Chemical mechanical polishing method and device and storage medium

Abstract

The invention discloses a chemical mechanical polishing method and device and a storage medium. Polishing equipment is controlled to pre-grind a residual layer of a semiconductor structure until the thickness of the residual layer meets a preset thickness condition; and controlling the polishing equipment to perform secondary grinding on the residual layer meeting the preset thickness condition, and detecting end point detection data in the secondary grinding process until the end point detection data indicates that a grinding end point is reached, thereby obtaining a target semiconductor structure. According to the method, the semiconductor structure to be polished is pre-ground until the thickness of the residual layer meets the preset thickness condition, so that the specified thickness is provided for the subsequent secondary grinding stage, the window of the grinding end point in the end point detection data can be expanded when the end point detection data is detected in the secondary grinding process, and the grinding efficiency is improved. And the accuracy, reliability and stability of grabbing the grinding end point are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor process technology, and in particular to a chemical mechanical polishing method, device and storage medium. Background Art

[0002] Shallow Trench Isolation CMP (STI CMP) is a technology that uses an oxide layer to separate each gate circuit (CATE) so that each gate circuit is not connected to each other. The key to STI CMP technology is to accurately control the polishing process to ensure that the silicon wafer surface around the trench is flat while avoiding damage to the insulating material in the trench, which helps to improve the performance of integrated circuits, reduce crosstalk between transistors, and improve chip reliability and yield. Therefore, it is important to accurately grind to the point where it should stop, so as to avoid over-grinding or removing too little. The point where grinding should stop is called CMP grinding end point detection EPD (End Point Detection).

[0003] In the conventional STI CMP process, in addition to setting a fixed number of grinding seconds, the motor current detection method is often used to determine the STI grinding endpoint. However, in the current process, due to the difference in consumables in the polishing equipment, such as the type of polishing pad, the state of the polishing pad and the polishing disk, as well as the difference in the operating stability of the polishing equipment itself, such as the dynamic changes in pressure, rotation speed and scanning speed, the polishing speed and polishing time in the polishing process change. At the same time, there are thickness fluctuations between different semiconductor structures to be polished, and the characteristics of the grinding endpoint detection system itself, such as high delay in capturing the grinding endpoint signal, short window of the grinding endpoint signal that is difficult to identify, and many interference factors, which are easy to cause the polishing time to change during the polishing process. The fluctuation of polishing time and polishing pressure is not conducive to the accuracy of the polishing process. In addition, the thickness of the semiconductor structure to be polished is generally thick, and direct polishing is more likely to make it difficult to capture the grinding endpoint signal in the later stage, thereby causing the semiconductor structure to have residues or over-grinding, which is not conducive to the accuracy of the polishing process, affecting the product yield of the semiconductor structure, and also affecting the function of the semiconductor structure, resulting in waste of production capacity. The workload required for manual control is huge, the manpower cost is high, and it takes too long. Summary of the invention

[0004] In order to solve the problems of the prior art, the embodiments of the present application provide a chemical mechanical polishing method, device and storage medium. The technical solution is as follows:

[0005] On the one hand, the present application provides a chemical mechanical polishing method, which is applied to a polishing device, wherein the polishing device includes a grinding machine and a grinding head, wherein the grinding head is used to fix a semiconductor structure to be polished and can drive the semiconductor structure to be ground on the grinding machine, and the grinding machine is provided with a pressure sensor element for collecting pressure data, wherein the pressure data is used to indicate the pressure of the semiconductor structure acting on the grinding machine; the method includes:

[0006] Controlling the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition; the thickness of the residual layer meeting the preset thickness condition includes that the thickness of the residual layer reaches a first target thickness;

[0007] The polishing device is controlled to perform secondary grinding on the residual layer that meets the preset thickness condition, and endpoint detection data is detected during the secondary grinding process until the endpoint detection data indicates that the grinding endpoint is reached, thereby obtaining a target semiconductor structure; the endpoint detection data is obtained based on the pressure data conversion, and is used to indicate the pressure change of the semiconductor structure acting on the grinding machine table.

[0008] Furthermore, controlling the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition includes:

[0009] Controlling the polishing device to pre-grind the residual layer based on an initial grinding pressure until an initial grinding time is reached;

[0010] detecting a current thickness of the residual layer;

[0011] When the current thickness does not meet the preset thickness condition, the grinding time and grinding pressure of the grinding head are controlled based on the grinding amount corresponding to the initial grinding pressure and the initial grinding time, and the difference between the current thickness and the preset thickness condition, until it is detected that the current thickness of the residual layer meets the preset thickness condition.

[0012] Furthermore, the method further comprises:

[0013] The grinding time and grinding pressure used when the current thickness of the residual layer meets the preset thickness condition are associated with the information of the semiconductor structure and stored to obtain the historical grinding time and the historical grinding pressure to serve as the initial grinding time and initial grinding pressure for the next semiconductor structure grinding operation.

[0014] Further, the semiconductor structure is fixed to the mounting position of the grinding head, the mounting position includes at least one reference area and at least one voltage regulating area which are concentrically arranged, and the voltage regulating area is located at the periphery of the reference area;

[0015] The thickness of the residual layer satisfies the preset thickness condition, which includes: the thickness of the residual layer in the reference area reaches at least one of the first target thickness and the thickness of the residual layer in the pressure regulating area reaches the second target thickness;

[0016] The first target thickness is

[0017] The absolute value of the deviation between the second target thickness and the first target thickness is

[0018] Furthermore, the method for obtaining the initial grinding pressure includes:

[0019] If no historical grinding time and historical grinding pressure matching the information of the semiconductor structure are found, the preset grinding time is used as the initial grinding time, and the initial grinding pressure is determined based on at least one of the first target thickness and the second target thickness, the initial thickness of the residual layer and the polishing equipment parameters.

[0020] Further, the initial thickness includes the thickness of the first region of the residual layer located in the reference region, and the initial grinding pressure includes the pressure of the first region of the reference region; and the method for obtaining the pressure of the first region includes:

[0021] Determining a first thickness to be removed of the reference area according to a difference between the thickness of the first area and the first target thickness;

[0022] The grinding pressure corresponding to the first thickness to be removed is estimated according to the preset grinding time and the polishing equipment parameters to obtain the first area pressure.

