Wafer slip-out detection method for CMP equipment, controller and CMP equipment

Abstract

The invention is suitable for the technical field of semiconductor ultra-precision machining, and provides a CMP equipment wafer slip-out detection method, a controller and CMP equipment, the method is applied to the CMP equipment, and a spectral confocal sensor is arranged on a main shaft, where a grinding head is installed, of the CMP equipment. The spectral confocal sensor is used for detecting the real-time distance from the spectral confocal sensor to a grinding pad below the grinding head; the method comprises the steps that in the process that a grinding head adsorbs a wafer for grinding, if it is detected that the real-time distance from a spectral confocal sensor to a grinding pad is within a first distance range, it is judged that the wafer does not slide out; and if it is detected that the real-time distance from the spectral confocal sensor to the grinding pad exceeds the first distance range, it is judged that the wafer slides out. The problem that the detected wafer slides out can be solved, and the detection accuracy is improved.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor ultra-precision processing technology, and in particular, relates to a CMP equipment wafer slip detection method, a controller and a CMP equipment. Background Art

[0002] In the semiconductor manufacturing production process, the grinding unit of the Chemical Mechanical Polishing (CMP) equipment has a series of problems due to unreasonable pressure settings in various areas of the grinding head, which may cause the wafer to slip out of the grinding head during the grinding and polishing process. If there is no detection device after sliding out, the moving workpieces, such as the grinding head and grinding disk, fail to stop working immediately, which will cause the wafer to break and even damage the grinding head and other workpieces, destroying the chamber environment and causing great trouble for subsequent processing.

[0003] In the grinding unit of CMP equipment, the grinding head mainly carries the wafer and applies pressure to it, swinging it on the rotating grinding pad, and with the aid of grinding fluid, the wafer is ground and polished under the influence of chemical and mechanical effects to achieve full flatness. In order to prevent the wafer from slipping out of the grinding head, the existing method of detecting the wafer slipping out is to use optical detection, with a laser sensor and an amplifier installed on the upper side of the grinding head to detect the wafer slipping out. However, there is currently a problem of inaccurate detection using laser sensors, such as false detection caused by the laser emitted by the laser sensor hitting some reflective objects other than the wafer.

[0004] Therefore, it is necessary to find a method to solve the problem of wafer slipping detection and improve the accuracy of detection. Summary of the invention

[0005] In order to overcome the problems existing in the related art, the embodiments of the present application provide a CMP equipment wafer slip-out detection method, a controller and a CMP equipment, which can solve the problem of detecting wafer slip-out and improve the accuracy of detection.

[0006] This application is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a CMP device wafer slip-out detection method, which is applied to a CMP device, wherein a spectral confocal sensor is provided on a spindle of a CMP device for mounting a grinding head, and the spectral confocal sensor is used to detect a real-time distance from the spectral confocal sensor to a grinding pad under the grinding head; the method comprises:

[0008] During the process of the grinding head adsorbing the wafer for grinding, if the real-time distance from the spectral confocal sensor to the grinding pad is detected to be within the first distance range, it is judged that the wafer has not slipped out; if the real-time distance from the spectral confocal sensor to the grinding pad is detected to exceed the first distance range, it is judged that the wafer has slipped out.

[0009] In one embodiment, before the grinding head absorbs the wafer for grinding, when the grinding head moves above the wafer stage, the spectral confocal sensor is also used to detect a second distance from the spectral confocal sensor to the wafer stage below the grinding head;

[0010] The above method further includes:

[0011] Acquire a second distance from the spectral confocal sensor to the wafer stage when no wafer is placed;

[0012] Obtaining a third distance from the spectral confocal sensor to the upper surface of the wafer after the wafer is placed on the wafer stage; the thickness of the wafer is expressed as the difference between the second distance and the third distance;

[0013] If it is detected that the real-time distance from the spectral confocal sensor to the polishing pad exceeds the first distance range, it is determined that the wafer has slipped out, including:

[0014] If it is detected that the real-time distance from the spectral confocal sensor to the polishing pad exceeds the first distance range, it is detected whether the real-time distance from the spectral confocal sensor to the polishing pad is within a fourth distance range; if it is detected that the real-time distance from the spectral confocal sensor to the polishing pad is within the fourth distance range, it is determined that the wafer has slipped out; the fourth distance range = the first distance range - (the second distance - the third distance).

