A method and device for stripping a wafer from a silicon carbide ingot

Abstract

The present invention discloses a method and device for stripping a wafer from a silicon carbide ingot, wherein the silicon carbide ingot includes a wafer layer to be stripped, a modified layer and a silicon carbide substrate, and the modified layer is located between the wafer layer and the silicon carbide substrate. The method for stripping a wafer from a silicon carbide ingot of the present invention comprises: injecting a pre-prepared liquid into the modified layer of the silicon carbide ingot by ultrasonic vibration, and after the liquid fills the modified layer, cooling the silicon carbide ingot filled with the liquid until the liquid freezes to cause the modified layer to expand and fracture, and the wafer layer is separated from the silicon carbide substrate, and then grinding the separated wafer layer to obtain a wafer. The present invention can reduce the material loss when the silicon carbide wafer is stripped, thereby effectively improving the utilization rate of the silicon carbide ingot, and the present invention can also improve processing efficiency and reduce manufacturing costs.

Description

Technical Field

[0001] The present invention relates to the field of silicon carbide wafer manufacturing, and in particular to a method and device for stripping a wafer from a silicon carbide ingot. Background Art

[0002] With the development of science and technology, chips have become an indispensable part of people's lives. For example, various electronic devices such as mobile phones and computers that we use in daily life cannot do without chips. Among them, the production process of chips mainly includes four parts: IC design, chip production, chip packaging and finished product testing.

[0003] As for the production of wafers, the cutting method is currently mostly used. Specifically, the ingot is cut into thin pieces using a slicing saw, and then the front and back of the obtained wafer are ground to finally obtain the wafer. However, when using this method to produce wafers, a large part of the material of the ingot will be lost, resulting in a very low utilization rate of the ingot. Summary of the invention

[0004] To this end, the present invention provides a method and apparatus for stripping a wafer from a silicon carbide ingot, in an effort to solve or at least alleviate the above problems.

[0005] According to one aspect of the present invention, a method for stripping a wafer from a silicon carbide ingot is provided, wherein the silicon carbide ingot comprises a wafer layer to be stripped, a modified layer and a silicon carbide substrate, the modified layer being located between the wafer layer and the silicon carbide substrate, the method comprising: injecting a pre-prepared liquid into the modified layer of the silicon carbide ingot by ultrasonic vibration; after the liquid fills the modified layer, cooling the silicon carbide ingot filled with the liquid until the liquid freezes to cause the modified layer to expand and fracture, thereby separating the wafer layer from the silicon carbide substrate; and grinding the separated wafer layer to obtain a wafer.

[0006] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, the liquid is water or an aqueous solution containing a substance capable of reducing the tension of water as a solute.

[0007] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, a liquid is stored in a container, and accordingly, a pre-prepared liquid is injected into the modified layer of the silicon carbide ingot by ultrasonic vibration, comprising: vibrating the liquid in the container by an ultrasonic vibration device; placing the silicon carbide ingot into the liquid in a direction in which the grooves of its modified layer are perpendicular to the surface of the liquid.

[0008] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, the silicon carbide ingot is placed in a liquid in a direction in which the grooves of its modified layer are perpendicular to the liquid surface, including: placing the silicon carbide ingot in the liquid in the above direction at a predetermined rate.

[0009] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, the silicon carbide ingot filled with liquid is cooled, including: rotating the silicon carbide ingot filled with liquid so that its surface is parallel to the surface of the liquid; and translating the rotated silicon carbide ingot from the liquid to an environment with a temperature below zero degrees for standing.

[0010] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, grinding the separated wafer layer includes: grinding and removing the silicon carbide substrate and the modified layer portion remaining on the surface of the separated wafer layer.

[0011] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, formation of a modified layer includes: positioning a focal point of a pulsed laser beam of a wavelength that is transparent to the silicon carbide ingot at a predetermined distance from a surface of the silicon carbide ingot, the predetermined distance being the thickness of the wafer to be stripped; and irradiating the silicon carbide ingot with pulsed laser beams to form a modified layer.

[0012] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, the silicon carbide ingot is placed in a liquid with the grooves of its modified layer perpendicular to the surface of the liquid, including: placing the silicon carbide ingot in the liquid in the above direction by a clamping and lifting device.

[0013] Optionally, in the method for stripping a wafer from a silicon carbide ingot according to the present invention, when the silicon carbide ingot filled with liquid is cooled, the silicon carbide ingot filled with liquid is rotated by a grabbing and flipping transfer device, and the rotated silicon carbide ingot is translated from the liquid to an environment with a temperature below zero degrees for standing.