[0023] Furthermore, the initial thickness also includes the thickness of the second region of the residual layer located in the pressure regulating area, and the initial grinding pressure also includes the pressure of the second region of the pressure regulating area; and the method for obtaining the pressure of the second region includes:

[0024] Determining a second thickness to be removed from the pressure regulating area according to a difference between the thickness of the second area and the second target thickness;

[0025] The grinding pressure corresponding to the second thickness to be removed is estimated according to the preset grinding time and the polishing equipment parameters to obtain the second area pressure.

[0026] Furthermore, the method further comprises:

[0027] If a historical polishing time and a historical polishing pressure matching the information of the semiconductor structure are found, the historical polishing time is used as the initial polishing time, and the historical polishing pressure is used as the initial polishing pressure.

[0028] On the other hand, the present application also provides a chemical mechanical polishing device, comprising:

[0029] a pre-grinding control module, used to control the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition; the thickness of the residual layer meeting the preset thickness condition includes that the thickness of the residual layer reaches a first target thickness;

[0030] A secondary grinding control module is used to control the polishing equipment to perform secondary grinding on the residual layer that meets the preset thickness condition, and detect endpoint detection data during the secondary grinding process until the endpoint detection data indicates that the grinding endpoint is reached, thereby obtaining a target semiconductor structure; the endpoint detection data is obtained based on the pressure data conversion, and is used to indicate the pressure change of the semiconductor structure acting on the grinding machine table.

[0031] On the other hand, the present application also provides a storage medium, in which at least one instruction or at least one program is stored, and the at least one instruction or the at least one program is loaded and executed by a processor to implement the chemical mechanical polishing method as described in any of the above items.

[0032] Implementing this application has the following beneficial effects:

[0033] 1. The present application pre-grinds the semiconductor structure to be polished until the thickness of the residual layer meets the preset thickness condition, which can reduce the thickness of the residual layer and reduce the unevenness, thereby providing a specified thickness for the subsequent secondary grinding stage, and then starts to detect the endpoint detection data from the secondary grinding. Compared with the traditional method of detecting the endpoint detection data of the entire process in a single grinding process, the time proportion of the pre-grinding stage in the endpoint detection curve formed by the endpoint detection data is removed, so that the endpoint detection curve generated by the endpoint detection data collected during the secondary grinding process can be effectively amplified and widened, and accordingly the capture window of the grinding endpoint in the endpoint detection data can be expanded, making the grinding endpoint more obvious and easy to capture, thereby improving the accuracy, reliability and stability of capturing the grinding endpoint, avoiding the residual layer residue or over-grinding of the semiconductor structure after the polishing is completed, greatly improving the accuracy of the polishing process and the product yield of the semiconductor structure, which is beneficial to the improvement of the performance of the semiconductor structure, and also saving the high manpower cost and time cost required for manual regulation, and avoiding waste of production capacity.

[0034] 2. The present application confirms the grinding time and grinding pressure according to the initial thickness of the semiconductor to be polished and the preset thickness conditions that need to be met after pre-grinding, which is also conducive to improving the accuracy and stability of grasping the grinding endpoint; at the same time, based on the reference area and the pressure adjustment area, the grinding pressure in different areas of the residual layer is zoned and regulated, which can effectively regulate the thickness and uniformity of each area in the semiconductor structure and improve the quality of the polished surface; and the real-time regulation of the grinding pressure and grinding time can overcome the problem that the grasping of the traditional grinding endpoint detection is affected by the life of the consumables of the polishing equipment, which greatly improves the accuracy and stability of grasping the grinding endpoint and improves the overall stability of the STI CMP process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments 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 creative work.

[0036] Figure 1 A logical structure diagram of a chemical mechanical polishing method provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of a polishing device provided in an embodiment of the present application;

[0038] Figure 3 A cross-sectional schematic diagram of a shallow trench isolation structure provided in an embodiment of the present application;

[0039] Figure 4 It is an endpoint detection curve diagram showing the endpoint detection data changing with time under an ideal state;

[0040] Figure 5 A schematic diagram of the partitioning of the reference area and the voltage regulating area in an exemplary embodiment of the present application;

[0041] Figure 6 A logical structure diagram of a pre-grinding method provided in an embodiment of the present application;

[0042] Figure 7 A logical structure diagram of a method for storing initial grinding time and initial grinding pressure provided in an embodiment of the present application;

[0043] Figure 8 A logical structure diagram of a method for determining an initial grinding pressure and an initial grinding time provided in an embodiment of the present application;

[0044] Fig. 9 A logical structure diagram of a method for determining the pressure of the first region provided in an embodiment of the present application;

[0045] Fig.10 A logical structure diagram of a method for determining the pressure of the second region provided in an embodiment of the present application;

[0046] Fig.11 A schematic diagram of a chemical mechanical polishing device provided in an embodiment of the present application;

[0047] Fig.12 A hardware structure block diagram of an electronic device for performing a chemical mechanical polishing method provided in an embodiment of the present application.

[0048] Wherein, the accompanying drawings are marked as follows:

[0049] 1-grinding machine table, 2-grinding head, 3-pressure sensing element, 4-substrate layer, 5-isolation layer, 6-oxide layer. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe specific objects or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that the depth direction of an element or layer is the direction perpendicular to the surface of the element or layer, and the direction of the cross section of an element or layer is the direction parallel to the surface of the element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When discussing a second element, component, region, layer or section, it does not necessarily mean that the first element, component, region, layer or section must be present.

[0053] In the existing STI CMP process, the grinding endpoint detection is affected by factors such as the consumables of the polishing equipment and the different thicknesses of the incoming materials of the semiconductor structure to be polished. The grabbing window of the later grinding endpoint is small, the grabbing difficulty is high, and residue or over-grinding is prone to occur. In order to solve this problem, the present application provides a chemical mechanical polishing method, device and storage medium, which are applied to the polishing equipment. First, the polishing equipment is controlled to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets the preset thickness condition, wherein the thickness of the residual layer meets the preset thickness condition including the situation that the thickness of the residual layer reaches the first target thickness; at this time, the thickness of the residual layer reaches a relatively thin specified thickness, that is, the first target thickness. a target thickness; then, controlling the polishing equipment to perform secondary grinding on the residual layer that meets the preset thickness condition, and detecting endpoint detection data during the secondary grinding process, until the endpoint detection data indicates that the secondary grinding has reached the grinding endpoint, thereby obtaining a target semiconductor structure, wherein the endpoint detection data is obtained by converting the pressure data collected by the pressure sensor element provided in the grinding machine table of the polishing equipment, and an endpoint detection curve corresponding to the secondary grinding process can be generated, which is used to indicate the pressure change of the semiconductor structure acting on the grinding machine table, and the grinding endpoint is used to indicate that the residual layer in the semiconductor structure has been removed and a state of another functional layer in the semiconductor structure different from the residual layer material has been reached.

