Chemical mechanical polishing processing method and device, equipment, storage medium

Abstract

The embodiment of the present application discloses a processing method and device, equipment, and storage medium for chemical mechanical polishing. In the technical solution of the present application, during the chemical mechanical polishing process, the target reflection coherence spectrum curve of the polishing layer of the wafer is first obtained, and then the target coherence extreme point and the wavelength corresponding to the target coherence extreme point are obtained according to the target reflection coherence spectrum curve, and then the actual thickness value of the polishing layer is determined according to the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness, and the target coherence extreme point. In the processing method for chemical mechanical polishing of the present application, by analyzing the relationship between the target reflection coherence spectrum curve and the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness and the target coherence extreme point, the actual thickness value of the polishing layer of the wafer can be effectively monitored with high accuracy.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of equipment for manufacturing semiconductor integrated circuit chips, and relate to but are not limited to a chemical mechanical polishing processing method and device, equipment, and storage medium. Background Art

[0002] Chemical Mechanical Polishing (CMP) is a key technology to achieve full flatness of silicon wafer surface. Its principle is a processing technology that combines chemical corrosion and mechanical removal. During the CMP polishing process, different polishing removal rates will cause different microscopic morphologies on the wafer surface, which is related to the process quality of CMP.

[0003] For the CMP process, under certain process parameters, there is an optimal polishing rate for grinding the thickness of the wafer polishing layer. At this time, the surface micro-roughness of the wafer is minimal. However, during the polishing process, the heat generated by friction, the crystallization and composition changes of the polishing liquid, and the morphological changes caused by the wear of the polishing pad will dynamically affect the thickness change of the polishing layer.

[0004] Therefore, how to effectively monitor the actual thickness value of the wafer polishing layer is an urgent problem to be solved. Summary of the invention

[0005] In view of this, the chemical mechanical polishing processing method, device, equipment, and storage medium provided in the embodiments of the present application can effectively monitor the actual thickness value of the wafer polishing layer. The chemical mechanical polishing processing method, device, equipment, and storage medium provided in the embodiments of the present application are implemented as follows:

[0006] The processing method of chemical mechanical polishing provided in an embodiment of the present application includes: in the chemical mechanical polishing process, obtaining a target reflection coherence spectrum curve of the polishing layer of the wafer; according to the target reflection coherence spectrum curve, obtaining a target coherence extreme point and a wavelength corresponding to the target coherence extreme point, wherein the target coherence extreme point indicates a peak or a trough in the target reflection coherence spectrum curve; according to a data set of a variation curve of the wavelength corresponding to a preset extreme point and the polishing layer thickness, and the target coherence extreme point, determining the actual thickness value of the polishing layer, wherein the data set of a variation curve of the wavelength corresponding to the preset extreme point and the polishing layer thickness includes a variation curve of the wavelength corresponding to the extreme point with the polishing layer thickness under different coherence levels.

[0007] In some embodiments, the actual thickness value of the polishing layer is determined based on a data set of curves of a wavelength corresponding to a preset extreme point and the thickness of the polishing layer, and the target coherent extreme point, including: determining the actual thickness value of the polishing layer based on the intersection of the wavelength corresponding to the target coherent extreme point and the data set of curves of a wavelength corresponding to the preset extreme point and the thickness of the polishing layer.

[0008] In some embodiments, the target coherent extreme point includes a first coherent extreme point and a second coherent extreme point, and the actual thickness value of the polishing layer is determined according to the intersection of the wavelength corresponding to the target coherent extreme point with the wavelength corresponding to the preset extreme point and the data set of the change curve of the polishing layer thickness, including: determining the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the wavelength corresponding to the preset extreme point and the data set of the change curve of the polishing layer thickness; determining the actual thickness value of the polishing layer according to the number of intersection points and the polishing layer thickness values ​​corresponding to the intersection points.

[0009] In some embodiments, the data set of change curves of the wavelength corresponding to the preset extreme point and the polishing layer thickness includes a first change curve of the wavelength corresponding to the extreme point and the polishing layer thickness when the extreme point is a peak at different coherence levels, and a second change curve of the wavelength corresponding to the extreme point and the polishing layer thickness when the extreme point is a trough at different coherence levels; determining the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the data set of change curves of the wavelength corresponding to the preset extreme point and the polishing layer thickness, includes: obtaining the indication of the peak or trough in the target reflection coherent spectrum curve indicated by the first coherent extreme point and the second coherent extreme point; determining the number of intersection points according to the indication; wherein the first coherent extreme point indicates a peak or a trough, and the second coherent extreme point indicates a peak or a trough.

[0010] In some embodiments, determining the actual thickness value of the polishing layer according to the number of the intersection points and the polishing layer thickness values ​​corresponding to the intersection points includes: when the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve, determining the number of the intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point with the first change curve and the intersection of the wavelength corresponding to the second coherent extreme point with the second change curve; when the number of intersection points between the wavelength corresponding to the first coherent extreme point and the first change curve is 1, or the number of intersection points between the wavelength corresponding to the second coherent extreme point and the second change curve is 1, determining the polishing layer thickness value corresponding to the intersection point as the actual thickness value of the polishing layer.

[0011] In some embodiments, the method also includes: when there are multiple intersection points between the wavelength corresponding to the first coherent extreme point and the first change curve, and when there are multiple intersection points between the wavelength corresponding to the second coherent extreme point and the second change curve, determining that the polishing layer thickness value corresponding to the intersection point of the wavelength corresponding to the first coherent extreme point and the first change curve is a first thickness value set, and the polishing layer thickness value corresponding to the intersection point of the wavelength corresponding to the second coherent extreme point and the second change curve is a second thickness value set; when there is only one pair of target intersection points in the first thickness value set and the second thickness value set that satisfy equal thickness values, determining the polishing layer thickness value corresponding to the target intersection point as the actual thickness value of the polishing layer.

[0012] In some embodiments, there are m coherent extreme points between the first coherent extreme point and the second coherent extreme point, where m is an integer, and the method further includes: when there are multiple pairs of target intersection points in the first thickness value set and the second thickness value set that satisfy equal thickness values, obtaining a first coherent series set and a second coherent series set according to the coherent series corresponding to the multiple pairs of target intersection points respectively; determining the polishing layer thickness value corresponding to the target intersection points in the first coherent series set and the second coherent series set that satisfy a preset coherent series relationship as the actual thickness value of the polishing layer, and the preset coherent series relationship is that the absolute value of the difference between the coherence series corresponding to the first coherent extreme point and the coherence series corresponding to the second coherent extreme point is equal to (m+1) / 2.

[0013] In some embodiments, the method further includes: when the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a peak in the target reflection coherent spectrum curve, determining the number of intersection points according to the intersection of the first change curve with the wavelength corresponding to the first coherent extreme point, and the wavelength corresponding to the second coherent extreme point; when the first coherent extreme point indicates a trough in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve, determining the number of intersection points according to the intersection of the second change curve with the wavelength corresponding to the first coherent extreme point, and the wavelength corresponding to the second coherent extreme point.