[0014] According to another aspect of the present invention, there is provided a device for stripping a wafer from a silicon carbide ingot, wherein the silicon carbide ingot comprises a wafer layer to be stripped, a modified layer and a silicon carbide substrate, wherein the modified layer is located between the wafer layer and the silicon carbide substrate, and the device comprises: a container for storing a pre-prepared liquid; an ultrasonic vibration device for vibrating the liquid in the container; a clamping and lifting device for placing the silicon carbide ingot in the vibrating liquid; a grabbing, flipping and transferring device for transferring the silicon carbide ingot filled with liquid to a cooling device after the liquid fills the modified layer of the silicon carbide ingot; a cooling device for cooling the silicon carbide ingot filled with liquid so that the modified layer expands and breaks due to freezing of the liquid therein, thereby separating the wafer layer from the silicon carbide substrate; and a grinding device for grinding the separated wafer layer to obtain a wafer.

[0015] Optionally, in the device for stripping a wafer from a silicon carbide ingot according to the present invention, the clamping and lifting device places the silicon carbide ingot into the vibrating liquid with the grooves of the modified layer thereof being perpendicular to the surface of the liquid.

[0016] Optionally, in the device for stripping a wafer from a silicon carbide ingot according to the present invention, the clamping and lifting device places the silicon carbide ingot into the vibrating liquid in the above direction at a predetermined speed.

[0017] Optionally, in the device for stripping wafers from a silicon carbide ingot according to the present invention, a grabbing, flipping and transferring device rotates the silicon carbide ingot filled with liquid so that its surface is parallel to the surface of the liquid, and translates the rotated silicon carbide ingot from the liquid to a cooling device.

[0018] The present invention can reduce material loss during silicon carbide wafer peeling, thereby effectively improving the utilization rate of silicon carbide ingots, and the present invention can also improve processing efficiency and reduce manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To achieve the above and related purposes, certain illustrative aspects are described herein in conjunction with the following description and accompanying drawings, which indicate various ways in which the principles disclosed herein can be practiced, and all aspects and their equivalents are intended to fall within the scope of the claimed subject matter. The above and other purposes, features and advantages of the present disclosure will become more apparent by reading the following detailed description in conjunction with the accompanying drawings. Throughout the present disclosure, the same reference numerals generally refer to the same parts or elements.

[0020] Figure 1 A flow chart of a method 100 for stripping a wafer from a silicon carbide ingot according to an embodiment of the present invention is shown;

[0021] Figure 2 shows a side view of a silicon carbide ingot according to one embodiment of the present invention;

[0022] Figure 3 A schematic diagram showing the injection of liquid into a modified layer of a silicon carbide ingot according to an embodiment of the present invention is shown;

[0023] Figure 4 A schematic structural diagram of an apparatus for peeling a wafer from a silicon carbide ingot according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0025] Silicon carbide (SiC) wafers are currently the most advanced third-generation semiconductor materials in the world. Semiconductor devices manufactured with silicon carbide wafers as substrates have the advantages of high power, high voltage resistance, high temperature resistance, high frequency, low energy consumption, and strong radiation resistance. As for silicon carbide wafers, most of them are currently obtained by longitudinal cutting with diamond saw blades or diamond wires. However, the hardness of silicon carbide is extremely high, which causes slicing to take a long time, and a large amount of material will be lost during the slicing process, resulting in a very small number of wafers that can be produced from a single ingot. Based on this, the present invention provides a method for stripping wafers from a silicon carbide ingot, which can effectively improve the utilization rate of the silicon carbide ingot and reduce the manufacturing cost of silicon carbide wafers.

[0026] Figure 1 A flow chart of a method 100 for stripping a wafer from a silicon carbide ingot according to an embodiment of the present invention is shown. In this embodiment, a modified layer may be formed inside the silicon carbide ingot using a laser, and the silicon carbide ingot may be divided into a wafer layer to be stripped, a modified layer, and a silicon carbide substrate, and then stripping may be performed.

[0027] According to one embodiment of the present invention, a modified layer can be formed in the following manner. First, a focal point of a pulsed laser beam of a wavelength that is transparent to a silicon carbide ingot is positioned at a predetermined distance from a surface of the silicon carbide ingot. Then, the silicon carbide ingot is irradiated with pulsed laser beams to form a modified layer. The predetermined distance is the thickness of the wafer to be peeled off, and the surface on which the positioning is based is the upper surface or the lower surface of the silicon carbide ingot. Specifically, when the wafers are peeled off from top to bottom, the surface is the upper surface of the silicon carbide ingot, and when the wafers are peeled off from bottom to top, the surface is the lower surface of the silicon carbide ingot.

