Silicon carbide crystal ingot flat grinding detection device, detection method and grinding device

Abstract

The invention provides a silicon carbide crystal ingot flat grinding detection device and method and a grinding device.The silicon carbide crystal ingot flat grinding detection device comprises a positioning module, a moving module and a detection module; the positioning module comprises a workbench and a fixed base, and the fixed base is arranged on the workbench and used for bearing a to-be-tested crystal ingot; the moving module comprises a moving guide rail and a rotary driving mechanism which are in transmission connection, the moving guide rail is coaxially arranged in the peripheral direction of the fixed base, and the rotary driving mechanism is used for driving the moving guide rail to rotate; the detection module comprises a plurality of alignment mechanisms, the alignment mechanisms are arranged at intervals in the circumferential direction of the movable guide rail and movably connected with the movable guide rail, and detection assemblies are arranged on the alignment mechanisms and used for measuring the resistivity of the flat grinding end face of the to-be-detected crystal ingot. According to the invention, non-optical defect crack detection is realized by monitoring the resistivity change in real time during the flat grinding period of the silicon carbide crystal ingot.

Description

Technical Field

[0001] The present invention belongs to the technical field of ingot detection, and relates to a silicon carbide ingot flat grinding detection device, a detection method and a grinding device. Background Art

[0002] As a high-performance semiconductor material, 4H-SiC has the advantages of wide bandgap, high breakdown field strength, high thermal conductivity, high electron saturation drift velocity, excellent chemical stability and low defect density, which makes it perform well in high-power, high-temperature and high-frequency applications, and is widely used in power electronics, radio frequency communications and high-temperature sensors. With the maturity of production technology and the gradual decline in costs, 4H-SiC has become an important development direction of future semiconductor technology.

[0003] The flat grinding process of silicon carbide ingot is an important step in the semiconductor processing process. The purpose is to process the grown silicon carbide into an ingot with a flat surface and precise thickness. The flat grinding process can not only improve the surface quality and dimensional accuracy of the ingot, but also lay a good foundation for subsequent processing steps (such as slicing, grinding, polishing, etc.).

[0004] At present, cracks often appear in silicon carbide ingots during the flat grinding process due to process reasons. However, due to the influence of grinding coolant, operators cannot visually check the cracks. In addition, the single flat grinding time of silicon carbide ingots is relatively long, and it is difficult to re-align and restart the flat grinding process if it is stopped in the middle, which makes it difficult to detect defects and cracks in the middle of flat grinding in time.

[0005] Therefore, how to grasp the occurrence of defects and cracks in the flat grinding of silicon carbide ingots in real time has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a silicon carbide ingot flat grinding detection device, detection method and grinding device, which can monitor the resistivity changes of the silicon carbide ingot in real time during the flat grinding of the silicon carbide ingot, and then judge the current defect crack situation of the ingot, thereby realizing non-optical detection of defect cracks and facilitating timely adjustment to reduce losses.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a silicon carbide ingot flat grinding detection device, comprising a positioning module, a moving module and a detection module; the positioning module comprises a workbench and a fixed base, the fixed base is arranged on the workbench, and the fixed base is used to carry the ingot to be tested; the moving module comprises a moving guide rail and a rotating drive mechanism connected by a transmission connection, the moving guide rail is coaxially arranged along the outer circumference of the fixed base, and the rotating drive mechanism is used to drive the moving guide rail to rotate; the detection module comprises a plurality of alignment mechanisms, the plurality of alignment mechanisms are circumferentially spaced along the moving guide rail and movably connected to the moving guide rail, a detection component is arranged on the alignment mechanism, and the detection component is used to measure the resistivity of the flat grinding end face of the ingot to be tested.

[0009] The present invention utilizes a fixed base to support the crystal ingot to be tested, and uses an alignment mechanism to perform all-round real-time monitoring of the resistivity of the crystal ingot surface, thereby realizing non-optical detection of defect cracks. At the same time, the rotation of the movable guide rail is used to drive the alignment mechanism to move along the periphery of the crystal ingot, thereby monitoring different positions of the crystal ingot to ensure the stability and accuracy of the detection.

[0010] It should be noted that the flat-ground end face mentioned in the present invention refers to the end face of the crystal ingot to be measured close to the grinding equipment during the flat-ground process, that is, the top surface of the crystal ingot to be measured.

[0011] As a preferred technical solution of the present invention, the movable guide rail includes a guide rail body and a plurality of fixed wheels, and the upper and lower ends of the guide rail body are respectively provided with guide steps and transmission gear rings, and the plurality of fixed wheels are circumferentially arranged along the outer circumference of the guide rail body and slidably connected to the guide steps; a plurality of limiting grooves are circumferentially opened along the end surface of the guide step, and the limiting grooves extend radially along the guide step; the alignment mechanism is movably connected to the limiting grooves so that the alignment mechanism moves horizontally in the limiting grooves toward or away from the fixed base; the transmission gear ring is transmission-connected to the rotation drive mechanism.

[0012] As a preferred technical solution of the present invention, the fixed wheel includes a base, the base is fixedly connected to the workbench, a guide rail positioning groove is provided on the top of the base, the edge portion of the guide step is located in the guide rail positioning groove, and slides horizontally along the inside of the guide rail positioning groove.

[0013] In the present invention, the guide rail positioning groove cooperates with the guide step to ensure that the guide step performs horizontal relative rotation, thereby preventing the movable guide rail from deflecting and affecting the detection accuracy.