[0014] In some embodiments, before determining the actual thickness value of the polishing layer according to the data set of curves of the change of wavelength and polishing layer thickness corresponding to the preset extreme point and the target coherent extreme point, the method further includes: obtaining a plurality of standard reflection coherence spectrum curves, each of the plurality of standard reflection coherence spectrum curves corresponding to a different polishing layer thickness; obtaining the extreme value of each standard reflection coherence spectrum curve, the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve; obtaining the data set of curves of the change of wavelength and polishing layer thickness corresponding to the preset extreme point according to the extreme value of each standard reflection coherence spectrum curve, the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve.

[0015] In some embodiments, after determining the actual thickness value of the polishing layer based on the data set of the variation curve of the wavelength and the polishing layer thickness corresponding to the preset extreme point and the target coherent extreme point, the method further includes: obtaining the actual polishing rate of the wafer during the chemical mechanical polishing process; determining a target rate adjustment parameter based on the actual polishing rate and a preset standard polishing rate; and adjusting the polishing rate of the wafer based on the target rate adjustment parameter so that the actual polishing rate matches the standard polishing rate.

[0016] In some embodiments, the target rate adjustment parameters include a first adjustment parameter and a second adjustment parameter, the first adjustment parameter is obtained based on the ratio of a standard polishing rate to an actual polishing rate, and the second adjustment parameter is obtained based on the ratio of a difference between an actual polishing layer thickness value and a standard polishing layer thickness value to a preset multiple of the actual polishing rate; adjusting the polishing rate of the wafer according to the target rate adjustment parameters includes: adjusting subsequent equipment parameters of the chemical mechanical polishing equipment based on the first adjustment parameter and a current equipment parameter of the chemical mechanical polishing equipment, or based on the sum of the first adjustment parameter and the second adjustment parameter and the current equipment parameter of the chemical mechanical polishing equipment, so as to adjust the polishing rate of the wafer, the equipment parameters of the chemical mechanical polishing equipment include any one of the frequency of the polishing drive motor, the voltage of the polishing drive motor, and the input current of the pneumatic proportional solenoid valve.

[0017] The chemical mechanical polishing processing device provided in the embodiment of the present application includes: an acquisition module, which is used to acquire a target reflection coherence spectrum curve of a polishing layer of a wafer during a chemical mechanical polishing process; an analysis module, which is used to obtain a target coherence extreme point and a wavelength corresponding to the target coherence extreme point according to the target reflection coherence spectrum curve, wherein the target coherence extreme point indicates a peak or a trough in the target reflection coherence spectrum curve; a determination module, which is used to determine an actual thickness value of the polishing layer according to a data set of a variation curve of a wavelength corresponding to a preset extreme point and the polishing layer thickness, and the target coherence extreme point, wherein the data set of a variation curve of a wavelength corresponding to a preset extreme point and the polishing layer thickness includes a variation curve of a wavelength corresponding to an extreme point with the polishing layer thickness under different coherence levels.

[0018] The computer device provided in the embodiment of the present application includes a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, the chemical mechanical polishing processing method described in the embodiment of the present application is implemented.

[0019] The computer-readable storage medium provided in the embodiment of the present application stores a computer program thereon, and when the computer program is executed by a processor, the chemical mechanical polishing processing method provided in the embodiment of the present application is implemented.

[0020] The computer program product provided in the embodiment of the present application includes a computer program, which, when executed by a processor, implements the chemical mechanical polishing processing method provided in the embodiment of the present application.

[0021] In the chemical mechanical polishing processing method, device, equipment, and storage medium provided in the embodiments of the present application, during the chemical mechanical polishing process, the target reflection coherence spectrum curve of the polishing layer of the wafer is first obtained, and then the target coherence extreme point and the wavelength corresponding to the target coherence extreme point are obtained according to the target reflection coherence spectrum curve, and then the actual thickness value of the polishing layer is determined according to the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness, and the target coherence extreme point. In the chemical mechanical polishing processing method of the present application, by analyzing the relationship between the target reflection coherence spectrum curve and the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness and the target coherence extreme point, the actual thickness value of the polishing layer of the wafer can be effectively monitored with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and are used together with the specification to illustrate the technical solution of the present application.

[0023] Figure 1 A schematic diagram of the application principle of the chemical mechanical polishing method provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of reflected light interference provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of a process flow for implementing a chemical mechanical polishing method provided in one embodiment of the present application;

[0026] Figure 4 A schematic diagram of a target reflection coherent spectrum curve provided by one embodiment of the present application;

[0027] Figure 5 A schematic diagram of the extreme point calibration of the target reflection coherent spectrum curve provided by one embodiment of the present application;

[0028] Figure 6 A schematic diagram of a data set of a variation curve of wavelength and polishing layer thickness corresponding to a preset extreme point provided by an embodiment of the present application;

[0029] Figure 7 A schematic diagram of a process flow of implementing a chemical mechanical polishing method provided in another embodiment of the present application;

[0030] Figure 8 A schematic diagram of the intersection of a wavelength corresponding to a target coherent extreme point, a wavelength corresponding to a preset extreme point, and a data set of a variation curve of a polishing layer thickness provided in one embodiment of the present application;

[0031] Fig. 9A schematic diagram of an actual polishing layer thickness variation curve and a standard polishing layer thickness variation curve provided for one embodiment of the present application;

[0032] Fig.10 A structural schematic diagram of a chemical mechanical polishing processing device provided in one embodiment of the present application;

[0033] Fig.11 A structural schematic diagram of a computer device provided for one embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0036] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0037] It should be pointed out that the terms "first\second\third" involved in the embodiments of the present application are used to distinguish similar or different objects, and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0038] Chemical Mechanical Polishing (CMP) is a key technology to achieve full flatness of silicon wafer surface. Its principle is a processing technology that combines chemical corrosion and mechanical removal. During the CMP polishing process, different polishing removal rates will cause different microscopic morphologies on the wafer surface, which is related to the process quality of CMP.

[0039] For example, see Figure 1 , Figure 1 A schematic diagram of the application principle of the chemical mechanical polishing method provided in the embodiment of the present application; Figure 1 In the embodiment, the chemical mechanical polishing processing system includes an optical unit 20 , an analysis and calculation unit 30 , and a computer system unit 40 .

[0040] First, the optical unit 20 is used to emit a stable continuous incident light beam to illuminate the polished surface of the wafer 10, and receive the reflected characteristic coherent light beam generated by the polished surface of the wafer 10, and then collect and obtain the corresponding reflected coherent spectrum data and transmit it to the analysis and calculation unit 30. The incident light beam has a certain wavelength range. The optical unit 20 contains a related optical sensor, which can convert the reflected light beam into an analog electrical signal form to obtain the corresponding reflected coherent spectrum data.

[0041] The analysis and calculation unit 30 analyzes the obtained reflection coherent spectrum data in combination with the data set of the variation curve of the wavelength and the polishing layer thickness corresponding to the preset extreme point stored in the computer system unit 40, and outputs the analysis result to the computer system unit 40.

[0042] The computer system unit 40 includes a storage unit and a driving unit. The storage unit stores data such as a data set of a change curve of wavelength and polishing layer thickness corresponding to a preset extreme point. After receiving the analysis result of the analysis and calculation unit 30, the driving unit changes the CMP equipment parameters based on the analysis result to control the polishing rate.

