Chemical mechanical polishing method, device, equipment and storage medium

Abstract

The present application provides a chemical mechanical polishing method, device, equipment and storage medium, the method comprising: obtaining the current polishing system parameters of the wafer polishing system; determining the polishing time of the wafer to be polished through a polishing time determination model; determining the polishing thickness difference of the wafer after polishing; if the polishing thickness difference of the wafer after polishing is greater than a preset thickness difference threshold, updating the polishing time determination model according to the polishing data of the wafer after polishing, and determining the first polishing time of the next wafer to be polished; and determining the second polishing time of the next wafer to be polished according to the polishing thickness difference and polishing time of the wafer after polishing; and determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time. The present application can determine the polishing time of each wafer to be polished separately, thereby improving the accuracy of determining the polishing time of the wafer to be polished.

Description

Technical Field

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

[0002] During the wafer manufacturing process, it is necessary to obtain the thickness of the wafer before polishing, and use the thickness before polishing to determine the polishing time, so that the wafer is polished according to the polishing time so that the thickness of the wafer meets the expectations.

[0003] However, in the actual production process, the thickness of a wafer before polishing is usually measured in dozens of batches of wafer products, and the polishing time of all wafers is determined using the pre-polishing thickness and a given polishing rate. However, the pre-polishing thickness of different wafers is not exactly the same, and determining the polishing time of all wafers as one value will lead to the problem of low accuracy in determining the wafer polishing time. Summary of the invention

[0004] In view of this, the present application provides a chemical mechanical polishing method, device, equipment and storage medium to at least partially solve the above problems.

[0005] According to a first aspect of the present application, a chemical mechanical polishing method is provided, the method comprising: obtaining current polishing system parameters of a wafer polishing system, the polishing system parameters comprising pressure of each area of ​​a polishing head, thickness of a polishing pad, and usage time of a polishing head; using a polishing time determination model, predicting the polishing time of a wafer to be polished according to the polishing system parameters, and determining the polishing time of the wafer to be polished, wherein the polishing time determination model is trained based on polishing system parameters and polishing data corresponding to historically polished wafers, the polishing data comprising a difference between polishing time and polishing thickness, and the polishing data does not include wafer thickness before polishing; and predicting the polishing time of the wafer to be polished according to the polishing time. After polishing, the polishing thickness difference of the polished wafer is determined according to the actual thickness of the polished wafer after polishing and the target thickness after polishing; if the polishing thickness difference of the polished wafer is greater than the preset thickness difference threshold, the polishing time determination model is updated according to the polishing data of the polished wafer, and the first polishing time of the next wafer to be polished is determined according to the updated polishing time determination model; and the second polishing time of the next wafer to be polished is determined according to the polishing data of the polished wafer; the polishing time of the next wafer to be polished is determined according to the difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished.

[0006] According to a second aspect of the present application, a chemical mechanical polishing device is provided, the device comprising: an acquisition module, used to acquire current polishing system parameters of a wafer polishing system, the polishing system parameters comprising pressure of each area of ​​a polishing head, thickness of a polishing pad, and usage time of a polishing head; a prediction module, used to predict the polishing time of a wafer to be polished according to the polishing system parameters through a polishing time determination model, and determine the polishing time of the wafer to be polished, wherein the polishing time determination model is trained based on the polishing system parameters and polishing data corresponding to historically polished wafers, the polishing data comprising polishing time and polishing thickness difference, and the polishing data does not include wafer thickness before polishing; a first determination module, used to determine the polishing thickness difference of the polished wafer according to the actual thickness after polishing and the target thickness after polishing of the polished wafer after polishing after polishing the wafer to be polished according to the polishing time; an update module, used to update the polishing time determination model according to the polishing data of the polished wafer if the polishing thickness difference of the polished wafer is greater than a preset thickness difference threshold, and determine the first polishing time of the next wafer to be polished according to the updated polishing time determination model; The second determination module is used to determine the second polishing time of the next wafer to be polished according to the polishing data of the polished wafer; the third determination module is used to determine the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished.

[0007] According to the third aspect of the present application, there is provided an electronic device, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; the memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the chemical mechanical polishing method described in the first aspect.

[0008] According to a fourth aspect of the present application, a computer storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the chemical mechanical polishing method as described in the first aspect is implemented.

[0009] According to the fifth aspect of the present application, a wafer polishing system is provided, comprising: a polishing device for polishing a wafer to be polished; a controller, the controller being communicatively connected to the polishing device; control instructions stored in the controller, which, when executed, causes the controller to execute the chemical mechanical polishing method as described in the first aspect, so as to control the wafer polishing system to polish the wafer to be polished.

[0010] According to the chemical mechanical polishing method provided by the present application, when a wafer is polished, a polishing time determination model is used to predict the polishing time of the wafer to be polished, thereby improving the accuracy of determining the polishing time of the wafer to be polished, and effectively avoiding the problem of low accuracy of wafer polishing time in the prior art. At the same time, after the wafer to be polished is polished using the polishing time, the polishing time determination model is updated according to the polishing data of the polished wafer, and the first polishing time of the next wafer to be polished is determined according to the updated polishing time determination model, and then the first polishing time of the next wafer to be polished can be determined by the updated polishing time determination model, which can improve the accuracy of determining the first polishing time by the polishing time determination model, and further, by determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time and performing polishing, the accuracy of determining the polishing time of the next wafer to be polished can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0012] Figure 1 is a structural schematic diagram of a wafer polishing system according to the present application;

[0013] Figure 2 A flow chart of steps of a chemical mechanical polishing method according to an embodiment of the present application;

[0014] Figure 3 A flowchart of a method for determining a second polishing time according to an embodiment of the present application;

[0015] Figure 4 A flowchart of a method for determining a polishing rate according to an embodiment of the present application;

[0016] Figure 5 A flowchart of the steps of updating a polishing time determination model according to an embodiment of the present application;

[0017] Figure 6 A flowchart of the steps of determining the polishing time of the next wafer to be polished according to an embodiment of the present application;

[0018] Figure 7 is a flow chart of a chemical mechanical polishing method according to another embodiment of the present application;

[0019] Figure 8is a structural block diagram of a chemical mechanical polishing device according to the present application;

[0020] Fig. 9 It is a schematic diagram of the structure of an electronic device according to the present application. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of this application.