[0054] The initial thickness of the residual layer is relatively thick, and the unevenness is relatively high. The chemical mechanical polishing method pre-grinds the semiconductor structure to be polished so that the thickness of the residual layer meets the preset thickness condition, thereby reducing the thickness of the residual layer and reducing the unevenness of the residual layer. That is, the thickness of the residual layer after pre-grinding is less than the thickness of the residual layer before pre-grinding, and the flatness of the residual layer after pre-grinding is greater than the flatness of the residual layer before pre-grinding. Then, the residual layer that meets the preset thickness condition is secondary ground, and the starting point of the secondary grinding is used as the starting condition for collecting endpoint detection data. Compared with the traditional process of collecting endpoint detection data during the entire process of single grinding, the time for collecting the uneven surface with larger thickness in the residual layer is shortened. The proportion of time spent in the process of grinding the surface to a relatively flat state in the entire endpoint detection process effectively increases the proportion of time spent in the subsequent secondary grinding process in the endpoint detection curve generated by the endpoint detection data, and correspondingly widens the capture window of the grinding endpoint, making the grinding endpoint more obvious and easier to capture, thereby reducing the difficulty of capturing the grinding endpoint and making it easier to capture the grinding endpoint detection data detected during the secondary grinding process, thereby improving the accuracy, reliability and stability of the grinding endpoint detection, accurately controlling the end of the polishing process, avoiding residues or over-grinding in the semiconductor structure, greatly improving the polishing yield and performance of the semiconductor structure, and avoiding waste of production capacity and labor costs.

[0055] The chemical mechanical polishing method of the present application is described in detail below. Figure 1 , the method comprising:

[0056] S101, controlling the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition.

[0057] Among them, the chemical mechanical polishing method is applied to polishing equipment, such as Figure 2 As shown, the polishing equipment includes a grinding machine 1 and a grinding head 2. The grinding head 2 is used to fix the semiconductor structure to be polished and can drive the semiconductor structure to be ground on the grinding machine 1. The grinding machine 1 is provided with a pressure sensor element 3 for collecting pressure data. The pressure data is used to indicate the pressure of the semiconductor structure acting on the grinding machine 1.

[0058] The chemical mechanical polishing method is used for shallow trench isolation technology, and the semiconductor structure is a shallow trench isolation structure, such as Figure 3As shown, the semiconductor structure to be polished includes a substrate layer 4, an isolation layer 5 and an oxide layer 6, the isolation layer 5 is located between the substrate layer 4 and the oxide layer 6, and grooves are provided between the substrate layer 4 and the isolation layer 5. In the previous semiconductor process, the oxide layer 6 covers the isolation layer 5 and fills the grooves. The oxide layer 6 is the residual layer to be removed, and the material of the isolation layer 5 is also different from that of the substrate layer. For example, in a shallow trench isolation structure, the material of the substrate layer 4 is mostly silicon material, the material of the isolation layer 5 is mostly silicon nitride material, and the material of the oxide layer 6 is mostly silicon oxide material; the chemical mechanical polishing method is used to remove the oxide layer 6 until the surface of the isolation layer 5 is exposed, and the polishing end point is accurately controlled to stop at the state where the oxide layer 6 is completely removed and just contacts the surface of the isolation layer 5, which can effectively remove the oxide layer 6 and avoid residue, and can also avoid over-wear and damage to the isolation layer 5 material or even the substrate layer 4 material under the isolation layer 5.

[0059] This step pre-grinds the residual layer of the semiconductor structure to a specified thickness. The thickness of the residual layer meets the preset thickness condition, the thickness of the residual layer is thinned, and the flatness of the residual layer is improved to a certain extent, so that in the subsequent S103 step of detecting the endpoint detection data, the time proportion of the stage of continuing to grind the thinned, uneven residual layer to a flat state in the entire endpoint detection data detection process is reduced, and accordingly, the time proportion of the subsequent grinding of the flat residual layer to a state of complete removal in the endpoint detection data detection process is increased, which is conducive to widening the grasping window of the grinding endpoint, making the grinding endpoint more obvious and easy to grasp, and improving the effectiveness, accuracy and stability of grasping the grinding endpoint, that is, realizing precise control of the polishing endpoint grasping, improving the polishing accuracy and reliability of the chemical mechanical polishing method, and improving the preparation yield and preparation accuracy and quality of the semiconductor structure after polishing.

[0060] S103, controlling the polishing equipment to perform secondary grinding on the residual layer that meets the preset thickness condition, and detecting endpoint detection data during the secondary grinding process, until the endpoint detection data indicates that the grinding endpoint is reached, to obtain a target semiconductor structure; the endpoint detection data is obtained based on the pressure data conversion, and is used to indicate the pressure change of the semiconductor structure acting on the grinding machine table.

[0061] The endpoint detection data is the grinding endpoint detection (EDP). In the present embodiment, the grinding endpoint detection is also called the motor torque endpoint detection. It is a detection method for judging the conversion process (grinding endpoint) of different film layers during the polishing process by utilizing the principle that the friction coefficients of different film layers in the semiconductor structure are different. During the polishing process, the forces and torques of different film layers acting on the grinding machine will also change accordingly. The motor torque change can be further converted into a current signal for output. Then the endpoint detection data is a series of current signals that change with time detected during the secondary grinding process. In this step, the pressure change of the semiconductor structure acting on the grinding machine during the polishing process can be detected to reflect or convert the changes in friction and motor torque, which are then converted into current signals for output, effectively indicating the different states of the residual layer of the semiconductor structure during the secondary grinding process.

