Wafer chemical mechanical planarization method

Abstract

The present application provides a wafer chemical mechanical planarization method, comprising the following steps: providing a plurality of wafers to be polished; sequentially performing wafer polishing steps on the wafers according to set process parameters; obtaining current data of the wafers during the wafer polishing process; providing historical data of the wafer polishing steps; correcting the set process parameters according to the current data of the current wafer combined with the historical data to obtain a corrected polishing thickness and a corrected polishing time; performing the polishing step on the next wafer according to the corrected polishing thickness and the corrected polishing time; performing the step of obtaining the current data of the wafers multiple times during the wafer polishing process, and obtaining the corrected polishing thickness and the corrected polishing time each time the current data is obtained, and performing the polishing step on the next wafer according to the new corrected polishing thickness and the new corrected polishing time. The wafer chemical mechanical planarization method of the present application has small variance between the polishing and grinding results of the wafers in the same batch.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wafer manufacturing technology, in particular to a wafer chemical mechanical planarization method. BACKGROUND

[0002] In the process of wafer manufacturing, polishing is needed to make the wafer reach the design target parameters. Chemical mechanical planarization is a commonly used polishing process. Referring to Figure 1 In the process of wafer polishing, the polishing disc 1 rotates along the axis, and the polishing head 2 can apply pressure to multiple areas to polish the wafer. The polishing liquid nozzle 3 sprays chemical liquid on the polishing disc 1, and the polishing liquid spreads over the entire polishing disc with the rotation of the polishing disc 1. The dresser 4 runs on the polishing disc according to the set trajectory to continuously polish the polishing disc 1. In the prior art, the same set of process parameters are usually used for polishing the wafers in the same batch. However, due to the actual shape differences between the wafers in the same batch, the polishing results of the wafers after polishing with the same set of process parameters have large variance. Therefore, a solution is needed to solve the problem of large variance between the polishing results in the chemical mechanical planarization process. SUMMARY

[0003] Therefore, the present application provides a wafer chemical mechanical planarization method to solve the problem of large variance between the polishing results in the chemical mechanical planarization process.

[0004] The present application provides a wafer chemical mechanical planarization method, comprising the following steps: providing a plurality of wafers to be polished; sequentially performing a wafer polishing step on the wafers according to a set of process parameters; the set of process parameters includes a set polishing thickness and a set polishing time; obtaining current data of the wafers during the wafer polishing process; the current data includes the pre-polishing thickness of the wafers and the post-polishing thickness of the wafers; providing historical data of the wafer polishing step; the historical data includes the historical pre-polishing thickness, the historical post-polishing thickness, and the historical polishing time of all wafers before the current wafer; correcting the set of process parameters according to the current data of the current wafer combined with the historical data to obtain a corrected polishing thickness and a corrected polishing time; performing a polishing step on the next wafer according to the corrected polishing thickness and the corrected polishing time; performing the step of obtaining current data of the wafer multiple times during the wafer polishing process, and obtaining a corrected polishing thickness and a corrected polishing time each time the current data is obtained, and performing a polishing step on the next wafer according to the new corrected polishing thickness and the new corrected polishing time.

[0005] Optionally, the obtaining the current data of the wafer comprises: collecting a plurality of points on the wafer before polishing to obtain a pre-polishing thickness of each point; and the pre-polishing thickness of the wafer is calculated according to the following formula:

[0006] Pre = Average (P1, P2, P3, …, Pn) (1)

[0007] In the formula, Pre is the pre-polishing thickness of the wafer; P1, P2, P3, …, Pn are the pre-polishing thicknesses of the points respectively; and Average (P1, P2, P3, …, Pn) is the average of the pre-polishing thicknesses of the points.

[0008] Optionally, the pre-polishing thickness of the wafer is calculated according to the following formula:

[0009] Pre = Average (Pre_n1, Pre_n2, …) (2)

[0010] In the formula, Pre is the pre-polishing thickness of the wafer; Pre_n1, Pre_n2, … are the pre-polishing thicknesses of the first wafer, the second wafer, …, and the last wafer before the wafer in the batch; and Average (Pre_n1, Pre_n2, …) is the average of the pre-polishing thicknesses of the first wafer, the second wafer, …, and the last wafer before the wafer in the batch.