[0022] The specific implementation of this application is further explained below in conjunction with the drawings of this application.

[0023] In the actual production process, the thickness of a wafer before polishing is usually measured in dozens of batches of wafer products, and the polishing time of all wafers is determined using the pre-polishing thickness and a given polishing rate. Specifically, for example, for tungsten process buff, it is difficult for the measuring machine in the prior art to accurately measure the tungsten thickness greater than 24nm in mass production. Therefore, a wafer is selected from dozens of batches of tungsten process products for pre-polishing measurement, and the measured thickness is used as the pre-polishing thickness of other wafers. Alternatively, in the CU process, when CU metal interconnect wiring is performed, CU is usually deposited after etching the silicon oxide layer, and finally the CU is polished by CMP. However, there will be certain pits in the CU channel at this time, so the silicon oxide will be polished off a layer to flatten the silicon oxide and CU surfaces. Since silicon oxide is deposited and polished by the previous process, it is difficult to obtain its wafer pre-polishing thickness in the CUCMP process, and only the actual thickness of the wafer after polishing can be obtained.

[0024] Figure 1 A wafer polishing system 100 is shown, which includes a chemical mechanical polishing device and a controller (not shown in the figure), and the controller is communicatively connected to the polishing device; control instructions are stored in the controller, and when the control instructions are executed, the controller executes the chemical mechanical polishing method of the present application to control the wafer polishing system to polish the wafer to be polished.

[0025] Furthermore, if Figure 1As shown, the chemical mechanical polishing equipment mainly includes a carrier 102 for holding a wafer and a polishing plate 104 covered with a polishing pad 106. During wafer polishing, the carrier 102 can press the wafer onto the polishing pad 106, and drive the wafer to rotate relative to the polishing pad 106 (refer to the indicating arrow F1) and move horizontally (refer to the indicating arrow F2), and the polishing pad 106 also rotates at the same time (refer to the indicating arrow F3). Through the relative movement between the carrier 102 and the polishing plate 104, the polishing pad 106 rubs against the surface of the wafer to polish the wafer.

[0026] Furthermore, the present application provides a chemical mechanical polishing method, which is applied to Figure 1 The wafer polishing system shown in the figure is specifically implemented by the controller to perform the chemical mechanical polishing method. The specific steps of the chemical mechanical polishing method are as follows Figure 2 As shown, the method includes the following steps S201-S206.

[0027] S201, obtaining current polishing system parameters of the wafer polishing system.

[0028] In the present application, before polishing the wafer to be polished, the current polishing system parameters of the wafer polishing system are obtained, wherein the polishing system parameters in the present application may include the pressure of each area of ​​the polishing head, the thickness of the polishing pad, the use time of the polishing head, etc. Specifically, when obtaining the current polishing system parameters of the wafer polishing system, the present application may read the data obtained by each sensor in the wafer polishing system to determine the current polishing system parameters of the wafer polishing system. For example, a counter may be set to determine the thickness of the polishing pad and the use time of the polishing head through the counting data of the counter. The pressure of each area of ​​the polishing head may be determined by setting a pressure sensor, and the current polishing system parameters of the wafer polishing system may also be set.

[0029] In an example, there are three wafers to be polished, namely wafer #1 to be polished, wafer #2 to be polished and wafer #3 to be polished. Before polishing wafer #1 to be polished, the current polishing system parameters of the wafer polishing system are obtained. Before polishing wafer #2 to be polished, the current polishing system parameters of the wafer polishing system are obtained. Similarly, before polishing each wafer to be polished, the current polishing system parameters of the wafer polishing system are obtained.

[0030] S202 , predicting the polishing time of the wafer to be polished according to the polishing system parameters by using a polishing time determination model, and determining the polishing time of the wafer to be polished.

[0031] In the present application, after obtaining the corresponding polishing system parameters of the wafer to be polished, the polishing system parameters are input into the polishing time determination model, so as to predict the polishing time of the wafer to be polished through the polishing time determination model and determine the polishing time of the wafer to be polished.

[0032] In one example, the polishing time determination model of the present application is trained based on the polishing system parameters and polishing data corresponding to the historical polished wafers. The polishing time determination model can specifically be a BP neural network or a LSTM neural network.

[0033] Before the polishing time determination model is used, the polishing system parameters and polishing data corresponding to historical wafers are collected, and the polishing system parameters and polishing data corresponding to the historical wafers are used as input, and the polishing time of the wafer is used as output to train the polishing time determination model. Specifically, the polishing system parameters and polishing data corresponding to the historical wafers are divided into a training set and a test set, the training set is used to train the polishing time determination model, and the test set is used to verify the polishing time determination model. When the verification passes, the trained polishing time determination model is applied to S202 in this application.

[0034] In this application, the polishing data includes the polishing time and the polishing thickness difference, and the polishing data does not include the wafer thickness before polishing. This application is mainly aimed at processes where it is difficult to obtain the wafer thickness before polishing, so the polishing data used for training does not include the wafer thickness before polishing.

[0035] S203, after polishing the wafer to be polished according to the polishing time, determine the polishing thickness difference of the polished wafer according to the actual thickness of the polished wafer after polishing and the target thickness after polishing.

