Silicon wafer polishing method and silicon wafer polishing apparatus

Abstract

The application provides a silicon wafer polishing method and a silicon wafer polishing device. The template assembly of the silicon wafer polishing device comprises a film base and a ring part extending from the edge of the film base to form a groove for holding a silicon wafer. The ring part is provided with a telescopic unit. The method comprises the following steps: detecting the wear stress of the ring part during the polishing process of the silicon wafer to obtain stress data; and adjusting the length of the telescopic unit to change the depth of the groove when the stress data is not within a target value range. By monitoring the wear stress of the ring part and automatically adjusting the length of the telescopic unit, the automatic adjustment of the TA size is realized, the automation level and the utilization rate of the device are improved, the excessive wear of the TA caused by excessive wear stress can be effectively reduced, and the service life of the TA is prolonged. In addition, the automatic regulation of the TA size can ensure that the removal amount of the edge of the silicon wafer is at a reasonable level, and the edge flatness of the silicon wafer and the product quality are improved.

Description

Technical Field

[0001] This application relates to the field of silicon wafer polishing technology, and more particularly to silicon wafer polishing methods and equipment. Background Technology

[0002] In semiconductor manufacturing, silicon wafer polishing is a crucial step in ensuring the flatness of the silicon wafer surface. High-quality polishing can effectively remove minute imperfections on the silicon wafer surface, improving the accuracy and efficiency of subsequent processes. Related silicon wafer polishing equipment typically uses fixed-size template assemblies (TAs) to fix and hold the silicon wafer in position during the polishing process.

[0003] However, since the TA (Transformer Atomizer) has a fixed size, different sizes of TA are often required depending on the processing conditions. This process usually requires manual intervention, which not only increases the complexity and time cost of operation but also reduces equipment uptime. Secondly, a larger TA size may lead to a reduction in the amount of material removed from the silicon wafer edges, thus affecting the edge flatness of the silicon wafer.

[0004] Based on this, this application provides a silicon wafer polishing method and silicon wafer polishing equipment to improve related technologies. Summary of the Invention

[0005] The purpose of this application is to provide a silicon wafer polishing method and silicon wafer polishing equipment, which realizes automatic adjustment of TA size, improves the automation level and utilization rate of the equipment, and enhances the edge flatness of the silicon wafer.

[0006] The objective of this application is achieved through the following technical solution:

[0007] In a first aspect, this application provides a silicon wafer polishing method. The template assembly of the silicon wafer polishing equipment includes a thin film base and a ring portion. The ring portion extends from the edge of the thin film base to form a groove for holding the silicon wafer. The ring portion is provided with a telescopic unit. The method includes: during the polishing process of the silicon wafer, detecting the wear stress of the ring portion to obtain stress data; and if the stress data is not within a target value range, adjusting the length of the telescopic unit to change the depth of the groove.

[0008] In some embodiments, adjusting the length of the telescopic unit when the stress data is not within the target value range includes: reducing the length of the telescopic unit to reduce the depth of the groove when the stress data is greater than the maximum value of the target value range.

[0009] In some embodiments, the method further comprises: calculating a target length of the telescopic unit by using an edge flatness automation model before polishing the silicon wafer; and controlling the length of the telescopic unit to be the target length.

[0010] In some embodiments, the method further comprises: receiving actual edge flatness data of the silicon wafer; and updating model parameters of the edge flatness automation model by using the actual edge flatness data.

[0011] In some embodiments, the input data of the edge flatness automation model comprises size data of the template assembly, life data, and target edge flatness data of the silicon wafer.

[0012] In some embodiments, the method further comprises: measuring the depth of the groove before polishing the silicon wafer.

[0013] In some embodiments, the method further comprises: performing an alarm operation in the case that the stress data is not within the target numerical range.

[0014] In a second aspect, the present application provides a silicon wafer polishing device, comprising: a template assembly comprising a film base and a ring part, the ring part extending from the edge of the film base to form a groove for holding a silicon wafer, the ring part being provided with a telescopic unit; a pressure sensor for detecting the wear stress of the ring part during the polishing of the silicon wafer to obtain stress data; and a control module for adjusting the length of the telescopic unit to change the depth of the groove in the case that the stress data is not within a target numerical range.

[0015] In some embodiments, the silicon wafer polishing device further comprises: a polishing disc; a polishing head; a chuck between the polishing head and the template assembly, the chuck being used to connect the polishing head and the template assembly; a pressure assembly for creating a negative pressure environment between the polishing head and the polishing disc to adsorb the silicon wafer, or creating a positive pressure environment between the polishing head and the polishing disc to press the silicon wafer.

