insulator located between the crystal and the water-cooling heat shield for shielding the water-cooling heat shield to reduce the area of the absorption surface; lifting devices respectively connecting to and adjusting the water-cooling heat shield and the thermal insulator to make the exposed absorption surface match with the local area of the crystal surface. The device for crystal growth is able to finely regulate vertical temperature gradient of the crystal.

Description

A crystal growth device, method and control system

The present invention relates to the field of crystal growth, and more particularly to a crystal growth device, method and control system.

At present, the main method for preparing large-sized single-crystal silicon is the Czochralski method, which is to melt polycrystalline silicon in a crucible, immerse the seed crystal in the liquid surface of the silicon melt, and slowly pull the seed crystal to grow a silicon single crystal with the same crystallization direction as the seed crystal. In the process of preparing large-sized silicon single crystals, the point defects of semiconductor silicon crystals are closely related to the temperature change of the crystal. By changing the time that the crystal rod is in a certain temperature range, the formation of point defects inside the crystal rod can be reduced. According to Vornkov's crystal growth theory, the defect type inside the crystal is related to the V/G value. V is the pulling speed of the crystal (mm/min), and G is the vertical temperature gradient of the solid-liquid interface of the crystal (K/mm). In industrial production, in order to increase output and ensure the quality of the crystal rod, it is hoped to adopt the highest possible pulling speed, and a higher pulling speed requires a larger temperature gradient.

In order to obtain a better cooling temperature gradient for the crystal rod during the growth of semiconductor silicon crystals, a water-cooled heat shield is usually set up in the hot field. The water-cooled heat shield consists of an inner heat shield ring, an outer heat shield ring, a middle cooling water channel, a water inlet channel, and a water outlet channel. Cooling water flows in the water-cooled heat shield, which can take away a large amount of heat. The cooled part can be cooled quickly, and the cooled area of the crystal rod will have a larger cooling temperature gradient, which increases the cooling rate of the crystal in this area and inhibits the nucleation and growth of defects. However, the size of the existing water-cooled heat shield is fixed, and the size of the area that can be cooled is also fixed. Therefore, the range of the temperature gradient that can be adjusted by the water-cooled heat shield during the crystal growth process is limited, and the heat taken away by the water-cooled heat shield cannot be flexibly adjusted. Existing water-cooled heat shields and crystal growth devices cannot precisely and flexibly adjust the temperature gradient of the crystal ingot to meet the requirements for manufacturing high-end silicon wafers.

Therefore, it is necessary to provide a crystal growth device, method and control system to at least partially solve the above problems.

A series of simplified concepts are introduced in the invention content section, which will be further described in detail in the specific implementation method section. The invention content section of the present invention does not mean to attempt to limit the key features and essential technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

In view of the shortcomings of the related art, the present invention provides a crystal growth device comprising: a furnace; a crucible, arranged inside the furnace, for accommodating a silicon melt; a pulling device, arranged at the top of the furnace, for pulling a crystal out of the silicon melt; a water-cooled heat shield, arranged around the crystal and having an absorbing surface for absorbing the thermal radiation of the crystal, the water-cooled heat shield is used to reduce the temperature of a local area of the crystal and increase the longitudinal temperature gradient of the crystal; a heat insulation cylinder, The heat-insulating cylinder is arranged between the crystal and the water-cooled heat shield, and is used to shield the water-cooled heat shield to reduce the area of the absorption surface; the lifting device is arranged at the top of the furnace body and is respectively connected to the water-cooled heat shield and the heat-insulating cylinder, and the lifting device is used to respectively adjust the height of the water-cooled heat shield and the heat-insulating cylinder and the height difference between the water-cooled heat shield and the heat-insulating cylinder, so that the position and area size of the absorption surface correspond to the local area of the crystal.

For example, when the height difference increases, the area of the absorption surface increases, and the thermal radiation of the crystal absorbed by the water-cooled heat shield increases; when the height difference decreases, the area of the absorption surface decreases, and the thermal radiation of the crystal absorbed by the water-cooled heat shield decreases.

For example, the heat-insulating cylinder may completely shield the water-cooled heat shield, or may not completely shield the water-cooled heat shield.

For example, the heat-insulating cylinder includes an inner layer, an outer layer, and a middle layer disposed between the inner layer and the outer layer.