[0036] In the present application, after determining the polishing time of the wafer to be polished, the wafer to be polished is polished using the determined polishing time. After polishing is completed, the actual thickness of the polished wafer after polishing is obtained, and the difference between the actual thickness of the polished wafer after polishing and the target thickness after polishing is used to determine the polishing thickness difference of the polished wafer.

[0037] In the present application, the target thickness after polishing refers to the thickness that the wafer is expected to reach after polishing, the actual thickness after polishing refers to the thickness of the wafer after the wafer is actually polished, and the wafer thickness before polishing refers to the thickness of the wafer before polishing.

[0038] In one example, if the wafer to be polished is #1, after polishing the wafer to be polished #1 using a determined polishing time, the actual thickness of the polished wafer #1 after polishing is obtained, and the polishing thickness difference of the polished wafer #1 after polishing is determined using the actual thickness of the polished wafer #1 after polishing and the target thickness after polishing.

[0039] S204, if the polishing thickness difference of the polished wafer is greater than a preset thickness difference threshold, updating the polishing time determination model according to the polishing data of the polished wafer, and determining the first polishing time of the next wafer to be polished according to the updated polishing time determination model.

[0040] If the polishing thickness difference of the wafer after polishing is less than or equal to the preset thickness difference threshold, the polishing time determination model is not updated.

[0041] In the present application, after determining the polishing thickness difference of the polished wafer, the polishing thickness difference of the polished wafer is compared with a preset thickness difference threshold. If the polishing thickness difference of the polished wafer is greater than the preset thickness difference threshold, the inaccuracy of the polishing time is determined, and the polishing data of the polished wafer is used to update the polishing time determination model. When determining the polishing time of the next wafer to be polished, the updated polishing time determination model is used to determine the first polishing time of the next wafer to be polished.

[0042] In one example, the preset thickness difference threshold of the present application may be between 1 and 2 microns. Specifically, the preset thickness difference threshold may be determined according to actual polishing accuracy requirements.

[0043] In one example, if the polishing thickness difference of wafer #1 after polishing is greater than a preset thickness difference threshold, the polishing data of wafer #1 after polishing is used to update the polishing time determination model, and the updated polishing time determination model is used to determine the first polishing time of wafer #2 to be polished, wherein the polishing data of wafer #1 after polishing may include the polishing time of wafer #1 after polishing and the polishing thickness difference of wafer #1 after polishing.

[0044] In one example, if the polishing thickness difference of the polished wafer is less than or equal to a preset thickness difference threshold, the polishing time determination model is used to determine the polishing time of the next wafer to be polished.

[0045] S205, determining a second polishing time for a next wafer to be polished according to the polishing data of the polished wafer.

[0046] In the present application, if the polishing thickness difference of the polished wafer is greater than the preset thickness difference threshold, while updating the polishing time determination model, the second polishing time of the next wafer to be polished is determined based on the polishing thickness difference and polishing time of the polished wafer.

[0047] In one example, if the polishing thickness difference of the polished wafer #1 is greater than a preset thickness difference threshold, the polishing thickness difference of the polished wafer #1 and the polishing time are used to determine the second polishing time of the wafer #2 to be polished. Specifically, the time required to remove the thickness corresponding to the polishing thickness difference can be calculated based on the polishing rate and the polishing thickness difference, and then the time required to remove the thickness corresponding to the polishing thickness difference can be added to the polishing time of the polished wafer #1 to obtain the second polishing time of the next wafer to be polished.

[0048] It should be noted that Figure 2 In the process shown in , S204 is executed first and then S205. In other implementations, S205 may be executed first and then S204, or S204 and S205 may be executed in parallel, all of which are within the protection scope of the present application.

[0049] S206 , determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished.

[0050] In the present application, after determining the first polishing time and the second polishing time of the next wafer to be polished, the polishing time of the next wafer to be polished is determined as the first polishing time or the second polishing time according to the difference between the first polishing time and the second polishing time.

[0051] "Determined as" in this application can be understood as making the former equal to the latter. For example, the polishing time of the next wafer to be polished is determined to be the first polishing time or the second polishing time, that is, the polishing time of the next wafer to be polished is equal to the first polishing time or the second polishing time.

[0052] In one example, after determining the first polishing time and the second polishing time of the wafer #2 to be polished, the polishing time of the wafer #2 to be polished is determined as the first polishing time or the second polishing time according to the difference between the first polishing time and the second polishing time.

[0053] The chemical mechanical polishing method of the present application first obtains the current polishing system parameters of the polishing system, and through the polishing time determination model, can separately determine the polishing time of each wafer to be polished, thereby improving the accuracy of determining the polishing time of the wafer to be polished, and effectively avoiding the problem of low accuracy in determining the polishing time of the wafer in the prior art due to determining the polishing time of all wafers as one value, thereby improving the polishing effect.

[0054] Further, by the method of the present application, when polishing a tungsten process wafer, the polishing time determination model can be used to predict the polishing time of the wafer to be polished, thereby improving the accuracy of determining the polishing time of the wafer to be polished, effectively avoiding the problem of low accuracy of the wafer polishing time caused by selecting a wafer from dozens of batches of tungsten process products for pre-polishing measurement in the prior art, and using the measured thickness as the pre-polishing thickness of other wafers. At the same time, after the wafer to be polished is polished using the polishing time, if the polishing thickness difference of the polished wafer is greater than the preset thickness difference threshold, the polishing time determination model is updated according to the polishing data of the polished wafer, and the first polishing time of the next wafer to be polished is determined according to the updated polishing time determination model, and then the first polishing time of the next wafer to be polished can be determined by the updated polishing time determination model, which can improve the accuracy of determining the first polishing time by the polishing time determination model, and further, by determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time, the accuracy of determining the polishing time of the next wafer to be polished can be further improved.