[0028] By forming a modified layer inside the silicon carbide ingot, the silicon carbide ingot can be divided into three parts with the modified layer as the middle layer, wherein the part of the upper and lower parts with a thickness equal to the thickness of the wafer to be peeled off is the wafer layer to be peeled off, and the other part is the silicon carbide substrate. As an example, the focal point of the pulsed laser light is positioned at a position equal to the thickness of the wafer to be peeled off from the upper surface of the silicon carbide ingot, and the pulsed laser light is irradiated to form the modified layer, then Figure 2 As shown, the upper, middle and lower parts are respectively the wafer layer 1 to be peeled off, the modified layer 2 and the silicon carbide substrate 3.

[0029] At this point, the silicon carbide ingot is divided into three parts: the wafer layer to be peeled off, the modified layer and the silicon carbide substrate (that is, the silicon carbide ingot includes the wafer layer to be peeled off, the modified layer and the silicon carbide substrate), and the modified layer is located between the wafer layer to be peeled off and the silicon carbide substrate. Next, a method for peeling a wafer from the silicon carbide ingot is described.

[0030] like Figure 1As shown, the method 100 for stripping a wafer from a silicon carbide ingot of the present invention starts at 110. In 110, a pre-prepared liquid is injected into the modified layer of the silicon carbide ingot by ultrasonic vibration. The liquid may be water, and in some embodiments, may also be an aqueous solution with a substance capable of reducing water tension as a solute, that is, a certain amount of a substance capable of reducing water tension, such as alcohol, soap, etc., is added to water, and the present invention is not limited to this.

[0031] According to one embodiment of the present invention, the use of ultrasonic vibration to inject the pre-prepared liquid into the modified layer can be specifically achieved in the following manner.

[0032] First, the prepared liquid is placed in a container. The container may be a rectangular container, or other types of containers, such as a cylindrical container, etc., which is not limited by the present invention. Then, the liquid in the container is vibrated by an ultrasonic vibration device. Specifically, several ultrasonic vibrators (see Figure 4 ) to vibrate the liquid in the container. Finally, place the silicon carbide ingot in the liquid (i.e., the container). In order to allow the gas in the modified layer to be discharged smoothly so that the prepared liquid can be injected into the modified layer, the silicon carbide ingot can be placed in the liquid in a direction in which the grooves of its modified layer are perpendicular to the surface of the liquid. Furthermore, in order to facilitate the discharge of the gas, the silicon carbide ingot can be slowly placed in the liquid in the above-mentioned direction at a predetermined rate. The predetermined rate can specifically be the rate of liquid immersion (i.e., the predetermined rate is equivalent to the speed of solution immersion). Of course, this is only an example, and the present invention is not limited to this. In a specific embodiment, those skilled in the art can set it according to actual needs.

[0033] In addition, when placing the silicon carbide ingot into the liquid, the above-mentioned can be achieved by a clamping and lifting device, specifically, as Figure 3 By means of the clamping and lifting device 4, the silicon carbide ingot 5 is lifted at a predetermined speed so that the grooves of the modified layer are perpendicular to the surface of the liquid 6 (e.g. Figure 3 The liquid 6 in the container 7 will keep vibrating under the action of the ultrasonic vibration device 8, so the silicon carbide ingot 5 is placed in the liquid 6, and the liquid 6 can be injected into the modified layer (i.e., the gap) between the wafer layer to be peeled off and the silicon carbide substrate.

[0034] Regarding the duration of ultrasonic vibration, it should be explained here that the duration of ultrasonic vibration generally fluctuates between 5 minutes and 30 minutes depending on the size of the wafer area, the modification process, and the state of the solution. That is, the duration of ultrasonic vibration is generally between 5 minutes and 30 minutes (for wafers below 8 inches), which is specifically determined by the area of ​​the wafer layer, the process of the modified layer, and the state of the liquid.

[0035] After the liquid fills the modified layer, enter 120 to cool the silicon carbide ingot filled with liquid until the liquid freezes to cause the modified layer to expand and break, and the wafer layer is separated from the silicon carbide substrate. The silicon carbide ingot filled with liquid in the modified layer can be cooled by moving it into an environment where the liquid can freeze. In order to prevent the liquid in the modified layer from flowing out due to gravity during the movement, the silicon carbide ingot can be rotated in the container to make its surface parallel to the ground.

[0036] Specifically, the silicon carbide ingot filled with liquid is first rotated so that its surface is parallel to the surface of the liquid, and then the rotated silicon carbide ingot is translated from the liquid to an environment with a temperature below zero degrees for standing. The silicon carbide ingot filled with liquid can be rotated by grabbing and flipping the transfer device, and the rotated silicon carbide ingot is translated from the liquid to an environment with a temperature below zero degrees for standing.