[0014] Preferably, a first limiting wheel and a second limiting wheel are rotatably provided on the top of the base, the first limiting wheel and the second limiting wheel are arranged side by side, and the guide rail positioning groove is formed between the first limiting wheel and the second limiting wheel.

[0015] As a preferred technical solution of the present invention, the rotary drive mechanism includes a driving wheel and a driving gear ring, the driving wheel is located outside the movable guide rail, the driving gear ring is sleeved on the outer periphery of the driving wheel and meshes with the transmission gear ring.

[0016] As a preferred technical solution of the present invention, the alignment mechanism includes a detection contact, a supporting arm and a contact slide; one end of the detection contact has a detection surface, the detection component is arranged on the detection surface, and the other end of the detection contact is rotatably connected to the supporting arm; the end of the supporting arm away from the detection contact is also rotatably connected to the limiting groove; the orthographic projection of the contact slide on the plane where the detection contact is located at least partially covers the detection component, one end of the contact slide has a contact end, and the other end is slidably connected to the detection contact, so that the contact end of the contact slide moves along the extension direction of the detection contact and extends out of the detection component.

[0017] The alignment mechanism of the present invention can not only move horizontally along the limiting groove by using the supporting connecting arm, but also swing with the arm length of the supporting connecting arm as the radius. In addition, multiple groups of detection components of different types can be arranged on the detection surface of the present invention to perform various forms of resistivity detection work at the same detection site, thereby ensuring the stability of the detection data.

[0018] Preferably, the contact sliding cover is sleeved on the outer periphery of the detection contact.

[0019] Preferably, the supporting connecting arm is in an inverted "L" shape.

[0020] In the present invention, the contact slide cover is slidably arranged on the periphery of the detection contact to protect the detection surface. It can move along the detection surface toward the relative detection contact. Its sliding tendency is affected by damping and relative sliding needs to be achieved after additional pressure is applied.

[0021] As a preferred technical solution of the present invention, the silicon carbide ingot flat grinding detection device also includes a purge module, the purge module includes a gas supply component and a plurality of purge components, the gas supply component is respectively connected to a plurality of the purge components for providing purge gas, the purge component is fixedly connected to the alignment mechanism for purging and removing residual liquid on the surface of the ingot to be tested.

[0022] The present invention purges and dries the residual liquid on the surface of the ingot to be tested to avoid being affected by the residual liquid. Since the operator cannot directly check the crack condition of the ingot, the residual liquid on the surface can also prevent the operation of the detection component from being affected, thereby avoiding increasing the detection error and reducing the data accuracy.

[0023] It should be noted that the residual liquid in the present invention refers to the grinding coolant used in the flat grinding process.

[0024] Preferably, the purge assembly includes at least one purge nozzle, which is disposed on the detection surface of the detection contact and is connected to the gas supply assembly for spraying purge gas.

[0025] In the present invention, under the protection of the contact slider, the detection component and the purge nozzle located on the detection surface are prevented from contacting with the residual liquid.

[0026] In a second aspect, the present invention provides a method for detecting flat grinding of a silicon carbide ingot, wherein the detection method adopts the silicon carbide ingot flat grinding detection device described in the first aspect, and the detection method comprises:

[0027] Bonding the ingot to be tested onto a fixed base;

[0028] Starting the alignment mechanism, so that a plurality of alignment mechanisms are synchronously moved horizontally toward the direction of the crystal ingot to be measured, and detecting the resistivity of the surface of the crystal to be measured. After the detection is completed, the alignment mechanism is reset;

[0029] The rotating movable guide rail drives the alignment mechanism to rotate, so as to detect the resistivity of different positions of the flat ground end surface of the ingot to be tested.

[0030] As a preferred technical solution of the present invention, the starting alignment mechanism includes: horizontally moving the alignment mechanism in a direction away from the crystal ingot to be measured to the end point of the path of the limiting groove; rotating the supporting connecting arm of the alignment mechanism so that the supporting connecting arm and the bottom surface of the limiting groove are set at an angle; and then rotating the detection contact of the alignment mechanism so that the detection contact and the contact slide are both horizontally set toward the crystal ingot to be measured, and the contact slide is lower than the flat-ground end surface of the crystal ingot to be measured.

[0031] It should be noted that the end point of the path in the present invention refers to the farthest end point that the alignment mechanism can reach by horizontally moving along the limiting groove in a direction away from or close to the fixed base, and will not fall off the limiting groove. The contact slide cover is lower than the flat grinding end face of the crystal ingot to be measured in the present invention means that the height of the upper end face of the contact slide cover is lower than the height of the flat grinding end face of the crystal ingot to be measured, so as to avoid affecting the flat grinding operation.

[0032] Preferably, the detection process includes: ensuring that the contact end of the contact slide of the alignment mechanism extends out of the detection surface, moving the alignment mechanism horizontally in a direction close to the crystal ingot to be measured until the contact slide touches the outer wall of the crystal ingot to be measured, and stopping the horizontal movement of the alignment mechanism; rotating the supporting connecting arm of the alignment mechanism to drive the contact slide and the detection contact to move synchronously, so that the vertical spacing L1 from the contact end of the contact slide to the flat-ground end surface of the crystal ingot to be measured satisfies 0.5mm≤L1≤1mm; then continuing to move the alignment mechanism horizontally in a direction close to the crystal ingot to be measured until the detection contact contacts the outer wall of the crystal ingot to be measured, and using the detection component to collect the resistivity data of the flat-ground end surface of the crystal ingot to be measured.