[0055] Furthermore, the polishing time determination model in the present application predicts the polishing time of the wafer to be polished according to the polishing system parameters, and determines the polishing time of the wafer to be polished, which may include the following steps:

[0056] S2021, if the polishing time determination model is changed to an updated polishing time determination model, the polishing system parameters are input into the updated polishing time determination model to determine the polishing time of the wafer to be polished.

[0057] In the present application, when the polishing time determination model is changed to an updated polishing time determination model, the polishing system parameters corresponding to the wafer to be polished are input into the updated polishing time determination model to determine the polishing time of the wafer to be polished using the updated polishing time determination model.

[0058] In one example, when determining the polishing time of wafer #2 to be polished, the polishing time determination model is changed to an updated polishing time determination model, and the wafers to be polished include wafer #3 to be polished, wafer #4 to be polished...wafer #N to be polished. Then, the polishing system parameters corresponding to wafer #3 to be polished, wafer #4 to be polished...wafer #N to be polished are input into the updated polishing time determination model to determine the polishing time of the wafer to be polished using the updated polishing time determination model.

[0059] The present application determines the polishing time of the wafer to be polished by inputting the polishing system parameters into the updated polishing time determination model. The updated polishing time determination model can be used to determine the polishing time of the wafer to be polished, thereby improving the accuracy of determining the polishing time.

[0060] Further, the present application may include the following steps to determine the second polishing time of the next wafer to be polished according to the polishing data of the polished wafer: Figure 3 As shown:

[0061] S2051, determining a first adjustment time according to the absolute value of the polishing thickness difference of the polished wafer and the polishing rate.

[0062] In the present application, when determining the second polishing time of the next wafer to be polished, the polishing thickness difference of the polished wafer is first determined, and the first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer and the polishing rate, and then the second polishing time is determined using the first adjustment time. Specifically, the first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer and the ratio of the polishing rate.

[0063] In one example, a first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer #1 and the polishing rate, and a second polishing time of the wafer #2 to be polished is determined by using the first adjustment time.

[0064] S2052: If the first adjustment time is less than or equal to a preset adjustment time threshold, determine a second polishing time according to the sum of the polishing time of the polished wafer and the first adjustment time.

[0065] In the present application, after determining the first adjustment time, the first adjustment time is compared with the preset adjustment time threshold. If the first adjustment time is less than or equal to the preset adjustment time threshold, the second polishing time is determined based on the sum of the polishing time of the polished wafer and the first adjustment time.

[0066] In one example, if the first adjustment time is less than or equal to the preset adjustment time threshold, the second polishing time of the to-be-polished wafer #2 is determined according to the sum of the polishing time of the polished wafer #1 and the first adjustment time.

[0067] In an example, the preset adjustment time threshold may be 0.5-0.75 s, which may be specifically determined according to the material of the wafer, wherein the higher the hardness of the wafer material, the larger the preset adjustment time threshold is generally.

[0068] S2053: If the first adjustment time is greater than a preset adjustment time threshold, determine a second polishing time according to the positive or negative value of the polishing thickness difference of the wafer after polishing.

[0069] In the present application, after determining the first adjustment time, the first adjustment time is compared with the preset adjustment time threshold. If the first adjustment time is greater than the preset adjustment time threshold, the second polishing time is determined based on the positive or negative difference in the polishing thickness of the wafer.

[0070] Specifically, if the polishing thickness difference of the polished wafer is positive, the second polishing time is determined according to the sum of the polishing time of the polished wafer and the first adjustment time; if the polishing thickness difference of the polished wafer is negative, the second polishing time is determined according to the difference between the polishing time of the polished wafer and the first adjustment time.

[0071] The present application determines the first adjustment time based on the absolute value of the polishing thickness difference of the polished wafer and the polishing rate. The first adjustment time can be used to accurately calculate the second polishing time of the next wafer to be polished. The second polishing time can then be used to accurately calculate the polishing time of the next wafer to be polished, thereby further improving the accuracy of the polishing time calculation of the wafer to be polished.

[0072] Furthermore, in the chemical mechanical polishing method of the present application, the method for determining the first polishing rate according to the polishing pad thickness and / or the use time of the polishing head comprises the following steps, specifically: Figure 4 As shown:

[0073] S20510, determining whether the polishing pad thickness is within a preset polishing pad thickness range, and whether the polishing head usage time is within a preset usage time range.

[0074] S20511, if the polishing pad thickness is within a preset polishing pad thickness range, and the use time of the polishing head is within a preset use time range, determine the polishing rate to be a preset polishing rate.

[0075] In the present application, before calculating the first adjustment time, the polishing pad thickness and the polishing head usage time are first obtained, and the polishing pad thickness is compared with a preset polishing pad thickness range. At the same time, the polishing head usage time is compared with a preset usage time range. If the polishing pad thickness is within the preset polishing pad thickness range and the polishing head usage time is within the preset usage time range, the polishing rate is determined to be the preset polishing rate.

[0076] S20512: If at least one of the polishing pad thickness and the polishing head usage time is not within the corresponding preset range, the polishing rate is determined as the first polishing rate.

[0077] In the present application, if the polishing pad thickness does not fall within the preset polishing pad thickness range, and the polishing head usage time falls within the preset usage time range, the first polishing rate is determined according to the polishing pad thickness; if the polishing pad thickness falls within the preset polishing pad thickness range, and the polishing head usage time does not fall within the preset usage time range, the first polishing rate is determined according to the polishing head time; if the polishing pad thickness does not fall within the preset polishing pad thickness range, and the polishing head usage time does not fall within the preset usage time range, the first polishing rate is determined according to the polishing pad thickness and the polishing head usage time. The first polishing rate of the present application is different from the preset polishing rate, and specifically, the first polishing rate is greater than or less than the preset polishing rate.