[0062] For example, Figure 4 As shown in FIG. 1 , it is an endpoint detection curve of endpoint detection data plotted over time under an ideal state, wherein, during the change process from the first stage (step 1) to the second stage (step 2), the current signal gradually increases. This process occurs during the initial polishing of the oxide layer structure. In this process, the film layer materials ground are the same, all of which are oxide layer materials, and the oxide layer surface is uneven. The change of the current signal is mainly affected by the thickness of the oxide layer. Then, as the polishing proceeds, the surface of the oxide layer gradually becomes flat. When it reaches a flattened state, the current signal (and the motor torque signal, etc.) tends to be flat, reaching the second stage. In addition, a detection window can be inserted in the curve area to detect the flattening degree of the oxide layer. Afterwards, the second stage is transformed into the third stage (step 3). 3), it means that the isolation layer is ground, and the current signal decreases. This is because the isolation layer is ground, and the materials of the isolation layer and the oxide layer are different, resulting in different friction when the isolation layer is ground. At this time, the change in friction is mainly affected by the different friction coefficients of different film layers. As the friction decreases, the current signal also decreases accordingly. The turning point from the second stage to the third stage (the end point of the detection window) is the grinding end point, which is used to indicate that the oxide layer has been removed and the state of the isolation layer surface in the semiconductor structure has been reached. The material of the isolation layer is different from that of the residual layer; that is, in the chemical mechanical polishing method, the grinding end point is used to indicate that the residual layer has been removed and the state of a film layer of another material in the semiconductor structure has been reached.

[0063] However, the thick initial thickness will cause the time from the first stage to the second stage to be too long, and the time from the second stage to the third stage to be extremely short, resulting in that the smooth second stage is almost invisible in the endpoint detection curve. Instead, the first stage rises to the top and then directly drops, making it difficult to capture the inflection point from the second stage to the third stage, that is, it is difficult to grasp the grinding endpoint, which leads to problems such as over-grinding and damage to the semiconductor structure.

[0064] In step S103, the endpoint detection data is detected only when the secondary grinding starts. At this time, the residual layer has been thinned by pre-grinding, and the surface flatness can also be improved to a certain extent with the thinning in the pre-grinding stage. The change in the endpoint detection data (or the change in the endpoint detection curve) is related to the thickness of the residual layer. The grinding endpoint detection is started after the residual layer meets the preset thickness condition. The detected endpoint detection data can generate a more ideal endpoint detection curve, which can effectively reduce the time from the first stage to the second stage, widen the width of the detection window from the second stage to the third stage, make the grinding end point more obvious, and easier to capture, which greatly improves the accuracy and reliability of grinding end point capture.

[0065] Specifically, the semiconductor structure is fixed to the mounting position of the grinding head, and the mounting position includes multiple partitions, specifically including at least one reference area and at least one voltage regulation area concentrically arranged, and the voltage regulation area is located at the periphery of the reference area; it can be understood that the number of partitions of the mounting position can be 2, 3, 4, 5, 7, 8, etc.; the number of reference areas can be 1, 2, 3, 4, etc.; the number of voltage regulation areas can be 1, 2, 3, 4, etc.; to meet different partition and endpoint detection data capture requirements.

[0066] In some exemplary embodiments, the area of ​​the reference zone is greater than or equal to the area of ​​the pressure regulating zone. Correspondingly, the radial width of the reference zone is greater than the radial width of the pressure regulating zone. When the area of ​​the outer pressure regulating zone is relatively large, the area of ​​the inner reference zone is also relatively large, which is beneficial to improve the accuracy and stability of grasping the grinding end point at the corresponding position in the reference zone and the pressure regulating zone. In some preferred embodiments, based on the principle of equal area of ​​concentric circles, the area of ​​the reference zone is equal to the area of ​​the pressure regulating zone, and the capture of the end point detection data is more obvious. For example, Figure 5 As shown, the installation position is divided into 5 partitions, including three reference areas and two voltage regulation areas, and the area of ​​each reference area and each voltage regulation area is equal.

[0067] The thickness of the residual layer satisfies the preset thickness condition, including: the thickness of the residual layer in the reference area reaches the first target thickness and the thickness of the residual layer in the pressure regulating area reaches at least one of the second target thickness; in some exemplary embodiments, the thickness of the residual layer satisfies the preset thickness condition, including: the thickness of the residual layer in the reference area reaches the first target thickness; in other exemplary embodiments, the thickness of the residual layer satisfies the preset thickness condition, including: the thickness of the residual layer in the pressure regulating area reaches the second target thickness; in some preferred embodiments, the thickness of the residual layer in the reference area reaches the first target thickness, and the thickness of the residual layer in the pressure regulating area reaches the second target thickness, which can further optimize the measured endpoint detection data and its endpoint detection curve, and improve the grasping accuracy and stability of the grinding endpoint.

[0068] Specifically, in some exemplary embodiments, the first target thickness is determined based on the material of the semiconductor structure to be polished. The first target thickness refers to the average thickness of the residual layer in the central area of ​​the residual layer, that is, the residual layer located in the reference area, which can affect the time taken from the first stage to the second stage in the subsequent endpoint detection curve. For a shallow trench isolation structure, that is, when the residual layer is an oxide layer, the first target thickness is It can be understood that the first target thickness can be For example, the first target thickness can be etc.; within the first target thickness range, in the endpoint detection curve obtained by the secondary grinding process detection, the time consumed from the first stage to the second stage can be greatly shortened, so that the grasping window of the subsequent grinding endpoint is wider, and the turning point from the second stage to the third stage is more obvious, which can greatly improve the grasping accuracy and stability of the grinding endpoint.

[0069] Specifically, for a shallow trench isolation structure, that is, when the residual layer is an oxide layer, the absolute value of the deviation between the second target thickness and the first target thickness is That is, the deviation between the second target thickness and the first target thickness is as well as It can be understood that the absolute value of the deviation between the second target thickness and the first target thickness can be For example, the absolute value of the deviation between the second target thickness and the first target thickness can be etc.; the absolute value of the deviation is used to indicate the morphology of the residual layer in the voltage adjustment area, which has an impact on the second and third stages in the endpoint detection curve, and is also determined based on the material of the semiconductor structure to be polished. Within the absolute value range of the deviation, the turning point from the second stage to the third stage can also be made more obvious, greatly improving the accuracy and stability of grasping the grinding endpoint.