For example, the material of the inner layer and the outer layer is set to be graphite material.

Illustratively, the material of the middle layer includes carbon fiber felt.

A crystal growth method comprises: obtaining a current longitudinal temperature gradient of a crystal; calculating a deviation between the current longitudinal temperature gradient of the crystal and a preset longitudinal temperature gradient; determining the position of a local area of the crystal that needs to be cooled based on the deviation of the longitudinal temperature gradient; and adjusting the height of a water-cooled heat shield and an insulation tube and the height difference between the water-cooled heat shield and the insulation tube based on the determined position of the local area of the crystal that needs to be cooled, so that the position and area size of the cooling surface of the water-cooled heat shield correspond to the local area of the crystal.

A crystal growth control system includes a processor, a memory, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the crystal growth method as described above is implemented.

The crystal growth device, method and control system provided by the present invention adjust the relative position of the heat insulation cylinder and the water-cooled heat shield, and adjust the absorption area of the water-cooled heat shield to absorb the thermal radiation of the crystal, so as to correspond to the position and size of the local area of the crystal that needs to be cooled, thereby adjusting the heat taken away by the water-cooled heat shield in a larger range, thereby adjusting the longitudinal temperature gradient of the crystal. The crystal growth device, method and control system provided by the present invention can suppress the nucleation and growth of crystal defects according to the production process, and the thermal history activity space is large, so that the water-cooled heat shield can play a more precise and flexible role.

In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, some technical features known in the art are not described in order to avoid confusion with the present invention.

It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the disclosure will be thorough and complete and will fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same figure numbers throughout represent the same elements.

It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and/or portions, these elements, components, regions, layers, and/or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatially related terms such as "under", "below", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "a", "an", and "said/the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and/or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and/or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and/or groups. When used herein, the term "and/or" includes any and all combinations of the relevant listed items.

Embodiments of the invention are described herein with reference to cross-sectional views which are schematic diagrams of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes shown due to, for example, manufacturing techniques and/or tolerances are to be expected. Accordingly, embodiments of the invention should not be limited to the particular shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an implanted region shown as a rectangle typically has rounded or curved features and/or an implant concentration gradient at its edges rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Accordingly, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the actual shape of the regions of the device and are not intended to limit the scope of the invention.

In order to thoroughly understand the present invention, a detailed structure will be proposed in the following description to explain the technical solution proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention can also have other implementation methods.

At present, the main method for preparing large-size single crystal silicon is the pulling method, that is, melting polycrystalline silicon into silicon melt in a crucible, immersing a seed crystal in the liquid surface of the silicon melt, and slowly pulling the seed crystal to grow a silicon single crystal with the same crystallization direction as the seed crystal.

According to relevant research, the point defects of semiconductor silicon crystals are closely related to the temperature change of the crystal. By changing the time that the crystal rod is in a certain temperature range, the formation of point defects inside the crystal rod can be reduced. In industrial production, in order to increase production, while ensuring quality, it is hoped to use the largest possible pulling speed. According to Vornkov's crystal growth theory, the defect type inside the crystal is related to the V/G value, where V is the pulling speed of the crystal (mm/min) and G is the vertical temperature gradient of the solid-liquid interface of the crystal (K/mm). A higher pulling speed requires a larger temperature gradient. Therefore, how to reasonably increase the temperature gradient of the crystal rod has always been an important research topic.

In order to obtain a better crystal rod cooling temperature gradient during the growth process of semiconductor silicon crystals, a water-cooled heat shield is usually set in the hot field. As shown in FIG1 , in the hot field of the crystal growth device 100, the guide tube 130 is set directly above the hot field for heat preservation and to prevent a large amount of heat loss. At the same time, in order to ensure that the crystal can have a better temperature gradient and speed up the cooling speed, a water-cooled heat shield 170 is set around the crystal inside the guide tube. The water-cooled heat shield 170 can take away a large amount of heat from the crystal rod. The water-cooled heat shield consists of an inner heat shield ring, an outer heat shield ring, a middle cooling water channel, a water inlet channel, and a water outlet channel. There is cooling water flowing in the water-cooled heat screen, which can take away a large amount of heat. The cooled area of the crystal rod will have a large cooling temperature gradient. The cooled part can cool down quickly, thereby increasing the temperature gradient in the upper part of the heat field, increasing the cooling rate of the crystal in this area, and inhibiting the formation and growth of defects.