[0037] In addition, it has been pointed out above that when the silicon carbide ingot is placed in the liquid, the grooves of the modified layer are placed in the liquid in a direction perpendicular to the surface of the liquid. Therefore, this step can be specifically implemented by first grasping and flipping the silicon carbide ingot filled with liquid in a counterclockwise direction (such as Figure 4 The arc arrow in the figure rotates the silicon carbide ingot 90 degrees to make the surface of the silicon carbide ingot parallel to the ground, and then the rotated silicon carbide ingot is translated to (such as Figure 4 The cooling device freezes the liquid inside the modified layer, and the liquid expands after freezing, causing the modified layer to break, so that the wafer layer to be peeled off is separated from the silicon carbide substrate.

[0038] Then, the process proceeds to 130 to grind the separated wafer layer to obtain a wafer. Part of the silicon carbide substrate and the modified layer may remain on the surface of the separated wafer layer. Therefore, this embodiment will further grind and remove the silicon carbide substrate and the modified layer remaining on the surface of the separated wafer layer, thereby achieving wafer peeling. Specifically, in some embodiments, a gripping device can be used to grip the separated wafer layer to a grinding device to grind its back side. In addition, in some embodiments, another gripping device can be used to grip the remaining silicon carbide ingot to the front station to grind its end face, and then use the laser to generate the modified layer of the next wafer again.

[0039] The present invention also provides a device for stripping wafers from a silicon carbide ingot, wherein, it should be noted here that the silicon carbide ingot in this embodiment includes a wafer layer to be stripped, a modified layer and a silicon carbide substrate, and the modified layer is located between the wafer layer to be stripped and the silicon carbide substrate.

[0040] Figure 4 FIG. 1 is a schematic diagram showing the structure of a device for peeling a wafer from a silicon carbide ingot according to an embodiment of the present invention. Figure 4 As shown, the device for stripping a wafer from a silicon carbide ingot comprises: a container 7 for storing a prepared liquid, an ultrasonic vibration device 8 for vibrating the liquid in the container, a clamping and lifting device 4 for placing the silicon carbide ingot in the vibrating liquid, a grabbing and flipping transfer device 9 for transferring the silicon carbide ingot filled with liquid to a cooling device after the liquid fills the modified layer of the silicon carbide ingot, a cooling device 10 for cooling the silicon carbide ingot filled with liquid so that the modified layer expands and breaks due to the freezing of the liquid inside, thereby separating the wafer layer from the silicon carbide substrate, and a grinding device (not shown in the figure) for grinding the separated wafer layer to obtain a wafer.

[0041] Specifically, in some embodiments, the silicon carbide ingot can be placed in a vibrating liquid (i.e., container 7) at a predetermined rate by means of a clamping and lifting device 4 with the grooves of its modified layer perpendicular to the surface of the liquid. After the liquid fills the modified layer, the silicon carbide ingot filled with the liquid is first rotated by means of a grabbing and flipping transfer device 9 so that its surface is parallel to the surface of the liquid, and then the rotated silicon carbide ingot is translated from the liquid to a cooling device 10.

[0042] The specific details of the device for stripping a wafer from a silicon carbide ingot according to the present invention have been described in detail based on Figures 1 to 3 The details are disclosed in the description and will not be repeated here.

[0043] The present invention can reduce material loss during silicon carbide wafer peeling, thereby effectively improving the utilization rate of silicon carbide ingots, and the present invention can also improve processing efficiency and reduce manufacturing costs.

[0044] A11. The device as described in A10, wherein the clamping and lifting device places the silicon carbide ingot into the vibrating liquid in a direction in which the grooves of the modified layer are perpendicular to the surface of the liquid. A12. The device as described in A11, wherein the clamping and lifting device places the silicon carbide ingot into the vibrating liquid in the direction at a predetermined rate. A13. The device as described in A11 or A12, wherein the grabbing, flipping and transporting device rotates the silicon carbide ingot filled with liquid so that its surface is parallel to the surface of the liquid, and translates the rotated silicon carbide ingot from the liquid to the cooling device.

[0045] In the description of this specification, unless otherwise clearly specified and limited, the terms "connected", "fixed", etc. should be understood in a broad sense. In addition, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "top", "bottom", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the equipment, unit or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore, cannot be understood as limiting the present invention.

[0046] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0047] In the description provided herein, a large number of 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.