[0070] In addition, in some exemplary embodiments, the preset thickness condition is also determined based on the polishing liquid used in the grinding process, that is, the material of the semiconductor structure to be polished and the material of the polishing liquid can jointly affect the preset thickness condition, so that the grinding rate is different. For semiconductor structures other than the shallow trench isolation structure, the first target thickness and the absolute value of the deviation in the preset thickness condition can be a range different from the above, and the present invention does not make specific limitations on this.

[0071] Specifically, Figure 6 As shown, the polishing device is controlled to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition, that is, step S101 includes:

[0072] S202, controlling the polishing device to pre-grind the residual layer based on an initial grinding pressure until an initial grinding time is reached.

[0073] S204, detecting the current thickness of the residual layer.

[0074] S206, when the current thickness does not meet the preset thickness condition, the grinding time and grinding pressure of the grinding head are controlled based on the grinding amount corresponding to the initial grinding pressure and the initial grinding time, and the difference between the current thickness and the preset thickness condition, until it is detected that the current thickness of the residual layer meets the preset thickness condition.

[0075] In this step, the initial grinding pressure and the initial grinding time correspond to the estimated removal thickness of the residual layer. By detecting the actual value of the current thickness of the residual layer, the reliability of the initial grinding pressure and the initial grinding time can be verified. If the current thickness does not meet the preset thickness condition, it means that the initial grinding pressure and the initial grinding time are inaccurate. Based on the difference between the current thickness and the preset thickness condition, the grinding time and the grinding pressure of the grinding head can be adjusted in real time to remediate the residual layer until the current thickness of the residual layer meets the preset thickness condition. At the same time, the real-time regulation of the grinding time and the grinding pressure overcomes the limitation of the traditional STI CMP process that a large amount of experimental data is required to determine the grinding pressure and the grinding time, greatly reduces the labor cost, and overcomes the deficiency that the grasping of the grinding end point is affected by the life of the polishing equipment consumables, which is conducive to the accuracy of the subsequent grasping of the grinding end point and is also suitable for mass production.

[0076] Among them, the pressure of the grinding head is different in different areas corresponding to the installation position, resulting in different pressures in the reference area and the pressure adjustment area. In the process of regulation based on the difference between the current thickness and the preset thickness condition, the grinding amount removed in different areas through step S202 is first compared to regulate the grinding pressure so that the thickness of different areas after grinding is almost the same. Then, according to the current thickness of different areas, by comparing the difference between the current thickness of the residual layer in different areas and the preset thickness condition, if it has been ground too much, the grinding time is reduced, and if it is still ground too little, the grinding time is increased to achieve the regulation of the grinding time, so that the current thickness of the residual layer in different areas after grinding finally meets the preset thickness condition, and the regulation is convenient and quick.

[0077] Specifically, Figure 7 As shown, the method also includes:

[0078] S301, the grinding time and grinding pressure used when the current thickness of the residual layer meets the preset thickness condition are associated with the information of the semiconductor structure and stored to obtain the historical grinding time and the historical grinding pressure as the initial grinding time and the initial grinding pressure for the next semiconductor structure grinding operation.

[0079] Among them, if it is detected after step S204 that the current thickness of the residual layer meets the preset thickness condition, step S206 can be omitted, and the initial grinding time and the initial grinding pressure are directly associated with the information of the semiconductor structure and stored to obtain the historical grinding time and the historical grinding pressure; if it is detected after step S204 that the current thickness of the residual layer does not meet the preset thickness condition, step S206 is executed to adjust the grinding time and the grinding pressure, and the regulated grinding time and the grinding pressure used when the current thickness of the residual layer meets the preset thickness condition are associated with the information of the semiconductor structure and stored to obtain the historical grinding time and the historical grinding pressure; in this way, when the next semiconductor structure is subjected to a grinding operation, the historical grinding time and the historical grinding pressure stored in association with the semiconductor structure can be preferentially searched to simplify the control process of the chemical mechanical polishing method for the next semiconductor structure, save computing power, and also help improve polishing efficiency.

[0080] Specifically, Figure 8 As shown, the method also includes:

[0081] S402: If a historical polishing time and a historical polishing pressure matching the information of the semiconductor structure are found, the historical polishing time is used as the initial polishing time, and the historical polishing pressure is used as the initial polishing pressure.

[0082] Before step S202, first search for historical polishing time and historical polishing pressure that match the information of the semiconductor structure. If they can be found, the corresponding historical polishing time can be directly called as the initial polishing time, and the corresponding historical polishing pressure can be directly called as the initial polishing pressure to execute steps S202 to S206, which greatly simplifies the control process of the chemical mechanical polishing method for the semiconductor structure, saves computing power, and is also beneficial to improving polishing efficiency.

[0083] Specifically, Figure 8 As shown, the method for obtaining the initial grinding pressure includes:

[0084] S404: If no historical grinding time and historical grinding pressure matching the information of the semiconductor structure are found, the preset grinding time is used as the initial grinding time, and the initial grinding pressure is determined based on at least one of the first target thickness and the second target thickness, the initial thickness of the residual layer, and the polishing equipment parameters.

[0085] Among them, the information of the semiconductor includes the thickness information of the semiconductor structure, which is used to indicate the initial thickness of the residual layer of the semiconductor before polishing. The initial thickness of the residual layer is different, and the required grinding time and grinding pressure are also different. First, it is checked whether the initial thickness of the residual layer in the previous semiconductor structure is the same as the initial thickness of the residual layer in the semiconductor structure. If not found, the pre-set preset grinding time is used as the initial grinding time to determine the initial grinding pressure, thereby improving the accuracy of polishing, omitting human intervention and a large amount of experimental verification, and realizing an automatic closed-loop mode of passing goods, which is conducive to controlling the thickness accuracy and uniformity of each area on the semiconductor structure.

[0086] It should be noted that, taking the difference between the initial thickness and the target thickness (including at least one of the first target thickness and the second target thickness) as the thickness to be removed, the initial grinding pressure is positively correlated with the initial thickness to be removed, the initial grinding pressure is negatively correlated with the polishing equipment parameters, and the initial grinding pressure is negatively correlated with the initial grinding time.