[0016] In some embodiments, the telescopic unit comprises one or more telescopic rods; the pressure sensor is close to the end of the telescopic unit away from the polishing head; and the silicon wafer polishing device further comprises a distance measuring sensor, the distance measuring sensor being arranged on the surface of the film base away from the polishing head, and the distance measuring sensor being used to measure the depth of the groove before polishing the silicon wafer.

[0017] In some embodiments, the control module stores an edge flatness automation model; input data of the edge flatness automation model includes size data of the template assembly, service life data, and target edge flatness data of the silicon wafer.

[0018] The present application provides a silicon wafer polishing method and a silicon wafer polishing device. The template assembly of the silicon wafer polishing device includes a film base and a ring part extending from the edge of the film base, thereby forming a groove for fixing and holding the silicon wafer. The ring part is provided with a telescopic unit for dynamically adjusting the depth of the groove. During the polishing process, stress data is obtained by detecting the wear stress of the ring part. When the detected wear stress is not within the preset target value range, the length of the telescopic unit is automatically adjusted, thereby changing the depth of the groove. By monitoring the wear stress of the ring part and automatically adjusting the length of the telescopic unit, the TA size is automatically adjusted, the need for manual operation is reduced, and the automation level and the utilization rate of the device are improved. Based on the TA size automatic regulation and control based on the wear stress, the excessive wear of the TA caused by excessive wear stress can be effectively reduced, the service life of the TA is prolonged, and the maintenance and replacement costs are reduced. In addition, the automatic regulation and control of the TA size can ensure that the removal amount of the edge of the silicon wafer is at a reasonable level, and the edge flatness and product quality of the silicon wafer are improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 is a front view of a silicon wafer polishing device provided by an embodiment of the present application.

[0021] Figure 2 is a schematic view of a silicon wafer being polished by a silicon wafer polishing device provided by an embodiment of the present application.

[0022] Figure 3 is an application flowchart of an edge flatness automation model provided by an embodiment of the present application.

[0023] In the figure: 101, polishing disc; 102, polishing head; 103, pressure assembly; 104, chuck; 105, template assembly; 106, telescopic unit; 107, pressure sensor; 108, distance sensor; 201, silicon wafer; 301, film base; 302, ring part; 303, groove. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the description of the embodiments of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Currently, the polishing head of the final polishing equipment uses TA (Template Assemble) to fix the silicon wafer. However, different sizes of TA need to be replaced depending on the different processing conditions. If the TA size is too large, it will reduce the amount of silicon wafer edge removal.

[0027] See Figure 1 and Figure 2 , Figure 1 This is a front view of a silicon wafer polishing apparatus provided in an embodiment of this application. Figure 2 This is a schematic diagram of a silicon wafer polishing device provided in an embodiment of this application polishing a silicon wafer 201.

[0028] This application provides a method for polishing a silicon wafer 201. The template assembly 105 of the silicon wafer polishing equipment includes a thin film base 301 and a ring portion 302. The ring portion 302 extends from the edge of the thin film base 301 to form a groove 303 for holding the silicon wafer 201. The ring portion 302 is provided with a telescopic unit 106. The method includes: during the polishing process of the silicon wafer 201, detecting the wear stress of the ring portion 302 to obtain stress data; if the stress data is not within the target value range, adjusting the length of the telescopic unit 106 to change the depth of the groove 303.

[0029] In the above embodiments, adjusting the length of the telescopic unit 106 can be done by automatically increasing the length of the telescopic unit 106 to increase the depth of the groove 303, or by automatically decreasing the length of the telescopic unit 106 to decrease the depth of the groove 303.

[0030] In some embodiments, the adjusting the length of the telescopic unit 106 in the case that the stress data is not within the target value range can include: in the case that the stress data is greater than the maximum value of the target value range, reducing the length of the telescopic unit 106 to reduce the depth of the groove 303.

[0031] The above method has high automation, specifically, the TA size is automatically controlled, the personnel replacement is reduced, and the equipment utilization rate is improved. In addition, the service life of spare parts (for example, TA spare parts) can be improved, the TA size is automatically adjusted in the case that there is a special situation (for example, the stress data is not within the target value range), the TA wear is reduced, and the TA service life is prolonged. The TA size is automatically adjusted, the removal amount of the edge of the silicon wafer 201 can be guaranteed to be at a reasonable level, and the edge flatness of the silicon wafer 201 and the product quality are improved. The utilization rate refers to the proportion of time occupied by the equipment in order to create value within the time that can be provided. The spare part is also called a maintenance part, which is a replaceable part in stock, and is used when a device needs to be repaired, maintained or renewed.