[0011] Optionally, the obtaining the current data of the wafer comprises: collecting a plurality of points on the wafer after polishing to obtain a post-polishing thickness of each point; and the post-polishing thickness of the wafer is calculated according to the following formula:

[0012] Post = Average (Post1, Post2, Post3, …, Postn) (3)

[0013] In the formula, Post is the post-polishing thickness of the wafer;

[0014] Post1, Post2, Post3, …, Postn are the post-polishing thicknesses of the points respectively;

[0015] Average (Post1, Post2, Post3, …, Postn) is the average of the post-polishing thicknesses of the points.

[0016] Optionally, the corrected polishing thickness is calculated according to the following formula:

[0017] R(c) = (Pre-Pi+Ri)*(c) …………………… (4)

[0018] In the formula, R is the revised polishing thickness; c is the order value of the current wafer in the batch of wafers; Pre is the pre-polishing thickness of the current wafer, which is calculated by formula (1) or formula (2); Pi is the ideal pre-polishing thickness of the wafer, which is obtained according to the setting; Ri is the setting polishing thickness, which is obtained according to the setting; f is the sum of the revised weights.

[0019] Optionally, the sum of the revised weights is obtained by the following formula:

[0020] F(c+1) = (c)*(c) + (c-1)*(c-1) + (c-2)*(c-2) …………………… (5)

[0021] In the formula, F is the sum of the revised weights; w is the order weight, w(c) is the order weight of the current wafer, w(c-1) is the order weight of the first previous wafer, and (c-2) is the order weight of the second previous wafer; w decreases as the number of the order of the wafer increases; Y is the result weight, which is obtained according to the absolute value of the difference between the post-polishing thickness of the wafer and the setting post-polishing thickness, and Y increases as the difference between the post-polishing thickness of the wafer and the setting post-polishing thickness increases; c is the order value of the current wafer in the batch of wafers.

[0022] Optionally, the revised polishing time is obtained by the following formula:

[0023] Time(c+1) = R(c) / Rate …………………… (6)

[0024] In the formula, Time is the revised polishing time; R is the revised polishing thickness; Rate is the process parameter; and c is the order value of the current wafer in the batch of wafers.

[0025] Optionally, the process parameter is obtained by the following formula:

[0026] Rate = (Pre-Post) / Ti …………………… (7)

[0027] In the formula, Rate is the process parameter; Pre is the pre-polishing thickness, which is obtained by formula (1) or formula (2); Post is the post-polishing thickness, which is obtained by formula (3); and Ti is the setting polishing time.

[0028] Optionally, before the wafer polishing step is performed on the wafers in sequence, the following step is further included:

[0029] A machine test is performed on any of the wafers to be polished as a test wafer, and a wafer polishing step is performed on the test wafer according to the set process parameters; current data of the test wafer is obtained; the current data includes the pre-polishing thickness of the test wafer and the post-polishing thickness of the wafer;

[0030] According to formula (7), the process parameters are obtained.

[0031] Optionally, in the step of obtaining the current data of the wafer, only the pre-polishing thickness and the post-polishing thickness of part of the wafers in the batch are measured.

[0032] The present application has the following beneficial effects:

[0033] The wafer chemical mechanical planarization method provided by the present application obtains current data of the wafer, corrects the set process parameters in combination with historical data of the wafer, obtains a corrected polishing thickness and a corrected polishing time, and uses the corrected polishing thickness and the corrected polishing time for subsequent processes. At the same time, the current data is obtained multiple times, the set process parameters are corrected in combination with the historical data, and the grinding of the subsequent wafers is performed. In this way, the process parameters can be adjusted by multiple corrections in the same batch of wafers, so that the subsequent wafer polishing grinding results can be accurately corrected according to the different conditions of the wafers in the batch, and the variance of the polishing grinding results gradually decreases. The more the number of wafers in the batch, the more the number of corrections performed, the closer the wafers in the batch to the set target parameters, and the more the number of wafers close to the set target parameters, and the smaller the variance of the polishing grinding results.