[0043] Furthermore, the polished surface of the wafer 10 includes an oxide light-transmitting layer (Ox light-transmitting layer) and a silicon substrate layer (Si substrate layer), see Figure 2 , Figure 2 Schematic diagram of reflected light interference provided in the embodiment of the present application. Figure 2 As shown, the incident light beam irradiates the polished surface of the wafer 10, and two beams of reflected light are generated. One beam is the reflected light generated by the interface between the air and the oxide transparent layer, and the intensity is I A ; A beam of reflected light generated at the interface between the oxide light-transmitting layer and the silicon substrate layer, with an intensity of I B Since the intensity is I B The reflected light passes through the oxide transparent layer and is reflected by the silicon substrate layer, and the intensity is I A There is an optical path difference between the reflected light , the two reflected lights will interfere with each other, thus forming a reflection coherent spectrum. Assuming the refractive index of the oxide light-transmitting layer is n, the optical path difference formula is , then the coherence formula (1) of the reflection coherence spectrum curve satisfies:

[0044] (Formula 1)

[0045] Where d is the current thickness of the oxide light-transmitting layer, is the wavelength in the reflectance coherence spectrum curve.

[0046] Among them, in the reflection coherence spectrum, when the optical path difference satisfies When the optical path difference satisfies When , the interference is destructive; where N is the coherence series, which can be integers 1, 2, 3, etc. is the wavelength of the coherence peak, is the wavelength of the interference trough, and the coherence order decreases from left to right as the wavelength increases.

[0047] For the CMP process, under certain process parameters, there is an optimal polishing rate for grinding the thickness of the wafer polishing layer. At this time, the surface micro-roughness of the wafer is minimal. However, during the polishing process, the heat generated by friction, the crystallization and composition changes of the polishing liquid, and the morphological changes caused by the wear of the polishing pad will dynamically affect the thickness change of the polishing layer.

[0048] Therefore, how to effectively monitor the actual thickness value of the wafer polishing layer is an urgent problem to be solved.

[0049] In view of this, an embodiment of the present application provides a processing method for chemical mechanical polishing, which specifically includes: in the chemical mechanical polishing process, first obtaining a target reflection coherent spectrum curve of the polishing layer of the wafer, and then obtaining a target coherent extreme point and a wavelength corresponding to the target coherent extreme point according to the target reflection coherent spectrum curve, and then determining the actual thickness value of the polishing layer according to a data set of a change curve of the wavelength corresponding to the preset extreme point and the thickness of the polishing layer, and the target coherent extreme point. In the processing method for chemical mechanical polishing of the present application, by analyzing the relationship between the target reflection coherent spectrum curve and the data set of a change curve of the wavelength corresponding to the preset extreme point and the thickness of the polishing layer and the target coherent extreme point, the actual thickness value of the polishing layer of the wafer can be effectively monitored with high accuracy.

[0050] In order to make the purpose and technical solution of the present application clearer and more intuitive, the following will be combined with the accompanying drawings and embodiments to describe in detail the chemical mechanical polishing method, device, equipment, and storage medium provided in the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] It should be noted that the execution subject of the embodiment of the present application can be a chemical mechanical polishing device, or a chemical mechanical polishing processing device, or an independent electronic device (such as a terminal device), and the present application does not make specific limitations. The embodiment of the present application can be implemented during the chemical mechanical polishing process, and can also be implemented while performing optical endpoint monitoring.

[0052] Please refer to Figure 3 , is a schematic diagram of the implementation process of the chemical mechanical polishing method provided by one embodiment of the present application. Figure 3 As shown, the method may include the following steps 301 to 303:

[0053] Step 301 : acquiring a target reflection coherent spectrum curve of a polishing layer of a wafer during chemical mechanical polishing.

[0054] In some embodiments, the target reflection coherence spectrum curve can be obtained by Figure 1 The optical unit 20 collects, combined with Figure 1 As shown, after the incident light beam is irradiated onto the polished surface of the wafer 10, a beam of reflected light is generated at the interface between the air and the oxide light-transmitting layer, with an intensity of I A The incident light beam passes through the oxide light-transmitting layer and is reflected by the silicon substrate layer, generating another beam of reflected light with an intensity of I B The intensity is I A The reflected light with intensity I B There is an optical path difference between the reflected lights, and the two reflected lights will interfere with each other to form a reflective characteristic coherent light beam. The optical unit 20 collects the reflective coherent spectrum data during the CMP process in real time and transmits it to the analysis and calculation unit 30 for fitting to obtain the reflective coherent spectrum curve.

[0055] Optionally, the collected target reflection coherence spectrum curve corresponds to a preset wavelength range, which can be the wavelength range of the incident light beam or a part of the wavelength range of the incident light beam; further, the preset wavelength range can also be the wavelength range corresponding to sampling data with a higher signal-to-noise ratio in the real-time collected reflection coherence spectrum curve, and the present application does not limit this.

[0056] In some embodiments, the target reflection coherent spectrum curve can be directly fitted based on the collected coherent spectrum data of the wafer, or it can be calculated based on the collected coherent spectrum data of the wafer combined with the reflected light coherence principle formula, that is, the above formula (1), and this application does not limit this.

[0057] For example, please refer to Figure 4 , is a schematic diagram of a target reflection coherent spectrum curve provided by an embodiment of the present application. Figure 4 As shown, the horizontal axis is the wavelength in nm, and the vertical axis is the intensity of light. The target reflection coherent spectrum curve includes multiple peaks and troughs.

[0058] Step 302: Obtain target coherent extreme value points and wavelengths corresponding to the target coherent extreme value points according to the target reflection coherent spectrum curve, wherein the target coherent extreme value points indicate peaks or troughs in the target reflection coherent spectrum curve.

[0059] In some embodiments, after obtaining the target reflection coherence spectrum curve, the extreme points of the target reflection coherence spectrum curve can be calibrated, that is, the peak position and the trough position in the target reflection coherence spectrum curve are calibrated, and the target coherence extreme point is selected from the extreme points.

[0060] For example, please refer to Figure 5 , is a schematic diagram of the extreme point calibration of the target reflection coherent spectrum curve provided by an embodiment of the present application. Figure 5 As shown, the extreme points are calibrated at the peak position and the trough position in the target reflection coherent spectrum curve, where the target coherent extreme point can be Figure 5 The wavelength shown in and The position on the target reflectance coherence spectrum curve.

[0061] Step 303, determine the actual thickness value of the polishing layer based on the wavelength corresponding to the preset extreme point and the polishing layer thickness change curve data set, and the target coherent extreme point. The wavelength corresponding to the preset extreme point and the polishing layer thickness change curve data set include the wavelength corresponding to the extreme point and the polishing layer thickness change curve under different coherence levels.

[0062] In some embodiments, the wavelength corresponding to the preset extreme point and the polishing layer thickness change curve data set can be obtained by collecting multiple standard reflection coherence spectrum curves, each of the multiple standard reflection coherence spectrum curves corresponds to a different polishing layer thickness (preparing multiple standard samples with different polishing layer thicknesses in advance), or, by theoretically calculating multiple standard reflection coherence spectrum curves corresponding to different polishing layer thicknesses, and then obtaining them based on the extreme value of each standard reflection coherence spectrum curve, the wavelength corresponding to the extreme value of each standard reflection coherence spectrum curve, and the coherence order.