In the related technology, the grown single crystal silicon can obtain a certain temperature gradient under the cooling of the water-cooled heat screen, but the heat absorbed by the water-cooled heat screen cannot be continuously adjusted. The cooling water in the water-cooled heat screen directly takes away a large amount of heat radiated from the surface of the crystal rod. The entire inner surface of the water-cooled heat screen is absorbing heat. The water-cooled heat screen is driven up and down by the lifting device. Since the closer the crystal rod is to the liquid surface, the higher the temperature, the water-cooled heat screens at different heights after lifting receive different amounts of heat due to the different surface temperatures of the crystal rod. In this way, the heat taken away by the water-cooled heat screen can only be roughly adjusted. Therefore, the above-mentioned water-cooled heat screen and crystal growth device cannot meet the needs of preparing high-end silicon wafers.

The present invention considers heat transfer by arranging a heat-insulating tube between the crystal rod and the water-cooled heat shield, and adjusts the heat dissipation of the corresponding position on the surface of the crystal rod through the heat-insulating tube to meet the preset temperature gradient. In this way, the formation and growth of defects can be suppressed when the pulling speed is increased, thereby ensuring the quality of the crystal rod.

In order to more precisely adjust the temperature gradient of the crystal rod, a heat-insulating cylinder that can be raised and lowered is set between the water-cooled heat shield and the crystal rod. The heat-insulating cylinder is between the crystal rod and the water-cooled heat shield, and can isolate at least part of the surface of the crystal rod from direct thermal radiation to the water-cooled heat shield. After the water-cooled heat shield is shielded by the heat-insulating cylinder, the thermal radiation directly received by the crystal rod will be directly reduced, and the amount of heat that can be taken away will also be reduced. By adjusting the position of the heat-insulating cylinder, the size of the absorption surface area of the water-cooled heat shield that absorbs the thermal radiation of the crystal rod is adjusted to continuously adjust the amount of heat taken away by the water-cooled heat shield, thereby forming a controllable temperature gradient on the crystal rod. Under the condition that the parameter requirements of large silicon wafers are getting higher and higher, it is necessary to adjust the temperature gradient of the crystal rod more precisely. Therefore, it is very necessary to design a structure with an adjustable area size of the absorption surface of the water-cooled heat shield.

The crystal growth device according to an embodiment of the present invention will be described in detail below with reference to Fig. 2. Fig. 2 is a schematic structural diagram of the crystal growth device according to an embodiment of the present invention.

As shown in FIG. 2 , the crystal growth device 200 provided by the present invention is a crystal growth device 200 for growing silicon single crystals using the Czochralski method. The crystal growth device 200 includes a furnace 201; a crucible 210, which is arranged inside the furnace 201 and is used to accommodate a silicon melt 203; a pulling device 250, which is arranged at the top of the furnace 201 and is used to pull a crystal 202 out of the silicon melt 203; a water-cooled heat shield 270, which is arranged around the crystal 202 and has an absorbing surface for absorbing the thermal radiation of the crystal 202, and the water-cooled heat shield 270 is used to reduce the temperature of a local area of the crystal 202 and increase the longitudinal temperature gradient of the crystal 202; an insulating cylinder 211, which is arranged between the crystal 202 and the water-cooled heat shield 270, and the insulating cylinder 211 is used to shield the crystal 202 from the heat radiation of the crystal 202. A water-cooled heat shield 270 is provided to reduce the area of the absorption surface, wherein the surface of the water-cooled heat shield 270 includes a portion blocked by the isolation tube and an unblocked portion, wherein the unblocked portion is the absorption surface of the water-cooled heat shield 170; a lifting device 280 is arranged at the top of the furnace body 201 and is respectively connected to the water-cooled heat shield 270 and the insulation tube 211, and the lifting device 280 is used to respectively adjust the height of the water-cooled heat shield 270 and the height of the insulation tube 211 as well as the height difference between the water-cooled heat shield 270 and the insulation tube 211, so that the position and area size of the absorption surface correspond to the local area of the crystal 202. 2 , when the height difference increases, the area of the absorption surface increases, and the thermal radiation of the crystal 202 absorbed by the water-cooled heat shield 270 increases; when the height difference decreases, the area of the absorption surface decreases, and the thermal radiation of the crystal 202 absorbed by the water-cooled heat shield 270 decreases.