[0033] It should be noted that the vertical spacing refers to the distance in the vertical direction from the upper end surface of the contact end of the contact slide cover to the flat-ground end surface of the crystal ingot to be measured.

[0034] Preferably, the resetting process includes: horizontally moving the alignment mechanism in a direction away from the crystal ingot to be measured to the end point of the path of the limiting groove, and rotating the detection contact so that the detection contact and the contact slide cover rotate synchronously until they are parallel to the supporting arm, and then adjusting the supporting arm so that it is arranged parallel to the bottom surface of the limiting groove and is in a storage state; then horizontally moving the alignment mechanism in the storage state again in a direction close to the crystal ingot to be measured to clear the relative displacement between the detection contact and the contact slide cover.

[0035] After the detection is completed, the alignment mechanism can be stored in the limiting groove to avoid obstruction to the rotation of the movable guide rail.

[0036] Preferably, when the number of the alignment mechanisms is N, N≥2, and the single rotation angle of the movable guide rail is 0° to 360° / N.

[0037] As a preferred technical solution of the present invention, the method for testing the flat grinding of silicon carbide ingots further comprises: before the testing, spraying a purge gas onto the flat grinding end surface of the ingot to be tested to purge away residual liquid.

[0038] In a third aspect, the present invention provides a grinding device, wherein the grinding device comprises the silicon carbide ingot flat grinding detection device described in the first aspect.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention provides a silicon carbide ingot flat grinding detection device, detection method and grinding device, which can monitor the resistivity change of the silicon carbide ingot in real time during the flat grinding process, and perform precise detection at different positions and depths of the silicon carbide ingot to accurately determine the current defect crack situation of the ingot, so as to facilitate timely adjustment of the grinding state to reduce losses and improve the work efficiency of the processing production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic structural diagram of the silicon carbide ingot flat grinding detection device provided by the present invention.

[0042] Figure 2 This is a schematic diagram of the structure of the alignment mechanism provided by the present invention when it extends out of the limiting groove.

[0043] Figure 3 A schematic diagram of the structure of the alignment mechanism provided by the present invention when it is in a stored state;

[0044] Figure 4 The schematic diagram of the structure of the alignment mechanism provided by the present invention after clearing the relative displacement between the detection contact and the contact slide cover.

[0045] Among them, 11-fixed base; 21-movable guide rail; 211-guide step; 212-transmission gear ring; 22-driving wheel; 221-driving gear ring; 23-fixed wheel; 231-guide rail positioning groove; 24-limiting groove; 30-alignment mechanism; 31-support arm; 32-detection contact; 321-detection surface; 33-contact slide cover; 50-ingot; 41-detection component; 42-purge nozzle. DETAILED DESCRIPTION

[0046] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0047] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0048] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0049] In a specific embodiment, the present invention provides a silicon carbide ingot flat grinding detection device, which can monitor the surface defects of the ingot in the flat grinding process in real time, and specifically includes a positioning module, a moving module and a detection module. The positioning module includes a workbench and a fixed base, the workbench can reciprocate relative to the flat grinding machine in the horizontal direction, the fixed base is arranged on the workbench, and the fixed base is used to carry the ingot to be tested to ensure the stability of the ingot to be tested during the flat grinding process. The ingot to be tested is usually a cylindrical structure, which is fixed to the fixed base by bonding. The moving module includes a moving guide rail and a rotating drive mechanism connected by transmission, the moving guide rail is arranged coaxially along the outer circumference of the fixed base, and the rotating drive mechanism is used to drive the moving guide rail to rotate along the circumference of the ingot to be tested. The detection module includes a plurality of alignment mechanisms, which are arranged at intervals along the circumference of the moving guide rail, and are movably connected to the moving guide rail, and can rotate with the rotation of the moving guide rail. The alignment mechanism is provided with a detection component, and the detection component is used to measure the resistivity of the flat grinding end face of the ingot to be tested. The present invention does not specifically limit the type of detection component, and the resistivity of different detection depths or detection ranges can be measured by the four-probe method and / or eddy current detection method commonly used in the field. When defects such as cracks or pits appear on the surface of the ingot, the corresponding position presents a high resistance anomaly, and the real-time resistivity measurement can promptly confirm whether the ingot has defects.

[0050] In some embodiments, the movable guide rail includes a guide rail body and a plurality of fixed wheels, and the upper and lower ends of the guide rail body are respectively provided with a guide step and a transmission gear ring. The plurality of fixed wheels are arranged circumferentially along the outer periphery of the guide rail body and are slidably connected to the guide step. The fixed wheel is used to limit the movable guide rail to ensure that it rotates along the horizontal plane, which is conducive to improving the stability and accuracy of data detection. The transmission gear ring is connected to the rotation drive mechanism in a transmission manner, thereby driving the movable guide rail to rotate horizontally along the circumference. A plurality of limiting grooves are provided along the circumference of the end surface of the guide step, and the limiting grooves extend radially along the guide step. The alignment mechanism is movably connected to the limiting grooves to arrange and install the alignment mechanism on the movable guide rail, and to enable the alignment mechanism to move horizontally in the limiting groove in a direction close to or away from the fixed base. The present invention does not specifically limit the movable connection mode between the alignment mechanism and the limiting groove, and can adopt sliding connection, hinge connection, meshing connection, connecting rod connection, etc. well known to those skilled in the art, as long as any movable connection mode that can realize the relative sliding of the alignment mechanism along the limiting groove can be applied to the present invention.