[0015] In one embodiment, obtaining a second distance from the spectral confocal sensor to the wafer stage when no wafer is placed includes:

[0016] Obtain the distances from the spectral confocal sensor to multiple positioning angles on the wafer stage when no wafer is placed;

[0017] An average value of the distances from the spectral confocal sensor to a plurality of positioning angles on the wafer stage is calculated as a second distance from the calibrated spectral confocal sensor to the wafer stage.

[0018] In one embodiment, the above method further includes:

[0019] When it is detected that a preset number of wafers are polished on the polishing pad, the polishing head is controlled to carry the wafers to rotate above the polishing pad, and the first distance range from the spectral confocal sensor to the polishing pad is re-acquired and updated.

[0020] In one embodiment, the first distance range is in, The first distance is preset, and D is the initial thickness of the wafer.

[0021] In one embodiment, after determining that the wafer has slipped out, the method further includes:

[0022] Send a stop signal to the machine host; the stop signal is used to control the polishing disc and polishing head to stop rotating, and the machine automatically stops operating.

[0023] In one embodiment, the material of the wafer is SiC, Si or GaN.

[0024] In one embodiment, the distance measurement range of the spectral confocal sensor is 30 mm to 150 mm; the thickness of the wafer is in the range of 300 μm to 1000 μm.

[0025] In a second aspect, an embodiment of the present application provides a controller for executing a CMP equipment wafer slip-out detection method as described in any one of the first aspects.

[0026] In a third aspect, an embodiment of the present application provides a CMP device, comprising a spectral confocal sensor and a controller as in the second aspect.

[0027] Compared with the related art, the embodiments of the present application have the following beneficial effects:

[0028] The embodiment of the present application detects whether the wafer has slipped out by measuring the distance, that is, the principle of height inconsistency when there is a wafer on the grinding disk or not. This is simple and accurate, and a spectral confocal sensor is set to detect wafer slippage. The spectral confocal sensor uses the wavelengths of reflected light of different colors to measure the distance, which is independent of the intensity of the reflected light. The intensity of the reflected light will not affect the measurement result. Therefore, no matter how much reflected light is reflected back from the object being measured, the measured distance result remains unchanged. This eliminates the detection failure caused by inconsistent light transmittance of wafers of different materials, solves the problem of detecting wafer slippage, and improves the accuracy of detection.

[0029] The beneficial effects of the second to third aspects mentioned above refer to the beneficial effects of the CMP equipment wafer slip-out detection method in the first aspect, which will not be repeated here.

[0030] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 This is a schematic diagram of the positions of various components during grinding of a CMP device provided in one embodiment of the present application;

[0033] Figure 2 This is a schematic diagram of the installation position of the spectral confocal sensor provided in one embodiment of the present application;

[0034] Figure 3 is a schematic diagram of the principle of a spectral confocal sensor provided in one embodiment of the present application;

[0035] Figure 4 It is a flow chart of a method for detecting a wafer slipping out of a CMP device provided in an embodiment of the present application;

[0036] Figure 5 is a schematic diagram of a second distance from the spectral confocal sensor to the wafer stage when no wafer is placed, provided by an embodiment of the present application;

[0037] Figure 6 It is a schematic diagram of obtaining a third distance from the spectral confocal sensor to the upper surface of the wafer after the wafer is placed on the wafer carrier according to an embodiment of the present application;

[0038] Figure 7 is a schematic diagram of the thickness of a wafer provided in an embodiment of the present application;

[0039] Figure 8 It is a schematic diagram of a flow chart of updating the distance from the sensor to the polishing pad provided in one embodiment of the present application. DETAILED DESCRIPTION

[0040] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0041] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0042] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0044] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] To prevent the wafer from slipping out of the grinding head, the existing method of detecting wafer slipping out is to use optical detection, and a laser sensor and an amplifier are installed on the upper side of the grinding head to detect wafer slipping out. The laser sensor emits laser light at one end, and when the laser hits an object that can reflect laser light, the receiving end can receive the reflected light signal, and then the reflected light signal is amplified by the amplifier, so as to judge by the characteristic changes of the reflected signal.