In one embodiment, a crucible is used to contain polycrystalline silicon raw materials, and the polycrystalline silicon raw materials are used to grow single crystal silicon. The crucible includes a quartz crucible and a graphite crucible. The polycrystalline silicon raw materials are located in the quartz crucible, and the quartz crucible is located in the graphite crucible.

2 , the heater 220 may be a graphite heater, which is located in the furnace body 201 and is used to heat the crucible 210 , so that the polycrystalline silicon raw material in the crucible 210 becomes a melt 203 and maintains the melted state, wherein the heater 220 is disposed on the outer side of the crucible 210 .

Continuing with reference to FIG. 2 , the guide tube 230 (also called a heat shield) is located in the furnace body 201 and above the liquid surface of the melt 203 in the crucible 210, surrounding the growth area of the crystal 202. It is usually an inverted cone-shaped shield made of graphite material, which is used to adjust the flow direction and flow rate of the argon gas, so that the downwardly blown argon gas is concentrated near the growth interface of the crystal 202, and to prevent the high-temperature liquid surface and the crucible 210 from transmitting heat radiation to the cooling crystal 202, thereby increasing the heat output from the surface of the crystal 202 to the surrounding area, and increasing the heat transfer rate of the crystal and the temperature gradient of the crystal.

Continuing to refer to FIG. 2 , the vacuum pump 290 is connected to the bottom of the furnace body 201 and is used to continuously pump gas from the inside to the outside of the furnace body 201 to maintain the stability of the vacuum degree in the furnace body 201 and keep the negative pressure in the furnace body 201. During the growth process of the crystal 202, the decompression technology is adopted to keep the inert gas from top to bottom through the guide tube 230 throughout the entire furnace body 201, and the silicon oxide and impurity volatiles generated by the high temperature are promptly pumped away by the vacuum pump 290 to maintain the stability of the vacuum degree of the furnace body 201, reduce the influence of external factors on the vacuum degree in the furnace body 201, and ensure the quality of the crystal 202.

Continuing to refer to FIG. 2 , the insulation layer 240 may be carbon felt, which is located inside the furnace body 201 and between the heater 220 and the furnace body 201 to maintain the temperature inside the furnace.

Continuing with reference to FIG. 2 , the lifting device 250 (also referred to as the lifting head) is fixedly connected to the furnace body 201 , and may include a fast motor, a slow motor, a rotating motor, a steel cable, a seed crystal weighing head and other components, which are used to lift and rotate the seed crystal and record data such as the weight and displacement of the crystal 202 .

Continuing to refer to FIG. 2 , the crucible lifting unit 260 is fixedly connected to the furnace body 201 , and may include components such as a ball linear guide rail, a high-precision screw rod, a lifting motor, and a rotating motor, and is used to drive the crucible 210 to lift and rotate.

In one embodiment, the pulling device includes a vertically arranged seed crystal shaft, and the crucible lifting unit includes a vertically arranged crucible shaft. The seed crystal shaft is arranged above the crucible, and the crucible shaft is arranged at the bottom of the crucible. The seed crystal shaft is mounted with a seed crystal through a clamp at the bottom, and the top of the seed crystal shaft is connected to a seed crystal shaft driving device, so that it can be slowly pulled upward while rotating. Considering the length and stroke of the single crystal, the seed crystal shaft is made of a wire hinge. The bottom of the crucible shaft is provided with a crucible shaft driving device, so that the crucible shaft can drive the crucible to rotate.

When the crystal growth device 200 is working, silicon material is first put into the crucible 210, and then the heater 220 melts the silicon material into silicon melt 203 through the crucible 210. The seed crystal is immersed in the liquid surface of the silicon melt 203, and the pulling device 250 slowly pulls the seed crystal, thereby growing the crystal 202. As the pulling device 250 is pulled, the crystal 202 is separated from the unshielded portion and the shielded portion of the cylinder 210 by the water-cooled heat shield 270, wherein the unshielded portion (i.e., the absorption surface) increases the cooling rate near the solid-liquid interface of the crystal 202, suppresses the nucleation process of defects, and reduces the nucleation of defects in the crystal 202; the shielded portion reduces the cooling rate of the crystal 202 in this portion, which is beneficial for the defects in the crystal 202 to maintain a certain shape without other changes; the obtained crystal defects are within the required characteristic line width, so that the prepared silicon wafers meet the requirements of the high-end chip manufacturing industry.