[0063] In some embodiments, when the standard reflection coherence spectrum curve takes extreme values ​​(peaks and valleys), the formula is satisfied. , where d is the polishing layer thickness, K is the coherence order, is the wavelength corresponding to the extreme point, and n is the refractive index. Since the refractive index changes slightly with wavelength, it can be assumed to be a constant.

[0064] When the wavelength corresponding to the extreme point is the peak, K=N is satisfied. When the wavelength corresponding to the extreme point is the trough, K=N-0.5 is satisfied. N is a positive integer. As chemical mechanical polishing proceeds, the thickness of the oxide light-transmitting layer decreases, and the wavelengths of the coherent peaks of the same order N decrease synchronously, resulting in the formula , then the wavelength corresponding to the extreme point is There is a proportional linear relationship with the polishing layer thickness d.

[0065] For example, please refer to Figure 6 , is a schematic diagram of a curve data set of a wavelength and a polishing layer thickness change corresponding to a preset extreme point provided in an embodiment of the present application, such as Figure 6As shown, the corresponding curves when K=1, K=2, K=3, and K=4 are the changing curves of the wavelength corresponding to the extreme point and the thickness of the polishing layer when the extreme point is a peak; the corresponding curves when K=0.5, K=1.5, K=2.5, and K=3.5 are the changing curves of the wavelength corresponding to the extreme point and the thickness of the polishing layer when the extreme point is a trough.

[0066] Furthermore, based on the positional relationship between the wavelength corresponding to the target coherent extreme point and the wavelength corresponding to the preset extreme point and the data set of the variation curve of the polishing layer thickness, the wavelength corresponding to the target coherent extreme point can be inserted into the data set of the variation curve of the wavelength corresponding to the preset extreme point and the polishing layer thickness, and the actual thickness value of the polishing layer can be calculated by analysis and comparison.

[0067] In this embodiment, during the chemical mechanical polishing process, the target reflection coherent spectrum curve of the polishing layer of the wafer is first obtained, and then the target coherent extreme point and the wavelength corresponding to the target coherent extreme point are obtained according to the target reflection coherent spectrum curve, and then the actual thickness value of the polishing layer is determined according to the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness, and the target coherent extreme point. In the chemical mechanical polishing processing method of the present application, by analyzing the relationship between the target reflection coherent spectrum curve and the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness and the target coherent extreme point, the actual thickness value of the wafer polishing layer can be effectively monitored with high accuracy.

[0068] Based on the above embodiments, Figure 7 A schematic diagram of a process flow of chemical mechanical polishing according to another embodiment of the present invention is shown in FIG. Figure 7 As shown, the method may include the following steps 701 to 707:

[0069] Step 701 : acquiring a target reflection coherent spectrum curve of a polishing layer of a wafer during chemical mechanical polishing.

[0070] In some embodiments, the target reflection coherent spectrum curve can be directly fitted based on the collected coherent spectrum data of the wafer, or it can be calculated based on the collected coherent spectrum data of the wafer combined with the reflected light coherence principle formula, that is, the above formula (1), and this application does not limit this.

[0071] Step 702, according to the target reflection coherent spectrum curve, obtain the target coherent extreme value point and the wavelength corresponding to the target coherent extreme value point, the target coherent extreme value point indicates the peak or trough in the target reflection coherent spectrum curve.

[0072] In some embodiments, after obtaining the target reflection coherence spectrum curve, the extreme points of the target reflection coherence spectrum curve can be calibrated, that is, the peak position and the trough position in the target reflection coherence spectrum curve are calibrated, and the target coherence extreme point is selected from the extreme points.

[0073] Step 703, obtaining a data set of a change curve of wavelength and polishing layer thickness corresponding to a preset extreme point.

[0074] In some embodiments, a plurality of standard reflection coherence spectrum curves are first obtained, each of the plurality of standard reflection coherence spectrum curves corresponding to a different polishing layer thickness, and then the extreme value of each standard reflection coherence spectrum curve, the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve are obtained, and finally, based on the extreme value of each standard reflection coherence spectrum curve, the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve, a data set of curves of changes in wavelength and polishing layer thickness corresponding to a preset extreme point is obtained.

[0075] Step 704 , determining the actual thickness value of the polishing layer according to the intersection of the wavelength corresponding to the target coherent extreme point, the wavelength corresponding to the preset extreme point, and the polishing layer thickness variation curve data set.

[0076] It should be noted that the preset data set of the variation curves of the wavelength corresponding to the extreme point and the polishing layer thickness includes the variation curves of the wavelength corresponding to the extreme point and the polishing layer thickness under different coherence orders.

[0077] In some embodiments, the target coherent extreme point includes a first coherent extreme point and a second coherent extreme point. The number of intersection points can be determined based on the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the wavelength corresponding to the preset extreme point and the data set of the change curve of the polishing layer thickness, and then the actual thickness value of the polishing layer can be determined based on the number of intersection points and the polishing layer thickness values ​​corresponding to the intersection points.

[0078] It should be noted that the number of target coherent extreme value points may be one, two or more, and this application does not limit this. In the embodiment of this application, the target coherent extreme value points include the first coherent extreme value point and the second coherent extreme value point as an example for description.

[0079] In a possible implementation, the preset data set of the change curves of the wavelength and the polishing layer thickness corresponding to the extreme point includes a first change curve of the wavelength and the polishing layer thickness corresponding to the extreme point when the coherence order is different and the extreme point is a peak, and a second change curve of the wavelength and the polishing layer thickness corresponding to the extreme point when the coherence order is different and the extreme point is a trough. Figure 6As shown, the corresponding curves when K=1, K=2, K=3, and K=4 are the change curves of the wavelength and the thickness of the polishing layer corresponding to the extreme value point when the extreme value point is a peak, that is, the first change curve; the corresponding curves when K=0.5, K=1.5, K=2.5, and K=3.5 are the change curves of the wavelength and the thickness of the polishing layer corresponding to the extreme value point when the extreme value point is a trough, that is, the second change curve.

[0080] Furthermore, the indication of the peaks or troughs in the target reflection coherent spectrum curve indicated by the first coherent extreme point and the second coherent extreme point is obtained; then, according to the indication, the number of intersection points is determined; wherein, the first coherent extreme point indicates a peak or a trough, and the second coherent extreme point indicates a peak or a trough.

[0081] Among them, when the indication situation is that the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve, the number of intersection points is determined according to the intersection of the wavelength corresponding to the first coherent extreme point and the first change curve, and the intersection of the wavelength corresponding to the second coherent extreme point and the second change curve.

[0082] When the indication situation is that the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a peak in the target reflection coherent spectrum curve, the number of intersection points is determined according to the intersection of the first change curve with the wavelength corresponding to the first coherent extreme point, and the wavelength corresponding to the second coherent extreme point.

[0083] When the indication situation is that the first coherent extreme point indicates a trough in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve, the number of intersection points is determined according to the intersection of the second change curve with the wavelength corresponding to the first coherent extreme point, and the wavelength corresponding to the second coherent extreme point.