[0087] In this embodiment, the polishing equipment parameters include a constant coefficient, a relative speed of the polishing surface and a correction coefficient; wherein the constant coefficient is related to the abrasive particles on the polishing contact surface, and due to the difference in the distribution of the polishing liquid, the constant coefficient is also different in different areas of the residual layer, that is, the constant coefficient depends on the characteristics of the polishing pad, the polishing liquid and the polishing material; the relative speed of the polishing surface is the head disk speed difference, and the relative speed is also different on the surface where the residual layer is located in different areas; the correction coefficient includes a pressure correction coefficient and a relative speed correction coefficient, and is also different in different areas corresponding to the polishing head installation position.

[0088] The relationship between the removal rate, initial grinding pressure and polishing equipment parameters can be expressed as the CMP mechanical action principle - Preston equation:

[0089] MRR (material removal rate)=k9P9α9V9β

[0090] Among them, k is a constant coefficient, P is the surface pressure (the surface pressure is different in different areas), V is the relative speed of the polishing surface, α is the correction coefficient of the surface pressure, and β is the correction coefficient of the relative speed.

[0091] It should be noted that the pressure of the grinding head is different in different areas, that is, the initial grinding pressure of the reference area and the pressure regulating area is different. First, the installation position is divided into reference area and pressure regulating area according to the pressure distribution; on the one hand, starting from the structure of the grinding head, such as Figure 5As shown, the control area of ​​the grinding head is divided into Z1, Z2, Z3, Z4 and Z5, among which Z5 is the center area with the strongest pressure control ability, the effective pressure is equal to the set pressure, and the grinding uniformity is good, so the Z5 pressure area is used as the reference area; while Z1 and Z2 are the edge areas, due to the boundary effect of the grinding head, the pressure control ability is the worst, and the effective pressure is not equal to the set pressure, so the Z1 and Z2 pressure areas are used as the pressure regulating areas; and the middle Z3 and Z4 are used as the middle area, and the effective pressure is the same as the pressure in the center area, so the Z3 and Z4 pressure areas are also used as reference areas; that is, according to the pressure of the grinding head, the installation position is divided into three reference areas and two pressure regulating areas, and the pressure regulating areas are located outside the reference areas; in addition, in other optional embodiments, different areas can also be divided into seven areas, eight areas, etc., to further improve the fineness of the regulation of the effective pressure in different areas, which is further conducive to improving the accuracy of grasping the grinding end point.

[0092] On the other hand, according to the principle of equal areas of concentric circles, the grinding head can be roughly divided into three areas: center, middle, and edge. The edge area is in the outer ring of the concentric circle. If the area occupied by the outer ring is much larger than that of the inner ring under the same radial width, the capture of the current signal is more obvious. Therefore, partitioning based on the principle of equal areas of concentric circles can also improve the effectiveness and reliability of the center area's capture of the current signal, and improve the accuracy and stability of capturing the grinding end point.

[0093] Specifically, Fig. 9 As shown, the initial thickness includes the thickness of the first region of the residual layer located in the reference region, and the initial grinding pressure includes the pressure of the first region of the reference region; and the method for obtaining the pressure of the first region includes:

[0094] S501 , determining a first thickness to be removed of the reference area according to a difference between the thickness of the first area and the first target thickness.

[0095] S503 , estimating the grinding pressure corresponding to the first thickness to be removed according to the preset grinding time and the polishing equipment parameters, to obtain the first region pressure.

[0096] Wherein, Zc_pre is defined as the measured thickness of the reference area (Zc is the center area) before pre-grinding, i.e., the first area thickness; Zc_post is defined as the measured thickness of the reference area after pre-grinding, i.e., the first target thickness; ΔZ c =Zc_pre-Zc_post is the grinding amount of the reference area, that is, the first thickness to be removed, P c is the effective pressure of the reference zone, i.e. the pressure of the first zone, V cis the relative speed of the reference area, T is the initial grinding time; according to the principle of mechanical action, we can get:

[0097] ΔZ c =k c 9P c 9α c *V c *β c 9T

[0098] In the reference region, k c It is a constant coefficient obtained through a large amount of time data, and the correction coefficient α of the first area pressure c and the correction factor β of the relative speed c Close to 1, that is, the pressure in the first region of the reference zone is equal to the set pressure.

[0099] The pressure in the first area is positively correlated with the first thickness to be removed, and negatively correlated with the relative speed and the initial grinding time. The pressure in the first area can be estimated according to the above formula as the initial grinding pressure of the reference area. The calculation logic is simple and convenient, and the effective pressure of the reference area can be quickly determined, thereby improving the accuracy and controllability of pre-grinding of the reference area, so that the reference area after pre-grinding can accurately meet the preset thickness conditions, thereby improving the accuracy and stability of grasping the grinding end point in the subsequent secondary grinding process.

[0100] Specifically, Fig.10 As shown, the initial thickness also includes the thickness of the second region of the residual layer located in the pressure regulating area, and the initial grinding pressure also includes the pressure of the second region of the pressure regulating area; the method for obtaining the pressure of the second region includes:

[0101] S602: Determine a second thickness to be removed from the pressure regulating area according to a difference between the thickness of the second region and the second target thickness.

[0102] S604: Estimate the grinding pressure corresponding to the second thickness to be removed according to the preset grinding time and the polishing equipment parameters to obtain the second region pressure.

[0103] Wherein, Ze_pre is defined as the measured thickness of the pressure regulating area (Ze is the edge area) before pre-grinding, i.e., the second area thickness; Ze_post is defined as the measured thickness of the pressure regulating area after pre-grinding, i.e., the second target thickness; ΔZ e =Ze_pre-Ze_post is the grinding amount in the pressure regulating zone, i.e. the second thickness to be removed, P e is the effective pressure of the pressure regulating area, i.e. the pressure of the second area, V e is the relative speed of the pressure regulating zone, T is the initial grinding time; according to the principle of mechanical action, we can get:

[0104] ΔZe =k e *P e *α e *V e *β e *T

[0105] The second target thickness can be obtained by the first target thickness and the absolute value of the deviation, and the first thickness to be removed and the second thickness to be removed satisfy the following relationship:

[0106] ΔZ c =ΔZ e +Q

[0107] Wherein, Q is the deviation between the first target thickness and the second target thickness.