[0047] However, there are problems with optical detection of the third-generation semiconductor material silicon carbide wafer. First, the light transmittance of silicon carbide wafer is relatively strong. Compared with traditional silicon wafers, the change of light flux at the receiving end will be smaller, resulting in the inability to identify and detect. Second, silicon carbide wafers have inconsistent light transmittance due to factors such as production process, which makes them unrecognizable and undetectable. Therefore, the original detection method emits a single wavelength of light, and the light refracted by the wafer surface is collected, which cannot cover the detection of wafers of all materials.

[0048] Therefore, the present invention mainly adopts a ranging detection method to solve the problem of wafer slipping out during the grinding process. The wafer can cover substrates generated by all materials in the prior art and wafers in subsequent process steps, especially wafers of third-generation semiconductor materials with strong light transmittance such as silicon carbide and gallium nitride. Once the wafer slipping out is detected, the related workpieces can be set to stop working to protect the wafer from damage, or reduce the degree of wafer breakage to protect the workpiece, while reducing damage to the chamber environment and reducing the complexity of subsequent processing.

[0049] Figure 1This is a schematic diagram of the positions of various components during grinding of a CMP device provided in an embodiment of the present application. Figure 2 Schematic diagram of the installation position of the spectral confocal sensor, wherein the grinding head 100 of the CMP equipment absorbs the wafer 300 from the wafer carrier 400 and moves it to the grinding disc 200 for grinding. A grinding pad 201 is placed on the surface of the grinding disc, and the spindle 101 on which the grinding head is installed moves with the grinding head. Figure 1 and Figure 2 , the CMP equipment wafer slip detection method is described in detail as follows:

[0050] A CMP device wafer slip-out detection method is applied to the CMP device. A spectral confocal sensor 500 is provided on the main shaft of the CMP device for mounting a grinding head. The spectral confocal sensor is used to detect the real-time distance from the spectral confocal sensor to a grinding pad under the grinding head. The method comprises:

[0051] During the process of the grinding head adsorbing the wafer for grinding, if the real-time distance H1 from the spectral confocal sensor to the grinding pad is detected to be within the first distance range, it is judged that the wafer has not slipped out; if the real-time distance H1 from the spectral confocal sensor to the grinding pad is detected to exceed the first distance range, it is judged that the wafer has slipped out.

[0052] Among them, the first distance range is in, The first distance is preset, and D is the initial thickness of the wafer.

[0053] Exemplarily, the preset first distance may be the distance from the spectral confocal sensor to the polishing pad measured for the first time before the start of this polishing workflow, or the distance from the spectral confocal sensor to the polishing pad measured for the first time after a new polishing pad is installed.

[0054] For example, the spectral confocal sensor uses several special lenses to extend the focal halo range of different colors of light, decomposes the light according to the required range, forms special amplification chromatic aberration at different positions, and finally uses a convex lens to focus the light emitted by the sensor probe on an axis to form the so-called focal axis. Therefore, according to the distance from the object to the lens at different positions, a corresponding precise wavelength of light will be focused on the object to be measured. By measuring the wavelength λ of the reflected light, the precise distance from the object to the lens can be obtained, such as Figure 3 As shown. Figure 3 In the figure, S represents the white light point source of the spectral confocal sensor, λ o Represents the decomposed blue light and its wavelength, λ i Represents the decomposed yellow light and its wavelength, λ nIndicates the decomposed red light and its wavelength. Here, only the wavelength of light is calculated to generate the measurement signal, and the signal peak amplitude generated by the reflected light is not included in the signal measurement basis, that is, the intensity of the reflected light will not affect the measurement result, so no matter how much reflected light is reflected back from the measured object, the measured distance result remains unchanged. Because the intensity of the reflected light only depends on the reflective degree of the reflecting object. Even if the measured object is a strong light-absorbing material, such as black rubber or transparent material, normal and reliable measurements can be performed.

[0055] Exemplarily, a spectral confocal sensor that meets the designed range and accuracy can be selected. For example, the parameters of the spectral confocal sensor are a starting range of 100 mm, a linear measurement of 30 mm, an error within 7.5 μm, a weight of 700 g, and an allowable installation tilt angle.