[0032] Referring to Figure 3 , Figure 3 is a schematic diagram of an application flow of an edge flatness automatic model provided by an embodiment of the present application.

[0033] In some embodiments, the method can further include: calculating a target length of the telescopic unit 106 by using the edge flatness automatic model before polishing the silicon wafer 201; and controlling the length of the telescopic unit 106 to be the target length.

[0034] In some embodiments, the method can further include: receiving actual edge flatness data of the silicon wafer 201; and updating model parameters of the edge flatness automatic model by using the actual edge flatness data. As an example, the actual edge flatness data of the silicon wafer 201 can be detected by using a silicon wafer surface flatness detection device after polishing the silicon wafer 201.

[0035] In some embodiments, the input data of the automated edge flatness model may include the size data and lifetime data of the template assembly 105, and the target edge flatness data of the silicon wafer 201. The size data of the template assembly 105 may, for example, include the depth of the groove 303. As an example, before polishing the silicon wafer 201, the size data and lifetime data of the template assembly 105, and the target edge flatness data of the silicon wafer 201 are input into the automated edge flatness model. The automated edge flatness model is used to perform simulation calculations to obtain the target length of the telescopic unit 106. The length of the telescopic unit 106 is controlled to the simulated length (i.e., the target length) before the polishing operation of the silicon wafer 201 is performed.

[0036] The above embodiments are beneficial for improving the flatness of silicon wafer 201. Specifically, an automated edge flatness model is established to control the length of the telescopic unit 106, which effectively ensures the flatness of the processed silicon wafer 201.

[0037] like Figure 3 As shown, in a specific application scenario, the system (e.g., a silicon wafer polishing device) establishes a preliminary model of ESFQR parameters (i.e., an automated edge flatness model); then, before polishing the silicon wafer 201, the TA dimensions (i.e., the size data of the template assembly 105, such as including the depth of the groove 303), lifetime (i.e., the lifetime data of the template assembly 105), and ESFQR parameters (here, the target edge flatness data of the silicon wafer 201) are imported into the model (i.e., the automated edge flatness model); next, the automated edge flatness model is used for simulation calculation. The target length of the telescopic unit 106 (e.g., including one or more telescopic rods) is calculated and executed, that is, the length of the telescopic unit 106 is controlled to the simulated calculated length (i.e., the target length). Afterwards, data (e.g., actual edge flatness data of the silicon wafer 201) can be continuously collected and the model (i.e., the automated edge flatness model) can be improved. Improving the model, for example, means updating the model parameters to optimize the subsequently calculated target length of the telescopic unit 106, thereby dynamically controlling the ESFQR parameters (here, the actual edge flatness data of the silicon wafer 201). ESFQR stands for Edge Site Front Quotient Range, also known as edge flatness or local edge flatness.

[0038] In some embodiments, the method can further include: measuring the depth of the groove 303 before polishing the silicon wafer 201. After measuring the depth of the groove 303, the measured data can be recorded, so as to not only realize automatic control of the TA size, but also realize automatic recording of related data (for example, the depth of the groove 303). Wherein, the automatic control of the TA size is realized by adjusting the length of the telescopic unit 106.

[0039] In some embodiments, the method can further include: in the case that the stress data is not in the target value range, performing an alarm operation. Wherein, the alarm operation may, for example, include one or more of a voice alarm operation, a light alarm operation, and an alarm information pushing operation, and the alarm information pushing operation may, for example, push alarm information to a terminal device (for example, a mobile phone, a tablet computer, a desktop computer, a wearable device, etc.) of a relevant worker. Thus, it is convenient for the worker to timely handle the case that the stress data is not in the target value range in the silicon wafer polishing process, reduce TA wear, and prolong the TA life.

[0040] Compared with related technologies, the above-mentioned embodiments design a TA size automatic control function, reduce manual replacement, and improve the utilization rate of the equipment. Due to the automatic control of the TA size, the TA life can be prolonged when the grinding stress is too large. An ESFQR control model (that is, an edge flatness automatic model) is established, and model parameters are updated according to detection data (for example, actual edge flatness data), so as to automatically control the TA size and effectively improve the flatness (for example, the edge flatness) of the silicon wafer 201. In general, the above-mentioned embodiments realize the improvement of the utilization rate of the silicon wafer polishing equipment (for example, the final polishing equipment), prolong the TA life, and improve the flatness level of the silicon wafer 201.