[0084] As an example, the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve. Figure 5 The wavelength shown in The position on the target reflection coherent spectrum curve is at the peak; the second coherent extreme point is Figure 5 The wavelength shown in The position on the target reflection coherent spectrum curve is at the trough, then K i , K j is the corresponding coherence series, assuming , is the coherence series difference, we can get ,exist If the actual thickness d of the polishing layer is known, the unique actual thickness d of the polishing layer can be analyzed through the data set of the variation curve of the wavelength and the polishing layer thickness corresponding to the preset extreme point.

[0085] Furthermore, the wavelength corresponding to the first coherent extreme point is The wavelength corresponding to the second coherence extreme point insert Figure 6 In the data set of the variation curves of the wavelength corresponding to the preset extreme point and the polishing layer thickness, the wavelength corresponding to the first coherent extreme point is The number of intersection points with the first variation curve is 1, or the wavelength corresponding to the second coherent extreme point When the number of intersection points with the second variation curve is 1, the polishing layer thickness value corresponding to the intersection point is determined as the actual thickness value of the polishing layer.

[0086] When there are multiple intersection points between the wavelength corresponding to the first coherent extreme point and the first change curve, and there are multiple intersection points between the wavelength corresponding to the second coherent extreme point and the second change curve, the polishing layer thickness value corresponding to the intersection point of the wavelength corresponding to the first coherent extreme point and the first change curve is determined to be a first thickness value set, and the polishing layer thickness value corresponding to the intersection point of the wavelength corresponding to the second coherent extreme point and the second change curve is determined to be a second thickness value set. When there is only one pair of target intersection points in the first thickness value set and the second thickness value set that satisfy equal thickness values, the polishing layer thickness value corresponding to the target intersection point is determined to be the actual thickness value of the polishing layer.

[0087] For example, in the above Figure 6 The preset extreme points shown correspond to the wavelength and polishing layer thickness variation curve data set, please refer to Figure 8 , which is a schematic diagram of the intersection of the wavelength corresponding to the target coherent extreme point and the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness provided by an embodiment of the present application, such as Figure 8 As shown, assuming that the wavelength corresponding to the first coherent extreme point is (Take the first coherent extreme point indicating the peak as an example, see Figure 5 ) has multiple intersections with the first variation curve, that is, the wavelength corresponding to the first coherent extreme point The thickness value corresponding to the intersection of the first variation curve corresponding to K=1 is d1, and the wavelength corresponding to the first coherent extreme point is The thickness value corresponding to the intersection of the first variation curve corresponding to K=2 is d2, that is, the first thickness value set includes d1 and d2; assuming that the wavelength corresponding to the second coherent extreme point is (Take the second coherent extreme point indicating the trough as an example, see Figure 5) has multiple intersections with the second variation curve, that is, the wavelength corresponding to the second coherent extreme point The thickness value corresponding to the intersection point of the second change curve corresponding to K=0.5 is d1, that is, the second thickness value set includes d1; then d1 exists in both the first thickness value set and the second thickness value set, that is, there is a pair of target intersection points that satisfy equal thickness values, and therefore the polishing layer thickness value d1 corresponding to the target intersection point is determined to be the actual thickness value of the polishing layer.

[0088] In some embodiments, assuming that there are m coherent extreme points between the first coherent extreme point and the second coherent extreme point, where m is an integer, when there are multiple pairs of target intersection points in the first thickness value set and the second thickness value set that satisfy equal thickness values, the first coherent series set and the second coherent series set are obtained according to the coherent series corresponding to the multiple pairs of target intersection points respectively; the polishing layer thickness values ​​corresponding to the target intersection points in the first coherent series set and the second coherent series set that satisfy a preset coherent series relationship are determined as the actual thickness values ​​of the polishing layer, and the preset coherent series relationship is that the absolute value of the difference between the coherence series corresponding to the first coherent extreme point and the coherence series corresponding to the second coherent extreme point is equal to (m+1) / 2.

[0089] For example, assuming that the wavelength corresponding to the first coherent extreme point is There are multiple intersections with the first change curve, corresponding to the coherence series (K1, K2...), that is, the first coherence series set, and the wavelength corresponding to the second coherence extreme point There are multiple intersection points in the second change curve, corresponding to coherence series (K1', K2'...), that is, the second coherence series set, among which only one pair of target intersection points satisfies that the absolute value of the difference in coherence series is equal to (m+1) / 2, then the d value coordinate corresponding to the target intersection point is the actual thickness value of the polishing layer.

[0090] It should be noted that, when the indication situation is that the first coherent extreme point indicates a peak in the target reflection coherence spectrum curve, and the second coherent extreme point indicates a peak in the target reflection coherence spectrum curve, and when the indication situation is that the first coherent extreme point indicates a trough in the target reflection coherence spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherence spectrum curve, the method for obtaining the actual thickness value of the polishing layer is the same as above, and this application will not repeat it here.

[0091] Optionally, the selection of the target coherent extreme point can give priority to the extreme point with a larger corresponding wavelength value, such as the wavelength with the largest value. At this time, the number of intersection points of the target coherent extreme point and the wavelength corresponding to the preset extreme point and the polishing layer thickness change curve data set is small, and the actual thickness value of the polishing layer can be analyzed more quickly.

[0092] Step 705 , obtaining an actual polishing rate of the wafer during the chemical mechanical polishing process.

[0093] In some embodiments, an implementation method for obtaining the actual polishing rate of the polishing layer of the wafer is: during the chemical mechanical polishing process, the polishing layer of the wafer is sampled multiple times to obtain multiple target reflection coherent spectrum curves of the polishing layer of the wafer, and the corresponding polishing layer thickness is obtained respectively; then, according to the multiple polishing layer thicknesses and the time interval between the multiple samplings, the actual polishing layer thickness change curve is obtained; and then the actual polishing rate is obtained by derivation of the actual polishing layer thickness change curve. Among the multiple polishing layer thicknesses, the thickness with the largest value is the initial polishing layer thickness, and the sampling time corresponding to the initial polishing layer thickness is the initial time.

[0094] In some embodiments, according to the relationship between the actual thickness value of the polishing layer and the time, a curve of the actual polishing layer thickness change of the wafer within a preset time period can be fitted.

[0095] Exemplarily, after the start of the polishing process, when the actual thickness of the polishing layer is obtained through steps 701 to 704, the actual thickness value of the polishing layer can be set to an initial polishing layer thickness value d0, and the sampling time can be used as the initial time t0. Furthermore, within a preset time period Δt after the initial time t0, a new measured reflection coherence spectrum of the wafer polishing layer will be continuously obtained, and further analyzed, that is, the above steps 701 to 704 are repeated to obtain the actual thickness of the polishing layer corresponding to the newly collected measured reflection coherence spectrum curve, and then the actual polishing layer thickness change curve of the wafer within the preset time period is obtained.

[0096] It can be understood that the initial time t0 in this scheme reflects the actual implementation time of the polishing process, and the specific value can be assigned any value. Among them, multiple samples can be taken within the preset time period Δt to obtain multiple actual thicknesses of the polishing layer, and the time intervals between different samples are recorded, so that the actual polishing layer thickness change curve e(t) can be obtained by fitting, and the first-order derivative operation of the actual polishing layer thickness change curve is performed to obtain the actual polishing rate v=e'(t).