[0056] For example, the inventors also considered that Si-based wafers can reflect lasers, but the rough surface of the polishing pad causes diffuse reflection and cannot reflect enough reflected light to the receiving end, resulting in a small reading of the amplifier, and it is not easy to detect the distance between the sensor and the polishing pad. Therefore, this embodiment uses a spectral confocal sensor to detect wafer slippage by distance measurement, which can not only eliminate detection failures caused by inconsistent light transmittance of wafers of different materials, but also eliminate false detections caused by reflective objects other than the wafer, such as foam that may be generated during grinding of the polishing liquid.

[0057] This embodiment uses distance measurement, that is, the principle of height inconsistency when there is a wafer on the grinding disk to detect whether the wafer has slipped out or an abnormal object has appeared on the grinding disk to interfere with normal grinding. It is simple and accurate, and a spectral confocal sensor is set to detect wafer slippage. The spectral confocal sensor uses the wavelengths of reflected light of different colors to measure the distance, which is independent of the intensity of the reflected light. The intensity of the reflected light will not affect the measurement result. Therefore, no matter how much reflected light is reflected back from the measured object, the measured distance result remains unchanged. This eliminates detection failures caused by inconsistent light transmittance of wafers of different materials and false detections caused by reflective objects other than the wafer. While solving the problem of detecting wafer slippage, it also improves detection accuracy.

[0058] An embodiment, different from the above embodiment which detects whether the real-time distance H1 from the spectral confocal sensor to the polishing pad exceeds the first distance range, this embodiment can provide a more accurate judgment condition whether the real-time distance H1 from the spectral confocal sensor to the polishing pad exceeds the first distance range.

[0059] Before the grinding head absorbs the wafer for grinding, when the grinding head moves above the wafer stage, the spectral confocal sensor is also used to detect a second distance from the spectral confocal sensor to the wafer stage below the grinding head.

[0060] See also Figure 4, the CMP equipment wafer slip detection method also includes:

[0061] S1: Acquire a second distance H2 from the spectral confocal sensor to the wafer stage when no wafer is placed.

[0062] For example, in order to obtain a more accurate second distance H2, the distance from the spectral confocal sensor to the wafer stage is obtained when no wafer is placed on the wafer stage, such as Figure 5 As shown, the second distance H2 is zero-calibrated, that is, S1 includes:

[0063] The distances from the spectral confocal sensor to multiple positioning angles on the wafer stage when no wafer is placed are obtained. For example, the distances from the spectral confocal sensor to the five positioning angles can be obtained. That is, the distances from the spectral confocal sensor to the multiple positioning angles on the wafer stage are multiple second distances.

[0064] The average value of the distances from the spectral confocal sensor to the wafer stage at multiple positioning angles is calculated as the second distance H2 from the spectral confocal sensor to the wafer stage. In this step, the second distance is zero-calibrated by averaging.

[0065] S2: Obtain a third distance H3 from the spectral confocal sensor to the upper surface of the wafer after the wafer is placed on the wafer stage.

[0066] Exemplarily, in order to be compatible with wafers of different thicknesses, after the wafer is placed on the wafer stage, a third distance H3 from the spectral confocal sensor to the upper surface of the wafer is obtained, such as Figure 6 As shown, then, the second distance H2 and the third distance H3 are obtained, and the thickness of the wafer can be directly output. The thickness of the wafer is expressed as the difference between the second distance H2 and the third distance H3, such as Figure 7 shown.

[0067] Based on the above steps S1 and S2, S3 can be continued: obtaining the real-time distance from the spectral confocal sensor to the grinding pad under the grinding head. Based on the above steps S1, S2 and S3, a more accurate judgment condition is given that the real-time distance H1 from the spectral confocal sensor to the grinding pad exceeds the first distance range. Then, if it is detected that the real-time distance from the spectral confocal sensor to the grinding pad exceeds the first distance range, it is judged that the wafer has slipped out, including:

[0068] S4: If it is detected that the real-time distance from the spectral confocal sensor to the polishing pad exceeds the first distance range, continue to determine whether the real-time distance from the spectral confocal sensor to the polishing pad is within a fourth distance range; if it is detected that the real-time distance from the spectral confocal sensor to the polishing pad is within the fourth distance range, determine that the wafer has slipped out.