[0034] Further, by reasonably allocating the weights of the historical data and the real-time data. After obtaining the real-time wafer feedback, the various parameters of the algorithm model are quickly fed back and iterated, and the real-time feedback information is stored in the database for subsequent calling of the model, so as to maximize the convergence speed of the new process. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0036] Figure 1 It is a structural schematic diagram of a chemical mechanical planarization device.

[0037] Figure 2 It is a flowchart of the wafer chemical mechanical planarization method of the present application;

[0038] Figure 3 A comparison chart of the polishing and grinding results of the wafer chemical mechanical planarization method of the present application for multiple batches of wafers. DETAILED DESCRIPTION

[0039] To solve the problem of large variance between polishing and grinding results in the chemical mechanical planarization process, the present application provides a wafer chemical mechanical planarization method. The wafer chemical mechanical planarization method of the present application comprises the following steps: providing a plurality of wafers to be polished; sequentially performing wafer polishing steps on the wafers according to set process parameters; the set process parameters include setting polishing thickness and setting polishing time; obtaining current data of the wafers during the wafer polishing process; the current data includes the pre-polishing thickness of the wafers and the post-polishing thickness of the wafers; providing historical data of wafer polishing steps; the historical data includes the historical pre-polishing thickness, the historical post-polishing thickness and the historical polishing time of all wafers before the current wafers; correcting the set process parameters according to the current data of the current wafers combined with the historical data to obtain corrected polishing thickness and corrected polishing time; performing polishing steps on the next wafers according to the corrected polishing thickness and the corrected polishing time; performing the step of obtaining current data of the wafers multiple times during the wafer polishing process, and obtaining corrected polishing thickness and corrected polishing time each time current data is obtained, and performing polishing steps on the next wafers according to the new corrected polishing thickness and the new corrected polishing time. Through the wafer chemical mechanical planarization method provided by the present application, the variance of the polishing and grinding results in the chemical mechanical planarization process can be reduced.

[0040] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal connection of two elements, or wireless connection, or wired connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0044] Embodiment

[0045] Reference Figure 1 And Figure 2 The present embodiment provides a wafer chemical planarization method. Polishing grinding is performed using a chemical planarization device as shown in Figure 1 , and a wafer thickness measurement device is additionally installed in Figure 1 , so as to obtain the pre-measurement thickness and the post-measurement thickness of the wafer through the wafer thickness measurement device.

[0046] The wafer chemical mechanical planarization method provided by the present embodiment comprises the following steps:

[0047] A plurality of wafers to be polished are provided.

[0048] According to the set process parameters, the wafer polishing step is sequentially performed on the wafers; the set process parameters include the set polishing thickness and the set polishing time.

[0049] During the wafer polishing process, the current data of the wafer is obtained; the current data includes the pre-polishing thickness of the wafer and the post-polishing thickness of the wafer.

[0050] The historical data of the wafer polishing step is provided; the historical data includes the historical pre-polishing thickness, the historical post-polishing thickness and the historical polishing time of all the wafers before the current wafer.

[0051] According to the current data of the current wafer, combined with the historical data, the set process parameters are corrected to obtain the corrected polishing thickness and the corrected polishing time.

[0052] According to the corrected polishing thickness and the corrected polishing time, the polishing step is performed on the next wafer.

[0053] In the wafer polishing process, the current data of the wafer is obtained multiple times, and each time the current data is obtained, the modified polishing thickness and the modified polishing time are obtained. The next wafer is polished according to the new modified polishing thickness and the new modified polishing time.

[0054] The wafer chemical mechanical planarization method provided by the embodiment obtains the current data of the wafer, corrects the set process parameters by combining the historical data of the wafer, obtains the modified polishing thickness and the modified polishing time, and uses the modified polishing thickness and the modified polishing time for subsequent processes. At the same time, the current data is obtained multiple times, and the set process parameters are corrected by combining the historical data to perform the polishing of the subsequent wafers. In this way, the process parameters can be adjusted by multiple corrections in the same batch of wafers, so that the variance of the polishing results of the subsequent wafers in the batch gradually decreases. The more the number of wafers in the batch, the more the number of corrections performed, the closer the wafers in the batch to the set target parameters, and the more the number of wafers close to the set target parameters, and the smaller the variance of the polishing results.