[0078] Specifically, when the polishing pad thickness does not belong to the preset polishing pad thickness range, and the use time of the polishing head belongs to the preset use time range, when determining the first polishing rate according to the polishing pad thickness, first compare the polishing pad thickness with the endpoint value of the preset polishing pad thickness range, determine the endpoint value adjacent to the polishing pad thickness in the preset polishing pad thickness range, further determine the first adjustment coefficient according to the polishing pad thickness and the endpoint value adjacent to the polishing pad thickness, and then determine the first polishing rate according to the preset polishing rate and the first adjustment coefficient. Specifically, in the present application, when calculating the first adjustment coefficient, the difference between the polishing pad thickness and the endpoint value adjacent to the polishing pad thickness can be first calculated, and the smaller value between the polishing pad thickness and the endpoint value adjacent to the polishing pad thickness can be determined at the same time, and the first adjustment coefficient can be determined by using the absolute value of the difference between the polishing pad thickness and the endpoint value adjacent to the polishing pad thickness to the smaller value between the polishing pad thickness and the endpoint value adjacent to the polishing pad thickness.

[0079] In one example, the preset polishing pad thickness range includes a first endpoint value and a second endpoint value, and the second endpoint value is greater than the first endpoint value. If the endpoint value adjacent to the polishing pad thickness is the second endpoint value, the absolute value of the difference is first calculated based on the polishing pad thickness and the second endpoint value, and it is determined that the second endpoint value is less than the polishing pad thickness. The first adjustment coefficient is further determined using the ratio of the absolute value of the difference to the second endpoint value.

[0080] Specifically, when the polishing pad thickness belongs to the preset polishing pad thickness range, and the polishing head usage time does not belong to the preset usage time range, when determining the first polishing rate according to the polishing head time, first compare the polishing head usage time with the preset usage time range to determine the endpoint value adjacent to the preset usage time range and the polishing head usage time, and further determine the second adjustment coefficient according to the polishing head usage time and the endpoint value adjacent to the polishing head usage time, and then determine the first polishing rate according to the preset polishing rate and the second adjustment coefficient. Specifically, when calculating the second adjustment coefficient, the present application can first calculate the difference between the polishing head usage time and the endpoint value adjacent to the polishing head usage time, and at the same time determine the smaller value between the polishing head usage time and the endpoint value adjacent to the polishing head usage time, and use the absolute value of the difference between the polishing head usage time and the endpoint value adjacent to the polishing head usage time, and the ratio of the smaller value between the polishing head usage time and the endpoint value adjacent to the polishing head usage time, to determine the second adjustment coefficient.

[0081] In one example, the preset usage time range includes a first endpoint value and a second endpoint value, the second endpoint value is greater than the first endpoint value, if the endpoint value adjacent to the polishing head usage time is the first endpoint value, firstly, the absolute value of the difference is calculated based on the polishing head usage time and the first endpoint value, and at the same time, the polishing head usage time is less than the first endpoint value, and further the ratio of the absolute value of the difference to the first endpoint value is used to determine the second adjustment coefficient.

[0082] Specifically, when the polishing pad thickness does not fall within the preset polishing pad thickness range, and the polishing head usage time does not fall within the preset usage time range, then when determining the first polishing rate based on the polishing pad thickness and the polishing head usage time, first determine the first adjustment coefficient based on the polishing pad thickness and the endpoint value adjacent to the polishing pad thickness, and at the same time determine the second adjustment coefficient based on the polishing head usage time and the endpoint value adjacent to the polishing head usage time, further determine the third adjustment coefficient based on the sum of the first adjustment coefficient and the second adjustment coefficient, and then determine the first polishing rate using the third adjustment coefficient and the preset polishing rate.

[0083] The present application obtains the polishing pad thickness and the usage time of the polishing head, and uses the polishing pad thickness and the usage time of the polishing head to adjust the preset polishing rate, and further accurately determines the first adjustment time according to the first polishing rate, and then can accurately determine the second polishing time of the next wafer to be polished according to the usage of the polishing consumables, so that the second polishing time of the next wafer to be polished can be used to accurately determine the polishing time of the next wafer to be polished, further improving the accuracy of determining the polishing time of the wafer to be polished.

[0084] Further, in the present application, updating the polishing time determination model according to the polishing data of the polished wafer may include the following steps, specifically: Figure 5 As shown:

[0085] S2041, determining polishing data of multiple other wafers according to the position of the polishing data of the polished wafer in the database.

[0086] In the present application, after polishing the wafer to be polished, the polishing data of the polished wafer is stored in a database, and the position of the polishing data of the polished wafer in the database is obtained, and further, the polishing data of multiple other wafers adjacent to the polishing data of the polished wafer is obtained.

[0087] In one example, if polished wafer #3 is polished, the polishing data of polished wafer #3 is stored in the database, and the position of the polishing data of polished wafer #3 in the database is obtained, and the polishing data of multiple other wafers adjacent to the polishing data of polished wafer #3 is obtained.

[0088] In one example, the number of multiple other wafers in the present application can be 2. If the polishing thickness difference of the polished wafer #3 is greater than the preset thickness difference threshold, the polishing data of 2 other wafers adjacent to the polishing data of the polished wafer #3 are obtained.

[0089] S2042: Update the polishing time determination model according to the polishing data of the polished wafer and the polishing data of multiple other wafers.

[0090] In the present application, after the polishing data of a plurality of other wafers are determined, the polishing time determination model is updated using the polishing data of the polished wafer and the polishing data of a plurality of other wafers.

[0091] In one example, if the polishing data of multiple other wafers include polishing data of two other wafers adjacent to the polishing data of the polished wafer #3, the polishing time determination model is updated using the polishing data of the polished wafer #3 and the polishing data of the two other wafers adjacent to the polishing data of the polished wafer #3.

[0092] In the present application, by obtaining the position of the polishing data of the polished wafer in the database and obtaining the polishing data of multiple other wafers adjacent to the polishing data of the polished wafer, the most recent polishing data can be used to update the polishing time determination model, which can improve the accuracy of the polishing time output by the updated polishing time determination model and avoid the problem of inaccurate polishing time output by the updated polishing time determination model due to the use of polishing data that is too old to update the polishing time determination model.