[0051] Specifically, the fixed wheel includes a base, the base is fixedly connected to the workbench, the base is fixed to the workbench, a guide rail positioning groove is arranged on the top of the base, the edge of the guide step is located in the guide rail positioning groove, and slides horizontally along the inside of the guide rail positioning groove, the guide rail positioning groove and the guide step cooperate with each other to ensure the stability of the rotation of the mobile track. Further, the top of the base is rotatably provided with a first limiting wheel and a second limiting wheel, the first limiting wheel and the second limiting wheel are arranged side by side, and the guide rail positioning groove is formed between the first limiting wheel and the second limiting wheel.

[0052] Specifically, the rotary drive mechanism includes a driving wheel and a driving gear ring. The driving wheel is located outside the movable guide rail and fixed on the workbench. The driving gear ring is sleeved on the outer periphery of the driving wheel and meshes with the transmission gear ring, thereby driving the movable guide rail to rotate.

[0053] In some embodiments, the alignment mechanism includes a detection contact, a supporting link arm, and a contact slide cover.

[0054] One end of the detection contact has a detection surface, and the detection component is arranged on the detection surface. When the detection is carried out, the detection surface detects the main body of the crystal ingot to be tested along the radial direction of the crystal ingot to be tested, which is the detection direction; the other end of the detection contact is rotatably connected to the supporting arm.

[0055] The end of the supporting connecting arm away from the detection contact is also rotatably connected to the limiting groove, so that the supporting connecting arm can not only move horizontally along the limiting groove, but also swing with the connection point between the supporting connecting arm and the limiting groove as the center of the circle and the arm length of the supporting connecting arm as the radius, thereby adjusting the angle of the alignment mechanism. Specifically, the supporting connecting arm is in an inverted "L" shape, the bottom of its vertical part is movably connected to the limiting groove, and its horizontal part is rotatably connected to the detection contact, and the angle between the vertical part and the horizontal part is ≥90°.

[0056] The orthographic projection of the contact slide on the plane where the detection contact is located at least partially covers the detection component, and one end of the contact slide has a contact end, and the other end is slidably connected to the detection contact, so that the contact end of the contact slide moves along the extension direction of the detection contact and extends out of the detection component. The contact end of the contact slide refers to the end close to the side of the crystal ingot to be tested during the detection. Specifically, the contact slide is sleeved on the outer periphery of the detection contact, and its sliding tendency is affected by damping, and it is necessary to apply additional pressure to slide relative to it. The present invention does not specifically limit the sliding connection method between the contact slide and the detection contact, as long as any connection method that can realize the relative sliding of the contact slide and the detection contact can be applied to the present invention. Exemplarily, a slider is provided at one end of the detection contact away from the detection surface, and the contact slide is sleeved on the outer periphery of the detection contact by the side of the detection contact away from the detection surface, and the two sides of the contact slide are provided with slide grooves, so that the slider can move along the slide grooves.

[0057] The detection component includes a detection probe arranged on the detection surface, and must also include other necessary connecting wires, signal detection lines, universal terminal equipment, etc. for realizing the complete process. However, the above content does not belong to the main invention point of the invention. Technical personnel in this field can add layouts on their own based on the process flow and equipment structure selection. The present invention does not make special requirements and specific limitations on this.

[0058] In some embodiments, the silicon carbide ingot flat grinding detection device further includes a purge module, the purge module includes a gas supply component and a plurality of purge components, the gas supply component is respectively connected to the plurality of purge components for providing purge gas, the purge component is fixedly connected to the alignment mechanism for purging and removing residual liquid on the surface of the ingot to be tested. Specifically, the purge component includes at least one purge nozzle, the purge nozzle is arranged on the detection surface of the detection contact, the purge nozzle is connected to the gas supply component for spraying purge gas. The residual liquid is the grinding coolant required for flat grinding of the ingot to be tested. The gas supply component includes a plurality of gas supply pipelines for realizing a complete process, which are respectively arranged inside the alignment mechanism and are interconnected with the corresponding purge nozzles to provide purge gas, and the plurality of gas supply pipelines can be gathered into one inside the guide rail body.

[0059] It should be noted that the purge module must also include other necessary pipelines, conventional valves, general pump equipment, etc. for realizing the complete process, but the above content does not belong to the main invention point of the invention. Technical personnel in this field can add layouts on their own based on the process flow and equipment structure selection. The present invention does not make special requirements and specific limitations on this.

[0060] During the application of the present invention, the residual liquid is blown dry by the purge nozzle under the protection of the contact slide cover, and when the target area is dry, the supporting arm is moved to make the detection surface close to the ingot to be tested to detect the conductivity.

[0061] In another specific embodiment, the present invention provides a method for detecting flat grinding of a silicon carbide ingot, wherein the detection method uses a silicon carbide ingot flat grinding detection device according to a specific embodiment, and the detection method comprises:

[0062] Bonding the ingot to be tested onto a fixed base;

[0063] Starting the alignment mechanism, so that a plurality of alignment mechanisms are synchronously moved horizontally toward the direction of the crystal ingot to be measured, and detecting the resistivity of the surface of the crystal to be measured. After the detection is completed, the alignment mechanism is reset;

[0064] The rotating movable guide rail drives the alignment mechanism to rotate, so as to detect the resistivity of different positions of the flat ground end surface of the ingot to be tested.