[0055] Further, in some embodiments, the obtaining of the current data of the wafer includes: collecting the pre-polishing thickness of each point on the wafer before polishing to obtain the pre-polishing thickness of each point; and the pre-polishing thickness of the wafer is calculated according to the following formula:

[0056] Pre=Average(P1,P2,P3,…,Pn)………………(1)

[0057] In the formula, Pre is the pre-polishing thickness of the wafer; P1,2, P3, …, n are the pre-polishing thicknesses of the points; and Average(P1,2, P3, …, n) is the average value of the pre-polishing thicknesses of the points. The average value is obtained by multiple point measurement, so that the obtained pre-polishing thickness of the wafer is closer to the actual required value.

[0058] In other embodiments, the obtaining of the current data of the wafer includes: the pre-polishing thickness of the wafer is calculated according to the following formula:

[0059] Pre=Average(Pre_n1,Pre_n2,…)......... (2)

[0060] In the formula, Pre is the pre-polishing thickness of the current wafer; Pre_n1, Pre_2,..., are the pre-polishing thicknesses of the first wafer, the second wafer,..., and the last wafer before the current wafer in the batch of wafers; and Average(Pre_n1, Pre_2,..., ) is the average of the pre-polishing thicknesses of the first wafer, the second wafer,..., and the last wafer before the current wafer in the batch of wafers. In some embodiments, the pre-polishing thickness of the current wafer is not measured in real time, but the pre-polishing thicknesses of several wafers before the current wafer in the batch of wafers are averaged to obtain the pre-polishing thickness of the current wafer. In this way, the pre-polishing thicknesses of some wafers are not measured, thereby saving the process and saving the process time.

[0061] In the present embodiment, the obtaining of the current data of the wafer comprises collecting the post-polishing thicknesses of the plurality of points on the wafer to obtain the post-polishing thickness of each point; and the post-polishing thickness of the wafer is calculated according to the following formula:

[0062] Post = Average(Post1, Post2, Post3,..., Postn) (3)

[0063] In the formula, Post is the post-polishing thickness of the current wafer; Post1, Post2, Post3,..., Postn are the post-polishing thicknesses of the plurality of points; and Average(Post1, Post2, Post3,..., Postn) is the average of the post-polishing thicknesses of the plurality of points. The post-polishing thickness of the wafer obtained by averaging the post-polishing thicknesses of the plurality of points is closer to the actual required value.

[0064] In the present embodiment, the corrected polishing thickness is calculated according to the following formula:

[0065] R(c) = (Pre - Pi + Ri) * (c) (4)

[0066] In the formula, R is the corrected polishing thickness; c is the sequence value of the current wafer in the batch of wafers; pre is the pre-polishing thickness of the current wafer, which is calculated according to formula (1) or formula (2); pi is the ideal pre-polishing thickness of the wafer, which is obtained according to the setting; Ri is the set polishing thickness, which is obtained according to the setting; and F is the total weight of the correction.

[0067] Specifically, in the present embodiment, the total weight of the correction is calculated according to the following formula:

[0068] F(c + 1) = w(c) * Y(c) + w(c - 1) * Y(c - 1) + w(c - 2) * Y(c - 2) (5)

[0069] wherein c is the order value of the current wafer in the batch of wafers; F is the sum of the correction weights; w is the order weight, w(c) is the order weight of the current wafer, w(c-1) is the order weight of the first previous wafer, w(c-2) is the order weight of the second previous wafer; w decreases as the distance from the current wafer increases. For example, the weight of the current measurement wafer result on the next wafer is 0.3, the weight of the first previous wafer result on the next wafer, i.e. the order weight w(c-1) is 0.2, the weight of the wafer closer to the current wafer is larger, and the weight of the wafer farther away is smaller. Y is the result weight, which is obtained according to the absolute value of the difference between the post-polishing thickness of the wafer and the set post-polishing thickness, and Y increases as the difference between the post-polishing thickness of the wafer and the set post-polishing thickness increases. For example, the thicker the thickness value of the cth wafer is from the ideal post-polishing value, the larger Y(c) is; on the contrary, if the thickness value of the cth wafer is thinner from the ideal post-polishing value, Y(c) is smaller.