[0108] In the pressure regulating area, due to the boundary effect of the grinding head, there is a difference between the pressure in the second area of ​​the pressure regulating area and the set pressure, but the correction coefficient α of the pressure in the first area is c and the correction factor β of the relative speed c If it is not easy to obtain, the equivalent first thickness to be removed can be obtained based on the second thickness to be removed and the deviation value according to the relationship between the first thickness to be removed and the second thickness to be removed, and then the equivalent first thickness to be removed is substituted into the mechanical action principle equation of the reference area to estimate the equivalent pressure. The equivalent pressure is the pressure in the second area, that is, the effective pressure in the edge area. In this way, the effective pressure of the pressure regulating area can be quickly determined, and the accuracy and controllability of pre-grinding of the pressure regulating area can be improved, so that the pressure regulating area after pre-grinding can accurately meet the preset thickness conditions, thereby improving the accuracy and stability of grasping the grinding end point in the subsequent secondary grinding process.

[0109] Corresponding to the chemical mechanical polishing method provided by the above embodiment of the present invention, the chemical mechanical polishing device provided by the embodiment of the present invention can implement the chemical mechanical polishing method in the above method embodiment, wherein, Fig.11 As shown, the chemical mechanical polishing device may include:

[0110] A pre-grinding control module 1110 is used to control the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition; the thickness of the residual layer meets the preset thickness condition including that the thickness of the residual layer reaches a first target thickness;

[0111] The secondary grinding control module 1120 is used to control the polishing equipment to perform secondary grinding on the residual layer that meets the preset thickness condition, and detect endpoint detection data during the secondary grinding process, until the endpoint detection data indicates that the grinding endpoint is reached, to obtain a target semiconductor structure; the endpoint detection data is obtained based on the pressure data conversion, and is used to indicate the pressure change of the semiconductor structure acting on the grinding machine.

[0112] Specifically, the pre-grinding control module 1210 may include:

[0113] A pre-grinding submodule, used for controlling the polishing device to pre-grind the residual layer based on the initial grinding pressure until the initial grinding time is reached;

[0114] A thickness detection module, used to detect the current thickness of the residual layer;

[0115] The control module is used to control the grinding time and grinding pressure of the grinding head based on the endpoint detection data corresponding to the pre-grinding process when the current thickness does not meet the preset thickness condition, until it is detected that the current thickness of the residual layer meets the preset thickness condition.

[0116] Specifically, the chemical mechanical polishing device may also include:

[0117] A storage module is used to store the grinding time and grinding pressure used when the current thickness of the residual layer meets the preset thickness condition in association with the information of the semiconductor structure, so as to obtain the historical grinding time and the historical grinding pressure as the initial grinding time and initial grinding pressure for the next semiconductor structure grinding operation.

[0118] Specifically, the chemical mechanical polishing device may also include:

[0119] An initial grinding pressure determination module is used to determine the initial grinding pressure based on a preset grinding time as the initial grinding time if no historical grinding time and historical grinding pressure matching the information of the semiconductor structure are found, and based on at least one of a first target thickness and a second target thickness, and the initial thickness of the residual layer and polishing equipment parameters.

[0120] Specifically, the initial grinding pressure determination module may include:

[0121] A first thickness to be removed determining module, used for determining a first thickness to be removed of the reference area according to a difference between the thickness of the first area and the first target thickness;

[0122] The first region pressure determination module is used to estimate the grinding pressure corresponding to the first thickness to be removed according to the preset grinding time and the polishing equipment parameters to obtain the first region pressure.

[0123] Specifically, the initial grinding pressure determination module may include:

[0124] A second thickness to be removed determining module, used for determining a second thickness to be removed of the pressure regulating area according to a difference between the thickness of the second area and the second target thickness;

[0125] The second region pressure determination module is used to estimate the grinding pressure corresponding to the second thickness to be removed according to the preset grinding time and the polishing equipment parameters to obtain the second region pressure.

[0126] Specifically, the chemical mechanical polishing device may also include:

[0127] The initial polishing condition determination module is used to use the historical polishing time as the initial polishing time and the historical polishing pressure as the initial polishing pressure if the historical polishing time and the historical polishing pressure matching the information of the semiconductor structure are found.

[0128] It should be noted that the chemical mechanical polishing device provided in the above embodiment, when realizing its functions, is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the chemical mechanical polishing device provided in the above embodiment belongs to the same concept as the method embodiment, and its specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0129] The chemical mechanical polishing device includes a processor and a memory, wherein the processor (or CPU (Central Processing Unit)) is the core component, and its function is mainly to interpret memory instructions and process data fed back by each module; the structure of the processor is roughly divided into an operation logic component and a register component, etc. The operation logic component mainly performs related logical calculations (such as shift operations, logical operations, fixed-point or floating-point arithmetic operations and address operations, etc.), and the register component is used to temporarily store instructions, data and addresses.

[0130] The memory is a memory device that can be used to store software programs and modules. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory. The memory mainly includes a program storage area and a data storage area, wherein the program storage area can store an operating system, which may include but is not limited to: Windows system (an operating system), Linux (an operating system), etc., and this application does not limit this; in addition, it can also store applications required for functions, for example, at least one instruction suitable for being loaded and executed by the processor is also stored in the storage space of the memory, and these instructions can be one or more computer programs (including program codes); and the data storage area can store data created according to the use of the device, etc.; accordingly, the memory can also include a memory controller to provide the processor with access to the memory.

[0131] The method embodiments provided in the embodiments of the present application can be executed in devices such as mobile terminals, computer terminals, servers or similar computing devices. Fig.12 1 is a hardware structure block diagram of an electronic device for a chemical mechanical polishing method provided in an embodiment of the present application. Fig.12 As shown, the device 1200 may have relatively large differences due to different configurations or performances, and may include one or more central processing units (CPU) 1210 (the processor 1210 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 1230 for storing data, and one or more storage media 1220 (such as one or more mass storage devices) for storing application programs 1223 or data 1222. Among them, the memory 1230 and the storage medium 1220 can be short-term storage or permanent storage. The program stored in the storage medium 1220 may include one or more modules, each of which may include a series of instruction operations in the electronic device. Furthermore, the central processor 1212 can be configured to communicate with the storage medium 1220 to execute a series of instruction operations in the storage medium 1220 on the device 1200. The device 1200 may also include one or more power supplies 1260, one or more wired or wireless network interfaces 1250, one or more input and output interfaces 1240, and / or one or more operating systems 1221, such as Windows ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

[0132] The input / output interface 1240 may be used to receive or send data via a network. The specific example of the network may include a wireless network provided by a communication provider of the device 1200. In one example, the input / output interface 1240 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the input / output interface 1240 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0133] It can be understood by those skilled in the art that Fig.12 The structure shown is for illustration only and does not limit the structure of the above-mentioned device. Fig.12 More or fewer components as shown, or with Fig.12 Different configurations shown.