[0048] It should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those explicitly recited in each claim. More specifically, as reflected in the above claims, inventive aspects lie in less than all of the features of the individual embodiments disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0049] Those skilled in the art should understand that the modules or units or components of the device in the examples disclosed herein may be arranged in the device as described in the embodiment, or alternatively may be located in one or more devices different from the device in the example.

[0050] Those skilled in the art will appreciate that the components in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The components in the embodiments may be combined into one component, and in addition they may be divided into multiple subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0051] 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 above claims, any one of the claimed embodiments can be used in any combination.

[0052] It should also be noted that, unless otherwise specified, the use of ordinal numbers "first", "second", "third", etc. to describe common objects merely indicates that different instances of similar objects are involved, and is not intended to imply that the objects described in this way must have a given order in time, space, sorting or in any other way.

[0053] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and teaching purposes, rather than for explaining or defining the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is illustrative, not restrictive, with respect to the scope of the present invention, which is defined by the appended claims.

Claims

1. A method for stripping a wafer from a silicon carbide ingot, wherein: The silicon carbide ingot comprises a wafer layer to be peeled off, a modified layer and a silicon carbide substrate, wherein the modified layer is located between the wafer layer and the silicon carbide substrate, and the method comprises: Injecting a pre-prepared liquid into the modified layer of the silicon carbide ingot by ultrasonic vibration, wherein the liquid is an aqueous solution with a substance capable of reducing water tension as a solute and is stored in a container, wherein injecting the pre-prepared liquid into the modified layer of the silicon carbide ingot by ultrasonic vibration comprises: vibrating the liquid in the container by an ultrasonic vibration device, and placing the silicon carbide ingot into the liquid in a direction in which the grooves of its modified layer are perpendicular to the surface of the liquid; After the liquid fills the modified layer, the silicon carbide ingot filled with the liquid is cooled until the liquid freezes to cause the modified layer to expand and break, and the wafer layer is separated from the silicon carbide substrate, wherein the cooling treatment of the silicon carbide ingot filled with the liquid includes: rotating the silicon carbide ingot filled with the liquid by a grabbing and flipping transfer device so that its surface is parallel to the surface of the liquid, and translating the rotated silicon carbide ingot from the liquid to an environment with a temperature below zero degrees for standing; Grinding the separated wafer layer to obtain the wafer; Among them, placing the silicon carbide ingot into the liquid with the grooves of its modified layer perpendicular to the surface of the liquid includes: placing the silicon carbide ingot into the liquid in the direction at a predetermined rate through a clamping and lifting device, and the predetermined rate is the rate of liquid immersion.

2. The method of claim 1, wherein: Grinding of the separated wafer layers, including: The silicon carbide substrate and the reformed layer remaining on the surface of the separated wafer layer are removed by grinding.

3. The method according to claim 1 or 2, wherein: The formation of the modified layer comprises: Positioning a focal point of a pulsed laser beam having a wavelength that is transparent to the silicon carbide ingot at a predetermined distance from a surface of the silicon carbide ingot, wherein the predetermined distance is the thickness of the wafer to be peeled off; The silicon carbide ingot is irradiated with pulsed laser light to form the modified layer.

4. A device for stripping a wafer from a silicon carbide ingot, wherein: The silicon carbide ingot comprises a wafer layer to be peeled off, a modified layer and a silicon carbide substrate, wherein the modified layer is located between the wafer layer and the silicon carbide substrate, and the device comprises: A container for storing a prepared liquid, wherein the liquid is an aqueous solution having a substance capable of reducing water tension as a solute; an ultrasonic vibrating device for vibrating the liquid in the container; A clamping and lifting device for placing the silicon carbide ingot into a vibrating liquid; A grabbing and flipping transfer device for transferring the silicon carbide ingot filled with liquid to a cooling device after the liquid fills the modified layer of the silicon carbide ingot; A cooling device for cooling a silicon carbide ingot filled with liquid, so that the modified layer expands and breaks due to the freezing of the liquid inside, and the wafer layer is separated from the silicon carbide substrate; and A grinding device for grinding the separated wafer layer to obtain the wafer; The clamping and lifting device places the silicon carbide ingot into the vibrating liquid in a direction in which the grooves of the modified layer are perpendicular to the surface of the liquid, and the clamping and lifting device places the silicon carbide ingot into the vibrating liquid in the direction at a predetermined rate, and the predetermined rate is the rate at which the liquid enters; The grabbing, flipping and transferring device rotates the silicon carbide ingot filled with liquid so that its surface is parallel to the surface of the liquid, and translates the rotated silicon carbide ingot from the liquid to the cooling device.

Images