[0070] Thus, the historical data and the real-time data are reasonably weighted. After obtaining the real-time wafer feedback, the various parameters of the algorithm model are quickly fed back and iterated, and the real-time feedback information is stored in the database for subsequent calling of the model, so as to maximize the convergence speed of the new process.

[0071] Further, the corrected polishing time is obtained by the following formula:

[0072] Time(c+1) = R(c) / Rate (6)

[0073] wherein c is the order value of the current wafer in the batch of wafers; Time is the corrected polishing time; R is the corrected polishing thickness; and Rate is the process parameter.

[0074] In the embodiment, the process parameter is obtained by the following formula:

[0075] Rate = (Pre-Post) / Ti (7)

[0076] wherein Rate is the process parameter; Pre is the pre-polishing thickness, which is obtained by formula (1) or formula (2); Post is the post-polishing thickness, which is obtained by formula (3); and Ti is the set polishing time.

[0077] Further, in some other embodiments, before the wafer is sequentially polished, the method further comprises the following steps:

[0078] The machine test takes any of the wafers to be polished as a test wafer, and performs a wafer polishing step on the test wafer according to the set process parameters; current data of the test wafer is obtained; the current data includes the pre-polishing thickness of the test wafer and the post-polishing thickness of the wafer;

[0079] According to formula (7), the process parameters are obtained.

[0080] Further, in the step of obtaining the current data of the wafer, only the pre-polishing thickness and the post-polishing thickness of part of the wafers in the batch are measured in the embodiment. Considering the input time and production efficiency of the correction process, only the pre-polishing thickness and the post-polishing thickness of part of the wafers are measured, and the correction is performed. A balance is achieved between reducing the variance and production efficiency. In some other embodiments, the pre-polishing thickness and the post-polishing thickness of each wafer in the batch can also be measured to obtain the smallest variance.

[0081] To show the variance reduction effect of the wafer chemical mechanical planarization method of the present application, five consecutive batches of wafers are taken, and the wafer chemical mechanical planarization method of the present application is used for polishing and grinding. The five batches are defined as lot1, lot2, lot3, lot4 and lot5 respectively. The process parameters Rate are obtained using the set polishing thickness and the set polishing time in lot1, and the subsequent lot2, lot3, lot4 and lot5 are sequentially polished and ground, and the process parameters Rate are obtained through formula (7). In formula (7), Pre and Post are replaced by the last obtained data in the previous batch, and Ti is replaced by the last obtained correction grinding time in the previous batch. As the process proceeds, the post-polishing thickness of each wafer is recorded, and the difference with the set target thickness is calculated. The curve of the above five batches of wafers is drawn with the difference as the vertical coordinate and the number of polished and ground wafers as the horizontal coordinate, as shown in Figure 3

[0082] According to Figure 3 ​As shown, the curves of lot1, lot2, lot3, lot4 and lot5 all converge to the same value, i.e. the polished thicknesses obtained after polishing and correction of the current data are more and more close to the set target thickness. At the same time, since the initial thicknesses of the wafers of different batches are different, the initial positions of the curves are different. Since lot1 uses the set polishing thickness and the set polishing time to obtain the Rate, the difference at the beginning of lot1 is large and the fluctuation is violent; with the increase of the number, the fluctuation decreases and gradually approaches a certain value, i.e. the variance of the results of the wafers of this batch is reduced. While lot2 to lot5, since the last obtained data Rate of the previous batch is used, due to the contribution of the wafers of the previous batch, the initial values of each batch are close to the ideal value, and all converge, i.e. the variance of the results of the wafers of each batch is reduced. In addition, the curve of lot4 converges upward because the pre-polishing thicknesses of wafers of different batches are slightly different. For example, the pre-polishing thickness of lot3 is thinner, so the feedback of lot3 before will be slightly more polished, so it will converge upward.