[0093] Further, in the present application, determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time may include the following steps: Figure 6 As shown:

[0094] S2060, determining the difference between the first polishing time and the second polishing time.

[0095] S2061: If the difference between the first polishing time and the second polishing time is greater than or equal to a preset value, the polishing time of the next wafer to be polished is determined as the second polishing time.

[0096] In the present application, when determining the polishing time of a next wafer to be polished, the polishing time difference between the first polishing time and the second polishing time of the next wafer to be polished is first calculated, and the polishing time difference is compared with a preset value. If the polishing time difference is greater than or equal to the preset value, it is determined that the first polishing time determined by the updated polishing time model is inaccurate, and then the second polishing time is determined as the polishing time of the next wafer to be polished.

[0097] In one example, the preset value in the present application may be 0.15 seconds, or other values, which may be determined based on the material of the wafer.

[0098] S2062: If the difference between the first polishing time and the second polishing time is less than a preset value, the polishing time of the next wafer to be polished is determined as the first polishing time.

[0099] In the present application, when determining the polishing time of a wafer to be polished, the polishing time difference between the first polishing time and the second polishing time of the wafer to be polished is first calculated, and the polishing time difference is compared with a preset value. If the polishing time difference is less than the preset value, it is determined that the first polishing time determined by the updated polishing time model is accurate, and then the first polishing time is determined as the polishing time of the next wafer to be polished.

[0100] In an example, if the next wafer to be polished is #2, and the first polishing time and the second polishing time corresponding to the wafer to be polished are #2, and the difference between the first polishing time and the second polishing time is greater than or equal to a preset value, the polishing time of the wafer to be polished #2 is determined to be the second polishing time, and if the difference between the first polishing time and the second polishing time is less than the preset value, the polishing time of the wafer to be polished #2 is determined to be the first polishing time.

[0101] The present application can accurately determine whether the first polishing time output by the updated polishing time determination model is accurate by calculating the polishing time difference between the first polishing time and the second polishing time of the next wafer to be polished. If it is determined that the first polishing time determined by the updated polishing time model is inaccurate, the second polishing time is determined as the polishing time of the next wafer to be polished. If it is determined that the first polishing time determined by the updated polishing time model is accurate, the first polishing time is determined as the polishing time of the next wafer to be polished. The polishing time of the next wafer to be polished can be accurately determined, thereby further improving the accuracy of determining the polishing time of the wafer to be polished.

[0102] For further information, see Figure 7 As shown, this application combines Figure 7 The chemical mechanical polishing method is further described as follows: Figure 7As shown, in step ①, before performing chemical mechanical polishing, first collect the polishing system parameters and polishing data corresponding to the historically polished wafers, after collecting the polishing system parameters and polishing data corresponding to the historically polished wafers, transmit the polishing system parameters and polishing data corresponding to the historically polished wafers to the database through the transmission protocol, and at the same time, establish an initial polishing time determination model, step ② use the polishing system parameters and polishing data corresponding to the historically polished wafers to train the initial polishing time determination model, determine the model weight file in the initial polishing time determination model, and then determine the polishing time determination model. Further, after completing the training of the model, step ③ obtains the polishing system parameters matching the first wafer to be polished (#1) in the database, and inputs the polishing system parameters into the polishing time determination model to determine the polishing time of the first wafer to be polished (#1) using the polishing time determination model, step ④ after determining the polishing time of the first wafer to be polished (#1), polishes the first wafer to be polished (#1) using the wafer polishing system, step ⑤ after polishing the first wafer to be polished (#1), updates the polishing data of the first polished wafer (#1) to the database, and updates the polishing time determination model using the latest polishing data to determine the updated polishing time determination model, step ⑥ repeats steps ①②③④⑤ to predict the polishing time of the second wafer to be polished (#2) using the updated polishing time determination model.

[0103] Furthermore, the present application provides a chemical mechanical polishing device, such as Figure 8 As shown, the device comprises:

[0104] An acquisition module 801 is used to acquire current polishing system parameters of the wafer polishing system, where the polishing system parameters include pressure of each area of ​​the polishing head, polishing pad thickness, and polishing head usage time;

[0105] Prediction module 802, used to predict the polishing time of the wafer to be polished according to the polishing system parameters through a polishing time determination model, and determine the polishing time of the wafer to be polished, wherein the polishing time determination model is trained based on the polishing system parameters and polishing data corresponding to the historical polished wafers, the polishing data includes the polishing time and the polishing thickness difference, and the polishing data does not include the wafer thickness before polishing;

[0106] A first determination module 803 is used to determine a polishing thickness difference of the polished wafer according to the actual thickness of the polished wafer and the target thickness of the polished wafer after polishing the wafer to be polished according to the polishing time;

[0107] An updating module 804 is configured to update the polishing time determination model according to the polishing data of the polished wafer if the polishing thickness difference of the polished wafer is greater than a preset thickness difference threshold, and determine the first polishing time of the next wafer to be polished according to the updated polishing time determination model; and

[0108] A second determination module 805 is used to determine a second polishing time of a next wafer to be polished according to the polishing data of the polished wafer;

[0109] The third determining module 806 is used to determine the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished.

[0110] The chemical mechanical polishing device of this embodiment is used to implement the corresponding chemical mechanical polishing methods in the aforementioned multiple method embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here. In addition, the functional implementation of each module in the chemical mechanical polishing device of this embodiment can refer to the description of the corresponding parts in the aforementioned method embodiments, which will not be repeated here.

[0111] Reference Fig. 9 , shows a schematic diagram of the structure of an electronic device according to the present application. The specific embodiments of the present application do not limit the specific implementation of the electronic device.