[0041] The embodiments of the present application also provide a silicon wafer polishing equipment, which includes a template assembly 105, a pressure sensor 107, and a control module. The template assembly 105 includes a film base 301 and a ring part 302 extending from the edge of the film base 301 to form a groove 303 for holding a silicon wafer 201, and the ring part 302 is provided with a telescopic unit 106. The pressure sensor 107 is used to detect the wear stress of the ring part 302 during the polishing process of the silicon wafer 201 to obtain stress data. The control module is used to adjust the length of the telescopic unit 106 to change the depth of the groove 303 in the case that the stress data is not in a target value range.

[0042] In some embodiments, the silicon wafer polishing apparatus can further comprise a polishing plate 101, a polishing head 102, a chuck 104, and a pressure assembly 103. The chuck 104 is located between the polishing head 102 and the template assembly 105, and is used to connect the polishing head 102 and the template assembly 105. The pressure assembly 103 is used to create a negative pressure environment between the polishing head 102 and the polishing plate 101 to adsorb the silicon wafer 201, or to create a positive pressure environment between the polishing head 102 and the polishing plate 101 to press the silicon wafer 201.

[0043] The material of the chuck 104 is not limited in the above embodiments. In some embodiments, the chuck 104 can be a rubber chuck 104.

[0044] In some embodiments, the telescopic unit 106 can comprise one or more telescopic rods.

[0045] In some embodiments, the pressure sensor 107 can be located close to the end of the telescopic unit 106 that is away from the polishing head 102.

[0046] In some embodiments, the silicon wafer polishing apparatus can further comprise a distance measuring sensor 108, which is disposed on the surface of the film base 301 that is away from the polishing head 102. The distance measuring sensor 108 is used to measure the depth of the recess 303 before polishing the silicon wafer 201. As an example, before polishing the silicon wafer 201, the control TA is moved downward until the TA just contacts the polishing plate 101. The distance measuring sensor 108 measures the distance between the location and the polishing plate 101 as the depth of the recess 303.

[0047] For example, as shown in FIG. 1, the distance measuring sensor 108 is disposed on the surface of the film base 301 that is away from the polishing head 102. Figure 1 and Figure 2As shown, the silicon wafer 201 is adsorbed by the polishing head 102 through the pressure assembly 103, in which the chuck 104 is used to connect the TA, and the telescopic unit 106 includes a plurality of telescopic rods. Before the polishing is started, the pressure assembly 103 uses negative pressure (i.e., a negative pressure environment is created). After the polishing is started, the pressure assembly 103 uses positive pressure (i.e., a positive pressure environment is created) to press the silicon wafer 201 onto the polishing disc 101 for polishing, and at the same time, the TA will be in contact with the polishing disc 101 to cause wear due to the positive pressure. When a special situation occurs, for example, the wear stress exceeds the upper threshold value (i.e., the maximum value of the target value range) of the target value range, the length of the telescopic rod is automatically adjusted (for example, the telescopic rod is automatically retracted) to ensure that the TA is not worn by high intensity, and at the same time, the device alarms to inform the personnel to check the abnormality. After collecting the ESFQR data (for example, the actual edge flatness data) of the device, the telescopic rod will automatically adjust the depth of the TA groove (i.e., the recess 303) to ensure the quality of the subsequent processing products, and the current TA groove depth is automatically measured by the distance sensor 108 before processing and recorded to facilitate subsequent data analysis.

[0048] In some embodiments, the control module can store an edge flatness automation model; the input data of the edge flatness automation model includes the size data of the template assembly 105, the service life data, and the target edge flatness data of the silicon wafer 201.

[0049] The above embodiments can be widely applied in the fields of semiconductor manufacturing, final polishing technology, etc. First, the TA size of the polishing head 102 is automatically controlled, which reduces personnel replacement and improves the utilization rate of the device; second, the threshold value (for example, the upper threshold value and the lower threshold value of the target value range) is set to prolong the service life of the TA; and finally, the edge flatness automation model is established to improve the overall flatness level of the silicon wafer 201. The above-mentioned silicon wafer polishing device has great market demand, especially in large-scale semiconductor manufacturing enterprises, and is expected to realize the automation and intelligentization of the silicon wafer polishing device (for example, the final polishing device), greatly improve the production efficiency, and reduce the production cost.