[0134] An embodiment of the present application also provides a storage medium, in which at least one instruction or at least one program is stored, and the at least one instruction or the at least one program is loaded and executed by a processor to implement the chemical mechanical polishing control method described above; optionally, the medium can be located in at least one network server among multiple network servers of a computer network; in addition, the medium can include but is not limited to random access memory (RAM), read-only memory (ROM), non-volatile memory (NVM), U disk, mobile hard disk, disk storage device, flash memory device, other volatile solid-state storage devices and other storage media that can store program codes.

[0135] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A chemical mechanical polishing method, applied to a polishing device, wherein the polishing device comprises a grinding machine and a grinding head, wherein the grinding head is used to fix a semiconductor structure to be polished and can drive the semiconductor structure to be ground on the grinding machine, and a pressure sensor element is provided in the grinding machine for collecting pressure data, wherein the pressure data is used to indicate the pressure of the semiconductor structure acting on the grinding machine; characterized in that: The method comprises: Controlling the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition; the thickness of the residual layer meeting the preset thickness condition includes that the thickness of the residual layer reaches a first target thickness; The polishing device is controlled to perform secondary grinding on the residual layer that meets the preset thickness condition, and endpoint detection data is detected during the secondary grinding process until the endpoint detection data indicates that the grinding endpoint is reached, thereby obtaining a target semiconductor structure; the endpoint detection data is obtained based on the pressure data conversion, and is used to indicate the pressure change of the semiconductor structure acting on the grinding machine table.

2. The chemical mechanical polishing method according to claim 1, characterized in that: The controlling the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition comprises: Controlling the polishing device to pre-grind the residual layer based on an initial grinding pressure until an initial grinding time is reached; detecting a current thickness of the residual layer; When the current thickness does not meet the preset thickness condition, the grinding time and grinding pressure of the grinding head are controlled based on the grinding amount corresponding to the initial grinding pressure and the initial grinding time, and the difference between the current thickness and the preset thickness condition, until it is detected that the current thickness of the residual layer meets the preset thickness condition.

3. The chemical mechanical polishing method according to claim 2, characterized in that: The method further comprises: The grinding time and grinding pressure used when the current thickness of the residual layer meets the preset thickness condition are associated with the information of the semiconductor structure and stored to obtain the historical grinding time and the historical grinding pressure to serve as the initial grinding time and initial grinding pressure for the next semiconductor structure grinding operation.

4. The chemical mechanical polishing method according to claim 1, characterized in that: The semiconductor structure is fixed to the mounting position of the grinding head, the mounting position includes at least one reference area and at least one voltage regulating area which are arranged concentrically, and the voltage regulating area is located at the periphery of the reference area; The thickness of the residual layer satisfies the preset thickness condition, which includes: the thickness of the residual layer in the reference area reaches at least one of the first target thickness and the thickness of the residual layer in the pressure regulating area reaches the second target thickness; The first target thickness is The absolute value of the deviation between the second target thickness and the first target thickness is 5. The chemical mechanical polishing method according to any one of claims 2 to 4, characterized in that: The method for obtaining the initial grinding pressure comprises: If no historical grinding time and historical grinding pressure matching the information of the semiconductor structure are found, the preset grinding time is used as the initial grinding time, and the initial grinding pressure is determined based on at least one of the first target thickness and the second target thickness, the initial thickness of the residual layer and the polishing equipment parameters.

6. The chemical mechanical polishing method according to claim 5, characterized in that: The initial thickness includes the thickness of the first region of the residual layer located in the reference region, and the initial grinding pressure includes the pressure of the first region of the reference region; and the method for obtaining the pressure of the first region includes: Determining a first thickness to be removed of the reference area according to a difference between the thickness of the first area and the first target thickness; The grinding pressure corresponding to the first thickness to be removed is estimated according to the preset grinding time and the polishing equipment parameters to obtain the first area pressure.

7. The chemical mechanical polishing method according to claim 5, characterized in that: The initial thickness also includes the thickness of the second region of the residual layer located in the pressure regulating area, and the initial grinding pressure also includes the pressure of the second region of the pressure regulating area; the method for obtaining the pressure of the second region includes: Determining a second thickness to be removed from the pressure regulating area according to a difference between the thickness of the second area and the second target thickness; The grinding pressure corresponding to the second thickness to be removed is estimated according to the preset grinding time and the polishing equipment parameters to obtain the second area pressure.

8. The chemical mechanical polishing method according to claim 5, characterized in that: The method further comprises: If a historical polishing time and a historical polishing pressure matching the information of the semiconductor structure are found, the historical polishing time is used as the initial polishing time, and the historical polishing pressure is used as the initial polishing pressure.

9. A chemical mechanical polishing device, characterized in that: include: A pre-grinding control module, used to control the polishing device to pre-grind the residual layer of the semiconductor structure until the thickness of the residual layer meets a preset thickness condition; The thickness of the residual layer satisfies a preset thickness condition, including the thickness of the residual layer reaching a first target thickness; A secondary grinding control module is used to control the polishing equipment to perform secondary grinding on the residual layer that meets the preset thickness condition, and detect endpoint detection data during the secondary grinding process until the endpoint detection data indicates that the grinding endpoint is reached, thereby obtaining a target semiconductor structure; the endpoint detection data is obtained based on the pressure data conversion, and is used to indicate the pressure change of the semiconductor structure acting on the grinding machine table.

10. A storage medium, characterized in that: The storage medium stores at least one instruction or at least one program, and the at least one instruction or the at least one program is loaded and executed by the processor to implement the chemical mechanical polishing method according to any one of claims 1 to 8.

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