[0065] In some embodiments, starting the alignment mechanism includes: moving the alignment mechanism horizontally in a direction away from the crystal ingot to be measured to the end point of the path of the limiting groove; rotating the support arm of the alignment mechanism so that the support arm and the bottom surface of the limiting groove are set at an angle; and then rotating the detection contact of the alignment mechanism so that the detection contact and the contact slide are both set horizontally toward the crystal ingot to be measured, and the contact slide is lower than the flat-ground end surface of the crystal ingot to be measured.

[0066] In some embodiments, the detection process includes: ensuring that the contact end of the contact slide of the alignment mechanism extends out of the detection surface, moving the alignment mechanism horizontally in a direction close to the crystal ingot to be measured until the contact slide touches the outer wall of the crystal ingot to be measured, and stopping the horizontal movement of the alignment mechanism; rotating the supporting connecting arm of the alignment mechanism to drive the contact slide and the detection contact to move synchronously, so that the vertical spacing L1 from the contact end of the contact slide to the flat-ground end surface of the crystal ingot to be measured satisfies 0.5mm≤L1≤1mm; then continuing to move the alignment mechanism horizontally in a direction close to the crystal ingot to be measured until the detection contact contacts the outer wall of the crystal ingot to be measured, and using the detection component to collect the resistivity data of the flat-ground end surface of the crystal ingot to be measured.

[0067] If L1 is too large, it will affect the detection effect of the detection component on the edge and center of the crystal ingot. If L1 is too small, it will easily increase the risk of contact between the contact slide and the flat grinding wheel. Since the height of the flat grinding end face of the crystal ingot to be tested decreases as the flat grinding operation progresses during the detection, the present invention needs to adjust the alignment mechanism to ensure that the vertical spacing from the contact end of the contact slide to the flat grinding end face of the crystal ingot to be tested meets the above conditions.

[0068] In some embodiments, the resetting process includes: horizontally moving the alignment mechanism in a direction away from the crystal ingot to be measured to the end point of the path of the limiting groove, and rotating the detection contact so that the detection contact and the contact slide cover rotate synchronously until they are parallel to the supporting arm, and then adjusting the supporting arm so that it is arranged parallel to the bottom surface of the limiting groove and is in a storage state; then horizontally moving the alignment mechanism in the storage state again in a direction close to the crystal ingot to be measured to clear the relative displacement between the detection contact and the contact slide cover. In the process of the alignment mechanism in the storage state gradually moving horizontally to the end point of the path of the limiting groove, the end of the contact slide cover away from the contact end touches and abuts against the outer contour of the limiting groove, and as the supporting arm continues to move, the relative displacement between the previous contact slide cover and the detection contact is cleared again.

[0069] In some embodiments, when the number of the alignment mechanisms is N, N≥2, the single rotation angle of the movable rail is 0° to 360° / N. In the present invention, the number m of detection sites required for the periphery of the ingot to be measured is not less than 10, and m is preferably an integer multiple of N.

[0070] In some embodiments, the detection method further comprises: before the detection, spraying a purge gas onto the flat-ground end surface of the crystal ingot to be detected to purge away residual liquid.

[0071] In the actual application process of the present invention, it is necessary to first collect the resistivity data of the initial state of the crystal ingot to be tested before the flat grinding operation, and compare it with the real-time conductivity data collected during the subsequent flat grinding operation, calculate the difference between the two, and then analyze and judge the state of the surface of the crystal ingot to be tested.

[0072] In another specific embodiment, the present invention provides a grinding device, the grinding device includes a silicon carbide crystal ingot flat grinding detection device described in a specific embodiment. The grinding device must include a flat grinding machine tool necessary for realizing the process completion, the worktable of the silicon carbide crystal ingot flat grinding detection device can reciprocate relative to the flat grinding machine tool in the horizontal direction, and then adjust the position of the crystal ingot, and use the flat grinding equipment with the assistance of grinding coolant to perform flat grinding on the flat grinding end surface of the crystal ingot, and the silicon carbide crystal ingot flat grinding detection device is used to perform real-time detection of defects existing at different locations on the flat grinding end surface of the crystal ingot.

[0073] Example 1

[0074] This embodiment provides a silicon carbide ingot 50 flat grinding detection device, including a positioning module, a moving module, a detection module and a purging module. The positioning module includes a workbench and a fixed base 11, and the fixed base 11 is arranged at the center of the workbench, such as Figure 1As shown, the fixed base 11 is used to carry the crystal ingot 50 to be tested. The mobile module includes a mobile guide rail 21 and a rotating drive mechanism that are transmission-connected. The mobile guide rail 21 includes a guide rail body and six fixed wheels 23. The guide rail body is coaxially arranged along the outer circumference of the fixed base 11. The upper and lower ends of the guide rail body are respectively provided with a guide step 211 and a transmission gear ring 212. Three limiting grooves 24 are opened along the circumference of the end face of the guide step 211, and the limiting grooves 24 extend radially along the guide step 211. The rotating drive mechanism includes a driving wheel 22 and a driving gear ring 221. The driving wheel 22 is located outside the mobile guide rail 21 and fixed on the workbench. The driving gear ring 221 is sleeved on the outer circumference of the driving wheel 22 and meshes with the transmission gear ring 212. The six fixed wheels 23 are arranged circumferentially along the outer circumference of the guide rail body and are slidably connected to the guide step 211. The fixed wheel 23 includes a base fixed on the workbench, and a first limiting wheel and a second limiting wheel are rotatably arranged on the top of the base, and the first limiting wheel and the second limiting wheel are arranged side by side, and a guide rail positioning groove 231 is formed between the first limiting wheel and the second limiting wheel. The edge of the guide step 211 is located in the guide rail positioning groove 231, and slides horizontally along the inside of the guide rail positioning groove 231.