[0083] Obviously, the above embodiments are only examples for clearly illustrating, but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments do not need to be exhausted and it is impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A wafer chemical mechanical planarization method, characterized in that, Includes the following steps: Provide multiple wafers to be polished; According to the set process parameters, the wafer is sequentially subjected to wafer polishing steps; the set process parameters include setting polishing thickness and setting polishing time. During the wafer polishing process, current data of the wafer is acquired; the current data includes the wafer's thickness before polishing and the wafer's thickness after polishing. Provide historical data for wafer polishing steps; the historical data includes the historical pre-polishing thickness, historical post-polishing thickness, and historical polishing time of all wafers preceding the current wafer; Based on the current data of the current wafer and combined with the historical data, the set process parameters are corrected to obtain the corrected polishing thickness and corrected polishing time; Based on the modified polishing thickness and the modified polishing time, the next wafer is polished. During the wafer polishing process, the current data of the wafer is acquired multiple times. Each time the current data is acquired, a corrected polishing thickness and a corrected polishing time are obtained. Based on the new corrected polishing thickness and the new corrected polishing time, the next wafer is polished. The corrected polishing thickness is calculated using the following formula (4): …………（4） In the formula, To correct the polishing thickness; c is the order value of the wafer in this batch of wafers; The thickness of the wafer before polishing; The ideal pre-polishing thickness of the wafer is obtained according to a set parameter. The set polishing thickness is obtained according to the settings; To correct the total weight; The sum of the corrected weights is calculated using the following formula (5): （5） In the formula, c is the order value of the wafer in this batch of wafers; To correct the total weight; For order weights, The order weight of the current wafer. The order weight is based on the first wafer previously. The order weight is the same as the second wafer previously; From the current wafer onwards, it decreases as the number of wafers in the current wafer order increases; The result weight is obtained based on the absolute value of the difference between the polished thickness of the wafer and a set polished thickness. The value increases as the difference between the polished thickness and the set polished thickness increases.

2. The wafer chemical mechanical planarization method according to claim 1, characterized in that, The process of obtaining the current data of the wafer includes: collecting data from multiple points on the wafer before polishing to obtain the thickness of each point before polishing; The thickness of the wafer before polishing is calculated according to the following formula (1): ………（1） In the formula, The thickness of the wafer before polishing; These represent the thickness of each point before polishing; This represents the average thickness of each point before polishing.

3. The wafer chemical mechanical planarization method according to claim 1, characterized in that, The acquisition of the current data of the wafer includes: the thickness of the wafer before polishing is calculated by the following formula (2): .......（2） In the formula, The thickness of the wafer before polishing; These refer to the thickness of the current wafer before polishing, specifically the thickness of the first, second, ..., and last wafer in this batch of wafers. The average thickness of the current wafer before polishing is the same as that of the first, second, ..., last wafer in this batch of wafers.

4. The wafer chemical mechanical planarization method according to claim 2 or 3, characterized in that, The process of obtaining the current data of the wafer includes: collecting data from multiple points on the wafer after polishing to obtain the polished thickness of each point; The thickness of the wafer after polishing is calculated according to the following formula (3): ………（3） In the formula, The thickness of the wafer after polishing; The thickness after polishing at each point is shown below. This represents the average thickness after polishing at each point.

5. The wafer chemical mechanical planarization method according to claim 4, characterized in that, The corrected polishing time is calculated using the following formula (6): .......（6） In the formula, c is the order value of the wafer in this batch of wafers; The corrected polishing time; To correct the polishing thickness; These are process parameters.

6. The wafer chemical mechanical planarization method according to claim 5, characterized in that, The process parameters are calculated using the following formula (7): ..........（7） In the formula, These are the process parameters; The thickness before polishing is obtained by formula (1) or formula (2); The thickness after polishing is obtained by formula (3); Set the polishing time.

7. The wafer chemical mechanical planarization method according to claim 5, characterized in that, Before performing the wafer polishing step sequentially on the wafer, the following steps are also included: For machine testing, any wafer to be polished is selected as a test wafer, and a wafer polishing step is performed on the test wafer according to the set process parameters; the current data of the test wafer is obtained; the current data includes the thickness of the test wafer before polishing and the thickness of the wafer after polishing; The process parameters are obtained according to formula (7).

8. The wafer chemical mechanical planarization method according to claim 1, characterized in that, In the step of acquiring the current data of the wafer, the pre-polishing thickness and the post-polishing thickness of only a portion of the wafers in the batch are measured.

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