In other embodiments, the heat-insulating cylinder may completely block the water-cooled heat shield, or may not block the water-cooled heat shield at all, and the specific adjustment may be made according to the process requirements.

In other embodiments, those skilled in the art may adjust the size and relative position of the water-cooled heat shield and the isolation cylinder according to different thermal fields and processes to increase the adjustment range of the longitudinal temperature gradient of the crystal.

In the embodiment of the present invention, a heat-insulating cylinder that can be raised and lowered is provided between the water-cooled heat shield and the crystal, and the heat-insulating cylinder is provided between the crystal and the water-cooled heat shield, so that the heat radiation of the crystal directly to the water-cooled heat shield can be isolated. After the water-cooled heat shield is shielded by the heat-insulating cylinder, the heat radiation directly received by the crystal will be directly reduced, and the amount of heat that can be taken away will also be reduced. Therefore, by adjusting the height of the heat-insulating cylinder, the size of the shielded part and the unshielded part (i.e., the absorption surface) can be adjusted, and then the area size of the absorption surface of the water-cooled heat shield can be adjusted, and the amount of heat taken away by the water-cooled heat shield can be directly adjusted to change the longitudinal temperature gradient of the crystal.

In one embodiment, the heat-insulating cylinder is composed of a three-layer structure, including an inner layer, an outer layer, and a middle layer disposed between the inner layer and the outer layer, wherein the inner layer and the outer layer are processed from high-purity graphite material, and the middle layer is processed from carbon fiber felt, or other heat-insulating foamed porous materials (such as glass fiber, asbestos, rock wool, and soft felt). The heat-insulating cylinder with a three-layer structure can better isolate the water-cooled heat shield and the thermal radiation between the crystals.

The crystal growth device, method and control system provided by the present invention adjust the relative position of the heat insulation cylinder and the water-cooled heat shield, and adjust the absorption area of the water-cooled heat shield to absorb the thermal radiation of the crystal, so as to correspond to the position and size of the local area of the crystal that needs to be cooled, thereby adjusting the heat taken away by the water-cooled heat shield in a larger range, thereby adjusting the longitudinal temperature gradient of the crystal. The crystal growth device, method and control system provided by the present invention can suppress the nucleation and growth of crystal defects according to the production process, and the thermal history activity space is large, so that the water-cooled heat shield can play a more precise and flexible role.

Referring to FIG. 3 , the present invention also provides a crystal growth method, which can be based on the crystal growth device as described above, and includes the following steps: S1: obtaining the current longitudinal temperature gradient of the crystal; S2: calculating the deviation between the current longitudinal temperature gradient of the crystal and the preset longitudinal temperature gradient; S3: determining the position of the local area of the crystal that needs to be cooled based on the deviation of the longitudinal temperature gradient; S4: based on the determined position of the local area of the crystal that needs to be cooled, adjusting the height of the water-cooled heat shield and the insulation cylinder and the height difference between the water-cooled heat shield and the insulation cylinder, so that the position and area size of the cooling surface of the water-cooled heat shield correspond to the local area of the crystal; wherein the height difference refers to the vertical distance between the lower end of the insulation cylinder and the lower end of the water-cooled heat shield.

FIG4 is a schematic diagram showing the structure of a crystal growth control system 400 according to an embodiment of the present invention. The crystal growth control system 400 includes a memory 410 and a processor 420.

The memory 410 stores program codes for implementing corresponding steps in the crystal growth method of the above-mentioned embodiment.

The processor 420 is used to run the program code stored in the memory 410 to implement the corresponding steps in the crystal growth method of the above embodiment.

The present invention also provides a computer-readable storage medium, on which program instructions are stored, and when the program instructions are run by a computer or a processor, they are used to execute the corresponding steps of the crystal diameter control method of the above embodiment. The storage medium may include, for example, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a read-only memory compact disc (CD-ROM), a USB memory device, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are exemplary only and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by a person of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as claimed in the appended claims.