[0050] It should be noted that each of the embodiments in the present application is described in a progressive manner, and the same or similar parts of each embodiment can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for product embodiments, since they are basically similar to method embodiments, they are described more simply, and the relevant parts can be referred to the part of the method embodiment.

[0051] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first", "second", and the like, as used in the present disclosure, do not imply any order, quantity, or importance, but are used to distinguish different components. The terms "include", "comprise", and the like, mean to encompass the elements listed after such terms and equivalents thereof, and do not exclude other elements. The terms "connected", "coupled", and the like, do not necessarily mean physically or mechanically connected, but can include electrical connection, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like, are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0052] It can be understood that when an element such as a layer, a film, a region, or a substrate is referred to as being "on" or "under" another element, it can be "directly" on or under the other element, or an intervening element can also be present.

[0053] In the description of the above-described embodiments, specific features, structures, materials, or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0054] The above description is merely illustrative of the disclosure and does not limit the scope of the disclosure. Any modifications made within the scope of the disclosure disclosed herein should be encompassed by the scope of the disclosure. Therefore, the scope of the disclosure should be based on the scope of the claims.

Claims

1. A method for polishing silicon wafers, characterized in that, The template assembly of the silicon wafer polishing equipment includes a thin film base and a ring portion, the ring portion extending from the edge of the thin film base to form a groove for holding the silicon wafer, the ring portion being provided with a telescopic unit, the method comprising: During the polishing process of the silicon wafer, the wear stress of the ring is detected to obtain stress data; If the stress data is not within the target value range, adjust the length of the telescopic unit to change the depth of the groove; The method further includes: calculating the target length of the telescopic unit using an automated edge flatness model before polishing the silicon wafer; controlling the length of the telescopic unit to the target length; the input data of the automated edge flatness model includes the size data and lifetime data of the template assembly and the target edge flatness data of the silicon wafer; The method further includes: receiving actual edge flatness data of the silicon wafer; and using the actual edge flatness data to update the model parameters of the automated edge flatness model.

2. The silicon wafer polishing method according to claim 1, characterized in that, Adjusting the length of the telescopic unit when the stress data is not within the target value range includes: If the stress data is greater than the maximum value of the target value range, the length of the telescopic unit is reduced to reduce the depth of the groove.

3. The silicon wafer polishing method according to claim 1, characterized in that, The method further includes: Before polishing the silicon wafer, the depth of the groove is measured; and / or, If the stress data is not within the target value range, an alarm operation is performed.

4. A silicon wafer polishing device, characterized in that, The silicon wafer polishing equipment includes: A template assembly includes a thin film base and a ring portion, the ring portion extending from the edge of the thin film base to form a groove for holding a silicon wafer, the ring portion being provided with a telescopic unit; A pressure sensor is used to detect the wear stress of the ring during the polishing process of the silicon wafer in order to obtain stress data; The control module is configured to adjust the length of the telescopic unit to change the depth of the groove when the stress data is not within the target value range; calculate the target length of the telescopic unit using an automated edge flatness model before polishing the silicon wafer; control the length of the telescopic unit to the target length; and receive the actual edge flatness data of the silicon wafer; and update the model parameters of the automated edge flatness model using the actual edge flatness data. The input data for the automated edge flatness model includes the size data and lifetime data of the template component, as well as the target edge flatness data of the silicon wafer.

5. The silicon wafer polishing equipment according to claim 4, characterized in that, The silicon wafer polishing equipment also includes: Polishing disc; Polishing head; A chuck is located between the polishing head and the template assembly, and the chuck is used to connect the polishing head and the template assembly; A pressure assembly is used to create a negative pressure environment between the polishing head and the polishing disk to adsorb the silicon wafer; or, to create a positive pressure environment between the polishing head and the polishing disk to compress the silicon wafer.

6. The silicon wafer polishing equipment according to claim 5, characterized in that, The telescopic unit includes one or more telescopic rods; The pressure sensor is located near the end of the telescopic unit that is furthest from the polishing head; The silicon wafer polishing equipment also includes a distance sensor disposed on the surface of the thin film substrate away from the polishing head. The distance sensor is used to measure the depth of the groove before polishing the silicon wafer.

7. The silicon wafer polishing equipment according to claim 4, characterized in that, The control module stores an automated model of edge flatness.

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