[0075] like Figure 2 and Figure 3 As shown, the detection module includes three alignment mechanisms 30, which are arranged at intervals along the circumference of the movable guide rail 21 and are movably connected to the limiting groove 24. The alignment mechanism 30 includes a detection contact 32, a support arm 31 and a contact slide 33. One end of the detection contact 32 has a detection surface 321, and a detection component 41 is arranged on the detection surface 321 for measuring the resistivity data of the flat grinding end surface of the crystal ingot 50. The other end of the detection contact 32 is rotatably connected to the support arm 31, and the end of the support arm 31 away from the detection contact 32 is also rotatably connected to the limiting groove 24, so that the support arm 31 can move horizontally along the limiting groove 24 to drive the alignment mechanism 30 to move toward or away from the crystal ingot 50 on the fixed base 11, and can also swing with the connection point with the limiting groove 24 as the center and the arm length of the support arm 31 as the radius. The orthographic projection of the contact slide 33 on the plane where the detection contact 32 is located can cover the detection component 41. One end of the contact slide 33 has a contact end, and the other end is sleeved on the outer periphery of the detection contact 32 on the side away from the detection surface 321, and is slidably connected to the detection contact 32, so that the contact end of the contact slide 33 moves along the extension direction of the detection contact 32 and extends out of the detection component 41.

[0076] The purge module includes a gas supply component and three purge components, and the gas supply components are respectively connected to the three purge components for providing purge gas. Each purge component independently includes two purge nozzles 42, and the two purge nozzles 42 are fixed on the detection surface 321 of the detection contact 32, and are respectively located on both sides of the detection component 41. The purge nozzles 42 are connected to the gas supply component and are used to spray purge gas to the flat grinding end surface of the ingot 50 to be tested to purge and remove residual liquid.

[0077] Application Example 1

[0078] This application example uses the silicon carbide ingot flat grinding detection device provided in Example 1 to detect the ingot on the flat grinding machine, and specifically includes the following steps:

[0079] S110 : Fix the fixed base 11 to which the crystal ingot 50 is bonded above the workbench so that the distance between the inner surface of the movable guide rail 21 and the outer cylindrical surface of the crystal ingot 50 remains consistent.

[0080] S120: Start the alignment mechanism 30. After the support arm 31 moves horizontally relative to the limiting groove 24 to the end of the path in a direction away from the fixed base 11, the support arm 31 and the detection contact 32 are respectively rotated and extended from the limiting groove 24 from the horizontal initial storage state, and the rotation angle between the support arm 31 and the horizontal plane is less than 90°. After the rotation, the detection contact 32 and the contact slide cover 33 are always located in the horizontal direction, and the contact slide cover 33 is lower than the flat-ground end surface of the crystal ingot 50 to be measured.

[0081] S130: Ensure that the contact end of the contact slide 33 of the alignment mechanism 30 extends out of the detection surface 321, and gradually move the supporting arm 31 horizontally in the limiting groove 24 toward the fixed base 11 until the contact end of the contact slide 33 touches the outer cylindrical surface of the crystal ingot 50. At this time, the supporting arm 31 stops moving horizontally, and measure the vertical spacing L1 between the contact end of the contact slide 33 and the flat-ground end surface of the crystal ingot 50. Repeatedly rotate the alignment mechanism until 0.5mm≤L1≤1mm is satisfied.

[0082] S140: Continue to move the supporting arm 31 horizontally toward the fixed base 11, and keep the contact slide cover 33 in position until the detection contact 32 contacts the cylindrical surface of the crystal ingot 50, record the maximum height of the alignment mechanism 30, and use the detection component 41 to perform preliminary detection of the resistivity of the crystal ingot 50 to obtain initial detection data for subsequent comparison.

[0083] S150: Figure 3 and Figure 4As shown, the support arm 31 is horizontally moved in a direction away from the fixed base 11 to the end point of the path of the limiting groove 24 away from the crystal ingot 50, and the support arm 31 and the detection contact 32 are rotated to a horizontal position, so that the alignment mechanism 30 is in a storage state. At this time, the support arm 31 is gradually horizontally moved in a direction close to the fixed base 11 to the end point of the path of the limiting groove 24 close to the crystal ingot 50. During this period, the end of the contact slider 33 away from the contact end touches the limiting contour of the limiting groove 24. With the continuous movement of the support arm 31, the relative displacement between the previous contact slide cover 33 and the detection contact 32 is cleared again, completing a single alignment work.

[0084] S160: After finishing a single alignment work, rotate the driving wheel 22, and the movable guide rail 21 rotates synchronously under the meshing of the transmission gear ring 212 and the driving gear ring 221, so that the alignment mechanism 30 located on the movable guide rail 21 rotates around the fixed base 11, and the alignment mechanism 30 reaches the next detection point under the drive of the movable guide rail 21, wherein the reciprocating rotation angle α of the movable guide rail 21 should satisfy 0°≤α≤120°. After the rotation, repeat the resistivity detection steps of steps S120 to S150 to collect the resistivity data of the silicon carbide ingot at different locations to improve the stability of the calibration data.