It will be appreciated by those skilled in the art that the units and algorithm steps of the various examples described in the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

Similarly, it should be understood that in order to simplify the present invention and assist in understanding one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than those explicitly recited in each claim. More precisely, as reflected in the corresponding claim, the invention lies in that the corresponding technical problem can be solved with fewer features than all the features of a single disclosed embodiment. Therefore, the claims that follow a specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

It will be understood by those skilled in the art that all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or apparatus disclosed in this specification (including the accompanying claims, abstracts and drawings) may be combined in any combination, except where the features are mutually exclusive. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

It should be noted that the above-described embodiments illustrate rather than limit the present invention, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbols between parentheses should not be construed as limiting the claims. The present invention may be implemented with the aid of hardware comprising a number of different elements and with the aid of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

100: Crystal growth device 130: Flow guide tube 170: Water-cooled heat shield 200: Crystal growth device 201: Furnace 202: Crystal 203: Melt 210: Crucible 220: Heater 230: Flow guide tube 240: Insulation layer 250: Lifting device 260: Crucible lifting unit 270: Water-cooled heat shield 280: Lifting device 290: Vacuum pump 211: Insulation tube S1, S2, S3, S4: Steps 400: Crystal growth control system 410: Memory 420: Processor

FIG1 is a schematic diagram of a crystal growth apparatus.

FIG. 2 is a schematic diagram of a crystal growth device provided in an embodiment of the present invention.

FIG3 is a flow chart of a crystal growth method provided in an embodiment of the present invention.

FIG4 is a schematic diagram of a crystal growth control system provided by an embodiment of the present invention.

200: Crystal growth device

201: Furnace body

202: Crystal

203: Melt

210: Crucible

220: Heater

230: Guide tube

240: Insulation layer

250: Lifting device

260: Crucible lifting unit

270: Water-cooled heat shield

280: Lifting device

290: Vacuum pump

211: Insulation tube

Claims (8)

A crystal growth device, comprising: a furnace; a crucible, arranged inside the furnace, for containing silicon melt; a pulling device, arranged at the top of the furnace, for pulling out the crystal from the silicon melt; a water-cooled heat shield, arranged around the crystal and having an absorbing surface for absorbing the thermal radiation of the crystal, the water-cooled heat shield being used to reduce the temperature of the local area of the crystal and increase the longitudinal temperature gradient of the crystal; an insulating cylinder, arranged between the crystal and the water-cooled heat shield, the insulating cylinder being used to shield the water-cooled heat shield to reduce the area of the absorbing surface; A lifting device is arranged at the top of the furnace body and is respectively connected to the water-cooled heat shield and the insulation tube. The lifting device is used to respectively adjust the height of the water-cooled heat shield and the insulation tube and the height difference between the water-cooled heat shield and the insulation tube, so that the position and area size of the absorption surface correspond to the local area of the crystal. The crystal growth device as described in claim 1, wherein, when the height difference increases, the area of the absorption surface increases, and the thermal radiation of the crystal absorbed by the water-cooled heat shield increases; when the height difference decreases, the area of the absorption surface decreases, and the thermal radiation of the crystal absorbed by the water-cooled heat shield decreases. A crystal growth device as described in claim 1, wherein the thermal insulation tube may completely cover the water-cooled heat shield or may not completely cover the water-cooled heat shield. A crystal growth device as described in claim 1, wherein the thermal insulation tube includes an inner layer, an outer layer, and a middle layer arranged between the inner layer and the outer layer. A crystal growth device as described in claim 4, wherein the material of the inner layer and the outer layer is set to graphite material. A crystal growth device as described in claim 4, wherein the material of the middle layer includes carbon fiber felt. A crystal growth method, comprising: Obtaining the current longitudinal temperature gradient of the crystal; Calculating the deviation between the current longitudinal temperature gradient of the crystal and the preset longitudinal temperature gradient; Determining the position of the local area of the crystal that needs to be cooled based on the deviation of the longitudinal temperature gradient; Based on the determined position of the local area of the crystal that needs to be cooled, adjusting the height of the water-cooled heat shield and the insulation tube and the height difference between the water-cooled heat shield and the insulation tube, so that the position and area size of the cooling surface of the water-cooled heat shield correspond to the local area of the crystal. A crystal growth control system includes a processor, a memory, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the crystal growth method as described in claim 7 is implemented.