[0069] The fourth distance range is smaller than the first distance range. The fourth distance range = the first distance range - (H2 - H3). The allowable error of the fourth distance range is ±10% of the initial thickness D of the wafer, that is, the fourth distance range can be expressed as

[0070] This embodiment uses zero-point calibration to confirm the distance from the sensor to the upper surface of the wafer, and then combines the height from the sensor to the polishing pad, and uses the relationship between H1, H2 and H3 to obtain the design method of the wafer slip-out judgment condition, so as to further accurately judge the wafer slip-out and reduce misjudgment.

[0071] In one embodiment, considering that the polishing pad is consumed over time, the distance from the sensor to the polishing pad is updated once when the polishing head carrying the wafer rotates above the polishing pad.

[0072] See also Figure 8 In the process of grinding by the grinding head adsorbing the wafer, the CMP equipment wafer slip detection method also includes:

[0073] S5: When it is detected that a preset number of wafers are polished on the polishing pad, the polishing head is controlled to carry the wafers to move above the polishing pad, and the first distance range from the spectral confocal sensor to the polishing pad is reacquired and updated.

[0074] Exemplarily, since the first distance range is Therefore, the preset first distance from the spectral confocal sensor to the polishing pad is remeasured here. The step S5 may be arranged between the step S3 and the step S4 in the above embodiment, and the step S4 uses the updated first distance range to form the wafer slip-out judgment condition.

[0075] Exemplarily, the preset number can be set to 50. In this embodiment, when the number of wafers ground by the grinding pad increases to 50, the grinding pad will be significantly worn, which will have a certain impact on the detection distance. The grinding head then carries the wafer to the top of the grinding pad and updates the distance from the sensor to the grinding pad.

[0076] This embodiment takes into account that as the polishing pad is used, its surface will gradually wear, causing the originally set distance between the sensor and the polishing pad to change. If this distance range is not adjusted in time, it may cause false positives or missed positives in wafer slip detection. By regularly updating this distance range, the accuracy of the detection system can be ensured and errors caused by wear can be reduced.

[0077] In one embodiment, after determining that the wafer has slipped out, the CMP equipment wafer slip-out detection method further includes:

[0078] Send a stop signal to the machine host; the stop signal is used to control the polishing disc and polishing head to stop rotating, and the machine automatically stops operating.

[0079] During the polishing process, the distance change is continuously monitored. If the polishing disc and polishing head continue to rotate after the wafer slips out, it may cause further friction and collision between the wafer and the equipment, resulting in physical damage to the wafer or wear of equipment components. Immediate shutdown can avoid this unnecessary damage and protect the integrity of the wafer and equipment. By automatically sending a shutdown signal and controlling the equipment to shut down, automated monitoring and fault handling of the wafer processing process are achieved. This helps to improve the automation level of the entire production line, reduce the need for manual intervention, and improve production efficiency and stability.

[0080] Exemplarily, the material of the wafer may be SiC, Si or GaN. The method of the above embodiment is suitable for all CMP machines, and is compatible with different models such as 6 / 8 / 12 inches, and wafers of different materials and thicknesses such as SiC / Si / GaN.

[0081] Illustratively, in each embodiment of the present application, the spectral confocal sensor emits white light, and the distance measurement range of the spectral confocal sensor is 30 mm to 150 mm; the thickness of the wafer ranges from 300 μm to 1000 μm.

[0082] Exemplarily, the distance from the spectral confocal sensor to the wafer stage is in the range of 30 to 150 mm, the distance from the spectral confocal sensor to the upper surface of the wafer is in the range of 30 to 150 mm, and the distance from the spectral confocal sensor to the polishing pad is in the range of 30 mm to 150 mm.

[0083] The wafer slip detection method of the CMP equipment of the embodiment of the present application uses the distance measurement method, that is, the height difference when there is a wafer on the grinding disc to detect the wafer slip, and at the same time eliminates the detection failure caused by the inconsistent light transmittance of wafers of different materials, and the false detection caused by reflective objects other than the wafer, such as the light of the end point detection and the foam that may be generated during the grinding of the grinding liquid. Secondly, it can realize multiple uses of one object, and only one spectral confocal sensor can simultaneously detect wafer slip, wafer thickness, and grinding pad loss, so the grinding pad roughness detection can also be realized when the grinding pad is lost.