[0097] Step 706, determining a target rate adjustment parameter according to the actual polishing rate and a preset standard polishing rate.

[0098] In some embodiments, the target rate adjustment parameter includes a first adjustment parameter and a second adjustment parameter. Further, according to the actual polishing rate and the preset standard polishing rate, one implementation method for determining the target rate adjustment parameter is: according to the initial polishing layer thickness, obtaining the mapping relationship between the standard polishing layer thickness change curve and the actual polishing layer thickness change curve; then obtaining the mapped standard polishing layer thickness change curve according to the mapping relationship, and taking the derivative of the mapped standard polishing layer thickness change curve to obtain the standard polishing rate; then obtaining the first adjustment parameter according to the actual polishing rate and the standard polishing rate, and obtaining the thickness deviation value at any time after the initial time according to the mapped standard polishing layer thickness change curve and the actual polishing layer thickness change curve, and obtaining the second adjustment parameter based on the thickness deviation value and the actual polishing rate.

[0099] It should be understood that, based on experience, a standard polishing layer thickness variation curve f(x) of CMP under an optimal working state can be obtained in advance.

[0100] In some embodiments, by comparing the actual polishing rate with a preset standard polishing rate, the polishing rate deviation value can be obtained, and then the adjustment variable of the polishing process, that is, the target rate adjustment parameter, can be calculated.

[0101] Substitute the initial polishing layer thickness value d0 in the above step into the standard polishing layer thickness change curve f(x) to obtain the standard initial time x0. Thus, the mapping relationship between the actual polishing layer thickness change curve e(t) and the standard polishing layer thickness change curve f(x) is established through the initial polishing layer thickness value d0, and t0=x0+c is set, then there is an arbitrary monitoring time point t=x+c. It can be understood that although the initial time t0 of the actual implementation time of the feedback polishing process can be assigned any value, it is only necessary to determine the initial polishing layer thickness value d0 to establish the mapping relationship between the actual polishing layer thickness change curve e(t) and the standard polishing layer thickness change curve f(x), so that the difference between the actual polishing thickness and the standard polishing thickness can be synchronously compared. For any time t, the corresponding actual polishing layer thickness value is e(t), and the corresponding standard polishing thickness value obtained according to the mapping relationship is f(x)=f(tc), where c is the mapping constant.

[0102] In some embodiments, the target rate adjustment parameter includes a first adjustment parameter, which is obtained based on the ratio of the standard polishing rate to the actual polishing rate. The first adjustment parameter is obtained based on the deviation between the actual polishing rate v and the standard polishing rate u. .

[0103] In some embodiments, the target rate adjustment parameter includes a first adjustment parameter and a second adjustment parameter, wherein the second adjustment parameter is obtained according to the ratio of the difference between the actual polishing layer thickness value and the standard polishing layer thickness value to the actual polishing rate of a preset multiple.

[0104] For example, at time t, the actual polishing layer thickness value is e(t), and according to the mapping relationship, the time point corresponding to the standard polishing layer thickness change curve is x=tc, and the corresponding standard polishing layer thickness value is f(x)=f(tc), and the corresponding thickness deviation value Δd=g(t)= e(t)-f(tc). Fig. 9 As shown, Fig. 9 The figure includes the actual polishing layer thickness variation curve and the standard polishing layer thickness variation curve, as well as a schematic diagram of time point mapping.

[0105] Further, according to the thickness deviation value of the actual polishing layer thickness value and the standard polishing layer thickness value, the second adjustment parameter is obtained. , where k is a set value, which can be set manually. The larger the k value is, the higher the output When the k value is infinite, the second adjustment parameter is not output. =0.

[0106] Step 707, adjusting the polishing rate of the wafer according to the target rate adjustment parameters, so that the actual polishing rate is consistent with the standard polishing rate.

[0107] In some embodiments, according to the first adjustment parameter and the current equipment parameter of the chemical mechanical polishing equipment, or according to the sum of the first adjustment parameter and the second adjustment parameter and the current equipment parameter of the chemical mechanical polishing equipment, the subsequent equipment parameter of the chemical mechanical polishing equipment is adjusted to adjust the polishing rate of the wafer, and the equipment parameter of the chemical mechanical polishing equipment includes any one of the frequency of the polishing drive motor, the voltage of the polishing drive motor, and the input current of the pneumatic proportional solenoid valve. The polishing drive motor is used to drive the CMP equipment polishing head to rotate, and the pneumatic proportional solenoid valve is used to adjust the pressure of the internal chamber of the polishing head to change the polishing pressure of the polished sample.

[0108] Optionally, when the equipment parameter of the chemical mechanical polishing equipment is the frequency of the polishing drive motor, it is known that the polishing rate is proportional to the speed of the polishing drive motor, and the polishing rate is dynamically adjusted by changing the speed of the polishing drive motor ω, the motor speed ω is proportional to the motor speed drive parameter (voltage or alternating frequency) F, and the motor speed ω is proportional to the polishing rate, and the adjusted motor drive parameter is F'=F*(a+β). Optionally, the motor drive parameter can also be adjusted based on the first adjustment parameter to obtain the adjusted motor drive parameter F'=F*a.

[0109] Optionally, when the equipment parameter of the chemical mechanical polishing equipment is the input current of the pneumatic proportional solenoid valve, the polishing rate is dynamically adjusted by changing the polishing pressure P, wherein the polishing pressure P is achieved by controlling the air pressure of the proportional solenoid valve, and is proportional to the control current of the proportional solenoid valve, and the polishing pressure is also proportional to the polishing rate, so the adjusted proportional solenoid valve control current I'=I*(a+β). Optionally, the motor drive parameter can be adjusted based on the first adjustment parameter to obtain the adjusted motor drive parameter I'=I*a.

[0110] Optionally, adjusting the polishing rate of the wafer according to the target rate adjustment parameters can be achieved by setting up a separate control logic unit to dynamically adjust the actual polishing rate to meet the standard polishing rate so that the actual polishing rate is within an ideal range of variation.

[0111] In this embodiment, during the chemical mechanical polishing process, the target reflection coherence spectrum curve of the polishing layer of the wafer is first obtained, and then the target coherence extreme point and the wavelength corresponding to the target coherence extreme point are obtained based on the target reflection coherence spectrum curve, and then the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness are obtained, and the actual thickness value of the polishing layer is determined based on the intersection of the wavelength corresponding to the target coherence extreme point and the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness. Furthermore, during the chemical mechanical polishing process, the actual polishing rate of the wafer is obtained, and the target rate adjustment parameter is determined based on the actual polishing rate and the preset standard polishing rate, and the polishing rate of the wafer is adjusted based on the target rate adjustment parameter so that the actual polishing rate matches the standard polishing rate. By analyzing the target reflection coherent spectrum curve and the relationship between the wavelength corresponding to the preset extreme point and the polishing layer thickness change curve data set and the target coherent extreme point, the actual thickness value of the wafer polishing layer can be effectively monitored with high accuracy; when controlling the polishing rate, unlike the existing methods of monitoring friction and monochromatic light intensity in related technologies, the relative change of the wafer polishing layer thickness is directly measured, the value is accurate and reliable, and is not affected by other process factors. Finally, according to the distribution curve of the polishing rate difference, the polishing process parameters are dynamically controlled and adjusted to make the polishing speed within the ideal range of variation, thereby improving the quality of the CMP polishing process.