[0085] S170: Start the flat grinding operation of the crystal ingot. The alignment mechanism 30 synchronizes the grinding data of the flat grinding machine and calculates the real-time height of the crystal ingot surface according to the flat grinding process settings, so as to maintain the vertical spacing L1 to meet 0.5mm≤L1≤1mm during subsequent inspection. The alignment mechanism 30 can ensure that the detection contact 32 is not affected by the grinding coolant when no inspection is performed.

[0086] S180: Assume that the total grinding time of the crystal ingot 50 is T, and a round of inspection is performed every T / 10 time. When T≥10h, the minimum inspection time interval is not less than 1h. Each round of inspection is performed on the entire periphery of the crystal ingot 50. After the alignment mechanism 30 performs inspection at the initial position of the movable guide rail 21, it needs to rotate with the movable guide rail 21 to the next position for re-inspection, and the number of inspection points required for the periphery of the crystal ingot 50 is 12.

[0087] S190: When the first round of detection time is reached, the support arm 31 is moved horizontally in the direction away from the fixed base 11 to the end point of the path of the limiting groove 24 away from the ingot 50. First, the support arm 31 is rotated upward so that L1 of the contact slide 33 satisfies 0.5mm≤L1≤1mm, and then the detection contact 32 is rotated, and the contact slide 33 is synchronously rotated to a horizontal position, and the detection surface 321 is opposite to the outer cylindrical surface of the ingot 50. At this time, the support arm 31 is gradually moved horizontally in the direction close to the fixed base 11 again. When the contact end of the contact slider 33 touches the cylindrical surface of the ingot 50, the support arm 31 stops horizontal movement, and the purge nozzle 42 located on the detection surface 321 will avoid contact with the grinding coolant under the protection of the contact slider 33; then the purge nozzle 42 is turned on to dry the grinding coolant remaining in the target detection area. When it is dry, continue to move the support arm 31 close to the fixed base. The support arm 31 is gradually moved horizontally in the direction of the seat 11 until the detection contact 32 contacts the outer cylindrical surface of the crystal ingot 50, and the real-time resistivity of the crystal ingot 50 is detected for the first time by using the detection component 41, and the state of the crystal ingot surface is analyzed and judged by comparing the difference between the real-time resistivity and the initial conductivity data; after the detection, the support arm 31 is horizontally moved in the direction away from the fixed base 11 to the end point of the path of the limiting groove 24 away from the crystal ingot 50, the support arm 31 and the detection contact 32 are rotated to a horizontal position and are in a storage state, and then the support arm 31 is gradually moved horizontally in the direction close to the fixed base 11 to the end point of the path of the limiting groove 24 close to the crystal ingot 50, during which the end of the contact slider 33 away from the contact end touches the limiting contour of the limiting groove 24, and with the continuous movement of the support arm 31, the relative displacement between the contact slider 33 and the detection contact 32 is cleared again.

[0088] S200: After a single test is completed, the driving wheel 22 is rotated, and the movable guide rail 21 rotates synchronously under the meshing action of the transmission gear ring 212 and the driving gear ring 221, so that the alignment mechanism 30 located on the movable guide rail 21 rotates around the fixed base 11, and the alignment mechanism 30 reaches the next detection point under the drive of the movable guide rail, wherein the reciprocating rotation angle α of the movable guide rail 21 should satisfy 0°≤α≤120°, thereby reducing the rotation amplitude of the movable guide rail 21, and repeat the resistivity detection step of step S190 after rotation to collect the resistivity data of the silicon carbide ingot at different locations.

[0089] The present invention can monitor the resistivity change of the silicon carbide ingot in real time during the flat grinding process to accurately judge the current defect crack situation of the ingot, so as to facilitate timely adjustment to reduce losses; at the same time, through the combination of multiple detection methods and mobile detection methods, accurate detection is performed on different positions and depths of the silicon carbide ingot; in addition, through the design of the purge module and the contact slide cover, the adverse effect of the grinding coolant on the detection result is reduced, and the detection link does not affect the normal progress of the flat grinding operation, which effectively improves the efficiency of the entire silicon carbide wafer processing production line.

[0090] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A silicon carbide ingot flat grinding detection device, characterized in that: It includes a positioning module, a moving module and a detection module; the positioning module includes a workbench and a fixed base, the fixed base is arranged on the workbench, and the fixed base is used to carry the crystal ingot to be tested; the moving module includes a moving guide rail and a rotating drive mechanism connected by transmission, the moving guide rail is arranged along the outer circumference of the fixed base and coaxially, and the rotating drive mechanism is used to drive the moving guide rail to rotate; The detection module includes a plurality of alignment mechanisms, which are arranged at intervals along the circumference of the movable guide rail and are movably connected to the movable guide rail. A detection component is arranged on the alignment mechanism, and the detection component is used to measure the resistivity of the flat-ground end face of the crystal ingot to be tested.

2. The silicon carbide ingot flat grinding detection device according to claim 1, characterized in that: The movable guide rail comprises a guide rail body and a plurality of fixed wheels, wherein the upper and lower ends of the guide rail body are respectively provided with a guide step and a transmission gear ring, and the plurality of fixed wheels are circumferentially arranged along the outer circumference of the guide rail body and slidably connected to the guide step; A plurality of limiting grooves are provided along the circumference of the end surface of the guide step, the limiting grooves extend along the radial direction of the guide step, and the alignment mechanism is movably connected to the limiting grooves, so that the alignment mechanism moves horizontally in the limiting grooves toward or away from the fixed base; The transmission ring gear is transmission-connected to the rotary drive mechanism.