[0084] It should be understood that the execution order of the above processes should be determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In order to reduce the complexity of the patent description, the present invention provides a detection method involved in the detection method of wafer slipping out of a compound CMP device, and the sensor types used and the calculation process are all included in the protection scope of this patent.

[0085] Of course, the number of spectral confocal sensors in this application is given as one example, which is the simplest and lowest-cost implementation method. If the number of spectral confocal sensors is expanded to 2, 3, or other numbers with reference to the aforementioned embodiments, it is still within the protection scope of this application.

[0086] It should be noted that the information interaction, execution process and other contents between the above-mentioned devices are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0087] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0088] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A CMP equipment wafer slip detection method, characterized in that: Applied to a CMP device, a spectral confocal sensor is provided on the main shaft of the CMP device for mounting a grinding head, and the spectral confocal sensor is used to detect the real-time distance from the spectral confocal sensor to the grinding pad under the grinding head; the method comprises: During the process of the grinding head adsorbing the wafer for grinding, if it is detected that the real-time distance from the spectral confocal sensor to the grinding pad is within a first distance range, it is judged that the wafer has not slipped out; if it is detected that the real-time distance from the spectral confocal sensor to the grinding pad exceeds the first distance range, it is judged that the wafer has slipped out.

2. The CMP equipment wafer slip detection method according to claim 1, characterized in that: Before the grinding head absorbs the wafer for grinding, when the grinding head moves above the wafer stage, the spectral confocal sensor is also used to detect a second distance from the spectral confocal sensor to the wafer stage below the grinding head; The method further comprises: Acquire a second distance from the spectral confocal sensor to the wafer stage when no wafer is placed; Acquiring a third distance from the spectral confocal sensor to the upper surface of the wafer after the wafer is placed on the wafer stage; the thickness of the wafer is expressed as a difference between the second distance and the third distance; If it is detected that the real-time distance from the spectral confocal sensor to the polishing pad exceeds the first distance range, determining that the wafer has slipped out includes: If it is detected that the real-time distance from the spectral confocal sensor to the polishing pad exceeds the first distance range, it is detected whether the real-time distance from the spectral confocal sensor to the polishing pad is within a fourth distance range; if it is detected that the real-time distance from the spectral confocal sensor to the polishing pad is within the fourth distance range, it is determined that the wafer has slipped out; the fourth distance range = the first distance range - (the second distance - the third distance).

3. The CMP equipment wafer slip detection method according to claim 2, characterized in that: The obtaining of a second distance from the spectral confocal sensor to the wafer stage when no wafer is placed includes: Acquiring the distances from the spectral confocal sensor to multiple positioning angles on the wafer stage when no wafer is placed; An average value of distances from the spectral confocal sensor to a plurality of positioning angles on the wafer stage is calculated as a second distance from the spectral confocal sensor to the wafer stage.

4. The CMP equipment wafer slip detection method according to claim 1, characterized in that: The method further comprises: When it is detected that a preset number of wafers are polished on the polishing pad, the polishing head is controlled to carry the wafers to rotate above the polishing pad, and the first distance range from the spectral confocal sensor to the polishing pad is re-acquired and updated.

5. The CMP equipment wafer slip detection method according to any one of claims 1 to 4, characterized in that: The first distance range is in, The first distance is preset, and D is the initial thickness of the wafer.

6. The CMP equipment wafer slip detection method according to any one of claims 1 to 4, characterized in that: After determining that the wafer has slipped out, the method further includes: Send a stop signal to the machine host; the stop signal is used to control the polishing disc and the polishing head to stop rotating, and the machine automatically stops operating.

7. The CMP equipment wafer slip detection method according to any one of claims 1 to 4, characterized in that: The material of the wafer is SiC, Si or GaN.

8. The CMP equipment wafer slip detection method according to any one of claims 1 to 4, characterized in that: The distance measurement range of the spectral confocal sensor is 30 mm to 150 mm; the thickness of the wafer is in the range of 300 μm to 1000 μm.

9. A controller, characterized in that: Used to execute the CMP equipment wafer slip-out detection method as described in any one of claims 1 to 8.

10. A CMP device, characterized in that: It comprises a spectral confocal sensor and a controller as claimed in claim 9.

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