[0112] like Fig. 9 As shown, the electronic device may include: a processor (processor) 902 , a communication interface (Communications Interface) 904 , a memory (memory) 906 , and a communication bus 908 .

[0113] in:

[0114] The processor 902 , the communication interface 904 , and the memory 906 communicate with each other via a communication bus 908 .

[0115] The communication interface 904 is used to communicate with other electronic devices or servers.

[0116] The processor 902 is used to execute the program 910, and specifically can execute the relevant steps in the above-mentioned chemical mechanical polishing method embodiment.

[0117] Specifically, the program 910 may include program codes, which include computer operation instructions.

[0118] The processor 902 may be a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the present application. The one or more processors included in the smart device may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0119] The memory 906 is used to store the program 910. The memory 906 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0120] Program 910 can be specifically used to enable processor 902 to perform the following operations: obtain current polishing system parameters of the wafer polishing system, wherein the polishing system parameters include pressure of each area of ​​the polishing head, thickness of the polishing pad, and usage time of the polishing head; predict the polishing time of the wafer to be polished according to the polishing system parameters through a polishing time determination model, and determine the polishing time of the wafer to be polished, wherein the polishing time determination model is trained based on the polishing system parameters and polishing data corresponding to historically polished wafers, wherein the polishing data includes the difference between the polishing time and the polishing thickness, and the polishing data does not include the wafer thickness before polishing; and polish the wafer to be polished according to the polishing time. Afterwards, the polishing thickness difference of the polished wafer is determined according to the actual thickness of the polished wafer after polishing and the target thickness after polishing; if the polishing thickness difference of the polished wafer is greater than the preset thickness difference threshold, the polishing time determination model is updated according to the polishing data of the polished wafer, and the first polishing time of the next wafer to be polished is determined according to the updated polishing time determination model; and the second polishing time of the next wafer to be polished is determined according to the polishing data of the polished wafer; the polishing time of the next wafer to be polished is determined according to the difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished.

[0121] The specific implementation of each step in program 910 can refer to the corresponding description of the corresponding steps and units in the above-mentioned chemical mechanical polishing method embodiment, which will not be repeated here. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described equipment and modules can refer to the corresponding process description in the above-mentioned method embodiment, which will not be repeated here.

[0122] The present application also provides a computer program product, including computer instructions, which instruct a computing device to execute operations corresponding to any chemical mechanical polishing method in the above-mentioned multiple method embodiments.

[0123] It should be pointed out that, according to the needs of implementation, the various components / steps described in this application can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of this application.

[0124] The above-described method according to the present application may be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or as computer code that is originally stored in a remote recording medium or a non-transitory machine-readable medium downloaded via a network and will be stored in a local recording medium, so that the method described herein can be stored in such software processing on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It is understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by a computer, a processor, or hardware, the chemical mechanical polishing method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the chemical mechanical polishing method shown herein, the execution of the code converts the general-purpose computer into a dedicated computer for executing the chemical mechanical polishing method shown herein.

[0125] Those of ordinary skill in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0126] The above implementation modes are only used to illustrate the present application, and are not intended to limit the present application. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions also belong to the scope of the present application, and the scope of patent protection of the present application shall be limited by the claims.

Claims

1. A chemical mechanical polishing method, characterized in that: The method comprises: Obtaining current polishing system parameters of the wafer polishing system, wherein the polishing system parameters include pressure of each area of ​​the polishing head, thickness of the polishing pad, and usage time of the polishing head; The polishing time of the wafer to be polished is predicted according to the polishing system parameters by a polishing time determination model, and the polishing time of the wafer to be polished is determined, wherein the polishing time determination model is trained according to the polishing system parameters and polishing data corresponding to the historically polished wafers, the polishing data includes the polishing time and the polishing thickness difference, and the polishing data does not include the wafer thickness before polishing; After polishing the wafer to be polished according to the polishing time, determining a polishing thickness difference of the polished wafer according to an actual thickness of the polished wafer after polishing and a target thickness after polishing; If the polishing thickness difference of the polished wafer is greater than a preset thickness difference threshold, updating the polishing time determination model according to the polishing data of the polished wafer, and determining the first polishing time of the next wafer to be polished according to the updated polishing time determination model; and Determining a second polishing time for the next wafer to be polished according to the polishing data of the polished wafer; Determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished; Determining the second polishing time of the next wafer to be polished according to the polishing data of the polished wafer includes: determining a first adjustment time according to the absolute value of the polishing thickness difference of the polished wafer and the polishing rate, and determining the second polishing time using the first adjustment time; Wherein, the polishing rate includes a preset polishing rate and a first polishing rate, and the first polishing rate is different from the preset polishing rate; If the polishing pad thickness is within a preset polishing pad thickness range, and the use time of the polishing head is within a preset use time range, the polishing rate is determined to be the preset polishing rate, and the first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer and the preset polishing rate; If at least one of the polishing pad thickness and the polishing head usage time does not fall within the corresponding preset range, the polishing rate is determined as a first polishing rate, and the first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer and the first polishing rate; The method for determining a first polishing rate according to a polishing pad thickness and / or a polishing head usage time comprises the following steps: If the polishing pad thickness does not fall within the preset polishing pad thickness range, determining a first adjustment coefficient according to the polishing pad thickness and an endpoint value adjacent to the polishing pad thickness in the preset polishing pad thickness range, and determining the first polishing rate according to the preset polishing rate and the first adjustment coefficient; If the polishing head usage time does not belong to the preset polishing head usage time range, determining a second adjustment coefficient according to the polishing head usage time and an endpoint value adjacent to the polishing head usage time in the preset polishing head usage time range, and determining the first polishing rate according to the preset polishing rate and the second adjustment coefficient; If the polishing pad thickness does not fall within the preset polishing pad thickness range, and the polishing head usage time does not fall within the preset polishing head usage time range, the first polishing rate is determined according to the preset polishing rate and a third adjustment coefficient, wherein the third adjustment coefficient is determined according to the sum of the first adjustment coefficient and the second adjustment coefficient.