3. The silicon carbide ingot flat grinding detection device according to claim 2, characterized in that: The fixed wheel comprises a base, the base is fixedly connected to the workbench, a guide rail positioning groove is arranged on the top of the base, an edge portion of the guide step is located in the guide rail positioning groove, and slides horizontally along the inside of the guide rail positioning groove; Preferably, a first limiting wheel and a second limiting wheel are rotatably provided on the top of the base, the first limiting wheel and the second limiting wheel are arranged side by side, and the guide rail positioning groove is formed between the first limiting wheel and the second limiting wheel.

4. The silicon carbide ingot flat grinding detection device according to claim 2 or 3, characterized in that: The rotary drive mechanism comprises a driving wheel and a driving gear ring. The driving wheel is located outside the movable guide rail. The driving gear ring is sleeved on the outer periphery of the driving wheel and meshes with the transmission gear ring.

5. The silicon carbide ingot flat grinding detection device according to claim 2, characterized in that: The alignment mechanism comprises a detection contact, a supporting connecting arm and a contact sliding cover; One end of the detection contact has a detection surface, the detection component is arranged on the detection surface, and the other end of the detection contact is rotatably connected to the supporting arm; One end of the supporting connecting arm away from the detecting contact is also rotatably connected to the limiting groove; The orthographic projection of the contact slide cover on the plane where the detection contact is located at least partially covers the detection component, one end of the contact slide cover has a contact end portion, and the other end is slidably connected to the detection contact, so that the contact end portion of the contact slide cover moves along the extension direction of the detection contact and extends out of the detection component; Preferably, the contact sliding cover is sleeved on the outer periphery of the detection contact; Preferably, the supporting link is in an inverted "L" shape.

6. The silicon carbide ingot flat grinding detection device according to claim 5, characterized in that: The silicon carbide ingot flat grinding detection device further includes a purge module, the purge module includes a gas supply component and a plurality of purge components, the gas supply component is respectively connected to a plurality of the purge components for providing purge gas, the purge component is fixedly connected to the alignment mechanism for purging and removing residual liquid on the surface of the ingot to be tested; Preferably, the purge assembly includes at least one purge nozzle, which is disposed on the detection surface of the detection contact and is connected to the gas supply assembly for spraying purge gas.

7. A method for detecting flat grinding of silicon carbide ingots, characterized in that: The detection method adopts the silicon carbide ingot flat grinding detection device according to any one of claims 1 to 6, and the detection method comprises: Bonding the ingot to be tested onto a fixed base; Starting the alignment mechanism, so that a plurality of alignment mechanisms are synchronously moved horizontally toward the direction of the crystal ingot to be measured, and detecting the resistivity of the surface of the crystal to be measured. After the detection is completed, the alignment mechanism is reset; The rotating movable guide rail drives the alignment mechanism to rotate, so as to detect the resistivity of different positions of the flat ground end surface of the ingot to be tested.

8. The method for detecting flat grinding of silicon carbide ingot according to claim 7, characterized in that: The starting alignment mechanism comprises: horizontally moving the alignment mechanism in a direction away from the crystal ingot to be measured to the end point of the path of the limiting groove; rotating the supporting connecting arm of the alignment mechanism so that the supporting connecting arm and the bottom surface of the limiting groove are arranged at an angle; and then rotating the detection contact of the alignment mechanism so that the detection contact and the contact slide cover are both arranged horizontally toward the crystal ingot to be measured, and the contact slide cover is lower than the flat ground end surface of the crystal ingot to be measured; Preferably, the detection process includes: ensuring that the contact end of the contact slide of the alignment mechanism extends out of the detection surface, horizontally moving the alignment mechanism in a direction close to the crystal ingot to be measured until the contact slide touches the outer side wall of the crystal ingot to be measured, and stopping the horizontal movement of the alignment mechanism; rotating the supporting connecting arm of the alignment mechanism to drive the contact slide and the detection contact to move synchronously, so that the vertical spacing L1 from the contact end of the contact slide to the flat-ground end face of the crystal ingot to be measured satisfies 0.5mm≤L1≤1mm; then continuing to horizontally move the alignment mechanism in a direction close to the crystal ingot to be measured until the detection contact contacts the outer side wall of the crystal ingot to be measured, and using the detection component to collect the resistivity data of the flat-ground end face of the crystal ingot to be measured; Preferably, the resetting process includes: horizontally moving the alignment mechanism in a direction away from the crystal ingot to be measured to the end point of the path of the limiting groove, and rotating the detection contact so that the detection contact and the contact slide cover rotate synchronously until they are parallel to the supporting connecting arm, and then adjusting the supporting connecting arm so that it is arranged parallel to the bottom surface of the limiting groove and is in a storage state; then horizontally moving the alignment mechanism in the storage state again in a direction close to the crystal ingot to be measured to clear the relative displacement between the detection contact and the contact slide cover; Preferably, when the number of the alignment mechanisms is N, N≥2, and the single rotation angle of the movable guide rail is 0° to 360° / N.

9. The method for detecting flat grinding of silicon carbide ingot according to claim 8, characterized in that: The silicon carbide ingot flat grinding detection method further includes: before the detection, spraying a purge gas onto the flat grinding end surface of the ingot to be tested to purge and remove residual liquid.

10. A grinding device, characterized in that: The grinding device comprises the silicon carbide ingot flat grinding detection device according to any one of claims 1-6.

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