[0112] It should be understood that, although the steps in the above-mentioned flowcharts are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the above-mentioned flowcharts may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0113] Based on the foregoing embodiments, an embodiment of the present application provides a chemical mechanical polishing processing device, which includes the modules included and the units included in the modules, which can be implemented by a processor; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit, a microprocessor, a digital signal processor or a field programmable gate array, etc.

[0114] Fig.10 A structural schematic diagram of a chemical mechanical polishing processing device provided in one embodiment of the present application is shown as follows: Fig.10 As shown, the device 1000 includes an acquisition module 1001, an analysis module 1002 and a determination module 1003, wherein:

[0115] An acquisition module 1001 is used to acquire a target reflection coherence spectrum curve of a polishing layer of a wafer during a chemical mechanical polishing process; an analysis module 1002 is used to obtain a target coherence extreme point and a wavelength corresponding to the target coherence extreme point according to the target reflection coherence spectrum curve, wherein the target coherence extreme point indicates a peak or a trough in the target reflection coherence spectrum curve; a determination module 1003 is used to determine an actual thickness value of the polishing layer according to a data set of a variation curve of a wavelength corresponding to a preset extreme point and the thickness of the polishing layer, and the target coherence extreme point, wherein the data set of a variation curve of a wavelength corresponding to a preset extreme point and the thickness of the polishing layer includes a variation curve of a wavelength corresponding to an extreme point with the thickness of the polishing layer under different coherence levels.

[0116] In some embodiments, the determination module 1003 is specifically used to determine the actual thickness value of the polishing layer according to the intersection of the wavelength corresponding to the target coherent extreme point, the wavelength corresponding to the preset extreme point and the polishing layer thickness variation curve data set.

[0117] In some embodiments, the target coherent extreme point includes a first coherent extreme point and a second coherent extreme point, and the determination module 1003 is specifically used to: determine the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the wavelength corresponding to the preset extreme point and the polishing layer thickness change curve data set; determine the actual thickness value of the polishing layer according to the number of intersection points and the polishing layer thickness values ​​corresponding to the intersection points.

[0118] In some embodiments, the data set of change curves of the wavelength corresponding to the preset extreme point and the polishing layer thickness includes a first change curve of the wavelength corresponding to the extreme point and the polishing layer thickness when the extreme point is a peak at different coherence levels, and a second change curve of the wavelength corresponding to the extreme point and the polishing layer thickness when the extreme point is a trough at different coherence levels; determining the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the data set of change curves of the wavelength corresponding to the preset extreme point and the polishing layer thickness, includes: obtaining the indication of the peak or trough in the target reflection coherent spectrum curve indicated by the first coherent extreme point and the second coherent extreme point; determining the number of intersection points according to the indication; wherein the first coherent extreme point indicates a peak or a trough, and the second coherent extreme point indicates a peak or a trough.

[0119] In some embodiments, the determination module 1003 is specifically used to: when the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve, determine the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point with the first change curve, and the intersection of the wavelength corresponding to the second coherent extreme point with the second change curve; when the number of intersection points between the wavelength corresponding to the first coherent extreme point and the first change curve is 1, or the number of intersection points between the wavelength corresponding to the second coherent extreme point and the second change curve is 1, determine that the polishing layer thickness value corresponding to the intersection point is the actual thickness value of the polishing layer.

[0120] In some embodiments, the determination module 1003 is also used to determine that the polishing layer thickness value corresponding to the intersection point of the wavelength corresponding to the first coherent extreme point and the first change curve is a first thickness value set, and the polishing layer thickness value corresponding to the intersection point of the wavelength corresponding to the second coherent extreme point and the second change curve is a second thickness value set when there is more than one intersection point between the wavelength corresponding to the first coherent extreme point and the first change curve, and when there is more than one intersection point between the wavelength corresponding to the second coherent extreme point and the second change curve; and when there is only one pair of target intersection points in the first thickness value set and the second thickness value set that satisfy equal thickness values, determine the polishing layer thickness value corresponding to the target intersection point as the actual thickness value of the polishing layer.

[0121] In some embodiments, there are m coherent extreme points between the first coherent extreme point and the second coherent extreme point, where m is an integer. The analysis module 1002 is further used to obtain the first coherent series set and the second coherent series set according to the coherent series corresponding to the multiple pairs of target intersection points when there are multiple pairs of target intersection points in the first thickness value set and the second thickness value set that satisfy equal thickness values; the determination module 1003 is further used to determine the polishing layer thickness value corresponding to the target intersection points in the first coherent series set and the second coherent series set that satisfy a preset coherent series relationship as the actual thickness value of the polishing layer, and the preset coherent series relationship is that the absolute value of the difference between the coherent series corresponding to the first coherent extreme point and the coherent series corresponding to the second coherent extreme point is equal to (m+1) / 2.

[0122] In some embodiments, the determination module 1003 is also used to: when the first coherent extreme point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a peak in the target reflection coherent spectrum curve, determine the number of intersection points according to the intersection of the first change curve with the wavelength corresponding to the first coherent extreme point, and the wavelength corresponding to the second coherent extreme point; when the first coherent extreme point indicates a trough in the target reflection coherent spectrum curve, and the second coherent extreme point indicates a trough in the target reflection coherent spectrum curve, determine the number of intersection points according to the intersection of the second change curve with the wavelength corresponding to the first coherent extreme point, and the wavelength corresponding to the second coherent extreme point.

[0123] In some embodiments, the acquisition module 1001 is also used to acquire multiple standard reflection coherence spectrum curves, each of the multiple standard reflection coherence spectrum curves corresponds to a different polishing layer thickness; the acquisition module 1001 is also used to acquire the extreme value of each standard reflection coherence spectrum curve, the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve; the analysis module 1002 is also used to obtain a data set of change curves of the wavelength corresponding to the preset extreme point and the polishing layer thickness based on the extreme value of each standard reflection coherence spectrum curve, the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve.

[0124] In some embodiments, the device further includes: an adjustment module. The acquisition module 1001 is further used to acquire the actual polishing rate of the wafer during the chemical mechanical polishing process; the determination module 1003 is further used to determine the target rate adjustment parameter according to the actual polishing rate and the preset standard polishing rate; the adjustment module is used to adjust the polishing rate of the wafer according to the target rate adjustment parameter so that the actual polishing rate matches the standard polishing rate.

[0125] In some embodiments, the target rate adjustment parameter includes a first adjustment parameter and a second adjustment parameter, the first adjustment parameter is obtained based on the ratio of a standard polishing rate to an actual polishing rate, and the second adjustment parameter is obtained based on the ratio of a difference between an actual polishing layer thickness value and a standard polishing layer thickness value to a preset multiple of the actual polishing rate; the adjustment module is specifically used to: adjust subsequent equipment parameters of the chemical mechanical polishing equipment based on the first adjustment parameter and current equipment parameters of the chemical mechanical polishing equipment, or based on the sum of the first adjustment parameter and the second adjustment parameter and the current equipment parameters of the chemical mechanical polishing equipment, so as to adjust the polishing rate of the wafer, the equipment parameters of the chemical mechanical polishing equipment include any one of the frequency of the polishing drive motor, the voltage of the polishing drive motor, and the input current of the pneumatic proportional solenoid valve.