2. The method according to claim 1, characterized in that Determining the second polishing time of the next wafer to be polished according to the polishing data of the polished wafer also includes: If the first adjustment time is less than or equal to a preset adjustment time threshold, determining the second polishing time according to the sum of the polishing time of the polished wafer and the first adjustment time; If the first adjustment time is greater than the preset adjustment time threshold, the second polishing time is determined according to the positive or negative value of the polishing thickness difference of the polished wafer.

3. The method according to claim 2, characterized in that If the first adjustment time is greater than the preset adjustment time threshold, determining the second polishing time according to the positive or negative value of the polishing thickness difference of the polished wafer includes: If the polishing thickness difference of the polished wafer is positive, determining the second polishing time according to the sum of the polishing time of the polished wafer and the first adjustment time; If the polishing thickness difference of the polished wafer is negative, the second polishing time is determined according to the difference between the polishing time of the polished wafer and the first adjustment time.

4. The method according to claim 1, characterized in that: The updating of the polishing time determination model according to the polishing data of the polished wafer comprises: Determining polishing data of a plurality of other wafers according to the position of the polishing data of the polished wafer in the database, wherein the polishing data of the polished wafer is stored in the database after polishing the wafer to be polished; The polishing time determination model is updated according to the polishing data of the polished wafer and the polishing data of the other wafers.

5. The method according to claim 1, characterized in that Determining the polishing time of the next wafer to be polished according to the difference between the first polishing time and the second polishing time includes: If the difference between the first polishing time and the second polishing time is greater than or equal to a preset value, the polishing time of the next wafer to be polished is determined as the second polishing time; If the difference between the first polishing time and the second polishing time is smaller than the preset value, the polishing time of the next wafer to be polished is determined as the first polishing time.

6. A chemical mechanical polishing device, characterized in that: The device comprises: An acquisition module is used to acquire current polishing system parameters of the wafer polishing system, wherein the polishing system parameters include pressure of each area of ​​the polishing head, thickness of the polishing pad, and use time of the polishing head; A prediction module is used to predict the polishing time of the wafer to be polished according to the polishing system parameters through a polishing time determination model, and determine the polishing time of the wafer to be polished, wherein the polishing time determination model is trained based on the polishing system parameters and polishing data corresponding to the historically polished wafers, the polishing data includes the polishing time and the polishing thickness difference, and the polishing data does not include the wafer thickness before polishing; A first determination module is used to determine a polishing thickness difference of the polished wafer according to an actual thickness of the polished wafer and a target thickness of the polished wafer after polishing the wafer to be polished according to the polishing time; An updating module, configured to update the polishing time determination model according to the polishing data of the polished wafer if the polishing thickness difference of the polished wafer is greater than a preset thickness difference threshold, and determine the first polishing time of the next wafer to be polished according to the updated polishing time determination model; A second determining module, used for determining a second polishing time of the next wafer to be polished according to the polishing data of the polished wafer; A third determining module, configured to determine a polishing time for the next wafer to be polished according to a difference between the first polishing time and the second polishing time, so as to perform chemical mechanical polishing on the next wafer to be polished; The second determination module is specifically used to: determine the first adjustment time according to the absolute value of the polishing thickness difference of the polished wafer and the polishing rate, and determine the second polishing time using the first adjustment time; Wherein, the polishing rate includes a preset polishing rate and a first polishing rate, and the first polishing rate is different from the preset polishing rate; If the polishing pad thickness is within a preset polishing pad thickness range, and the use time of the polishing head is within a preset use time range, the polishing rate is determined to be the preset polishing rate, and the first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer and the preset polishing rate; If at least one of the polishing pad thickness and the polishing head usage time does not fall within the corresponding preset range, the polishing rate is determined as a first polishing rate, and the first adjustment time is determined according to the absolute value of the polishing thickness difference of the polished wafer and the first polishing rate; The method for determining a first polishing rate according to a polishing pad thickness and / or a polishing head usage time comprises the following steps: If the polishing pad thickness does not fall within the preset polishing pad thickness range, determining a first adjustment coefficient according to the polishing pad thickness and an endpoint value adjacent to the polishing pad thickness in the preset polishing pad thickness range, and determining the first polishing rate according to the preset polishing rate and the first adjustment coefficient; If the polishing head usage time does not belong to the preset polishing head usage time range, determining a second adjustment coefficient according to the polishing head usage time and an endpoint value adjacent to the polishing head usage time in the preset polishing head usage time range, and determining the first polishing rate according to the preset polishing rate and the second adjustment coefficient; If the polishing pad thickness does not fall within the preset polishing pad thickness range, and the polishing head usage time does not fall within the preset polishing head usage time range, the first polishing rate is determined according to the preset polishing rate and a third adjustment coefficient, wherein the third adjustment coefficient is determined according to the sum of the first adjustment coefficient and the second adjustment coefficient.

7. An electronic device, characterized in that: include: A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the chemical mechanical polishing method according to any one of claims 1 to 5.

8. A computer storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the chemical mechanical polishing method as described in any one of claims 1 to 5 is implemented.

9. A computer program product, characterized in that The method comprises computer instructions, wherein the computer instructions instruct a computing device to execute operations corresponding to the chemical mechanical polishing method as claimed in any one of claims 1 to 5.

10. A wafer polishing system, characterized in that: include: Polishing equipment, used for polishing the wafer to be polished; A controller, wherein the controller is in communication with the polishing device; the controller stores control instructions, and when the control instructions are executed, the controller executes the chemical mechanical polishing method as described in any one of claims 1 to 5 to control the wafer polishing system to polish the wafer to be polished.

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