[0126] The description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

[0127] It should be noted that in the embodiments of this application Fig.10The division of modules in the chemical mechanical polishing processing device shown is schematic, which is only a logical functional division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or it can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. It can also be implemented in the form of a combination of software and hardware.

[0128] It should be noted that in the embodiments of the present application, if the above method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can be essentially or partly reflected in the form of a software product, which is stored in a storage medium and includes several instructions for enabling an electronic device to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk. In this way, the embodiments of the present application are not limited to any specific combination of hardware and software.

[0129] The embodiment of the present application provides a computer device, which may be a server, and its internal structure diagram may be as follows: Fig.11 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above method is implemented.

[0130] An embodiment of the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the method provided in the above embodiment are implemented.

[0131] An embodiment of the present application provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the steps of the method provided in the above method embodiment.

[0132] Those skilled in the art will understand that Fig.11The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0133] In one embodiment, the chemical mechanical polishing processing device provided in the present application can be implemented in the form of a computer program. The computer program can be used in Fig.11 The computer device shown in the figure can be run. The memory of the computer device can store various program modules constituting the above-mentioned device. The computer program composed of various program modules enables the processor to execute the steps of the method of each embodiment of the present application described in this specification.

[0134] It should be noted here that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium, storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0135] It should be understood that "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in one embodiment" or "in some embodiments" appearing throughout the specification may not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments. The above description of each embodiment tends to emphasize the differences between the various embodiments, and the same or similar aspects can be referenced to each other. For the sake of brevity, this article will not repeat them.

[0136] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist at the same time, and object B exists alone.

[0137] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0138] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as: multiple modules or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or modules can be electrical, mechanical or other forms.

[0139] The modules described above as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules; they may be located in one place or distributed on multiple network units; some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0140] In addition, all functional modules in the embodiments of the present application may be integrated into one processing unit, or each module may be a separate unit, or two or more modules may be integrated into one unit; the above-mentioned integrated modules may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0141] A person skilled in the art can understand that: all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, read-only memories (ROM), magnetic disks or optical disks.

[0142] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling an electronic device to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0143] The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0144] The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0145] The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0146] The above is only an implementation method of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A chemical mechanical polishing method, characterized in that: include: During the chemical mechanical polishing process, a target reflection coherent spectrum curve of the polishing layer of the wafer is obtained; According to the target reflection coherent spectrum curve, a target coherent extreme value point and a wavelength corresponding to the target coherent extreme value point are obtained, wherein the target coherent extreme value point indicates a peak or a trough in the target reflection coherent spectrum curve; According to a data set of a variation curve of the wavelength corresponding to a preset extreme point and the polishing layer thickness, the actual thickness value of the polishing layer is determined, wherein the data set of a variation curve of the wavelength corresponding to the preset extreme point and the polishing layer thickness includes a variation curve of the wavelength corresponding to the extreme point with the polishing layer thickness under different coherence orders; wherein, when the wavelength corresponding to the extreme point is a peak, the corresponding coherence order is a positive integer; The data set of the variation curve of the wavelength corresponding to the preset extreme point and the polishing layer thickness is obtained by collecting a plurality of standard reflection coherence spectrum curves, and according to the extreme value of each standard reflection coherence spectrum curve in the plurality of standard reflection coherence spectrum curves, the wavelength corresponding to the extreme value of each standard reflection coherence spectrum curve and the coherence order, and each standard reflection coherence spectrum curve in the plurality of standard reflection coherence spectrum curves corresponds to a different polishing layer thickness; The step of determining the actual thickness value of the polishing layer according to the wavelength and polishing layer thickness variation curve data set corresponding to the preset extreme point and the target coherent extreme point comprises: Determine the actual thickness value of the polishing layer according to the intersection of the wavelength corresponding to the target coherent extreme point, the wavelength corresponding to the preset extreme point, and the change curve data set of the polishing layer thickness; The target coherent extreme point includes a first coherent extreme point and a second coherent extreme point, and the actual thickness value of the polishing layer is determined according to the intersection of the wavelength corresponding to the target coherent extreme point and the wavelength corresponding to the preset extreme point and the change curve data set of the polishing layer thickness, including: Determine the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the wavelength corresponding to the preset extreme point and the data set of the variation curve of the polishing layer thickness, wherein the number of intersection points is one or more; Determining the actual thickness value of the polishing layer according to the number of the intersection points and the thickness values ​​of the polishing layer corresponding to the intersection points; The determining the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the wavelength corresponding to the preset extreme point and the data set of the variation curve of the polishing layer thickness comprises: Obtaining indications of peaks or troughs in the target reflection coherent spectrum curve indicated by the first coherent extreme value point and the second coherent extreme value point; According to the indication situation, the number of the intersection points is determined; wherein the first coherent extreme value point indicates a peak or a trough, and the second coherent extreme value point indicates a peak or a trough.

2. The method according to claim 1, characterized in that The preset extreme point corresponding to the wavelength and polishing layer thickness change curve data set includes a first change curve of the wavelength and polishing layer thickness corresponding to the extreme point when the coherence order is different and the extreme point is a peak, and a second change curve of the wavelength and polishing layer thickness corresponding to the extreme point when the coherence order is different and the extreme point is a trough.

3. The method according to claim 2, characterized in that Determining the actual thickness value of the polishing layer according to the number of the intersection points and the thickness values ​​of the polishing layer corresponding to the intersection points includes: In a case where the first coherent extreme value point indicates a peak in the target reflection coherent spectrum curve, and the second coherent extreme value point indicates a trough in the target reflection coherent spectrum curve, the number of the intersection points is determined according to the intersection of the wavelength corresponding to the first coherent extreme value point and the first variation curve, and the intersection of the wavelength corresponding to the second coherent extreme value point and the second variation curve; When the number of intersection points between the wavelength corresponding to the first coherent extreme point and the first change curve is 1, or the number of intersection points between the wavelength corresponding to the second coherent extreme point and the second change curve is 1, the polishing layer thickness value corresponding to the intersection point is determined to be the actual thickness value of the polishing layer.

4. The method according to claim 3, characterized in that The method further comprises: In the case where the number of intersection points between the wavelength corresponding to the first coherent extreme point and the first change curve is multiple, and the number of intersection points between the wavelength corresponding to the second coherent extreme point and the second change curve is multiple, determining that the polishing layer thickness value corresponding to the intersection point between the wavelength corresponding to the first coherent extreme point and the first change curve is a first thickness value set, and the polishing layer thickness value corresponding to the intersection point between the wavelength corresponding to the second coherent extreme point and the second change curve is a second thickness value set; When there is only one pair of target intersection points satisfying equal thickness values ​​in the first thickness value set and the second thickness value set, the polishing layer thickness value corresponding to the target intersection point is determined as the actual thickness value of the polishing layer.

5. The method according to claim 4, characterized in that There are m coherent extreme value points between the first coherent extreme value point and the second coherent extreme value point, where m is an integer, and the method further includes: When there are multiple pairs of target intersection points satisfying equal thickness values ​​in the first thickness value set and the second thickness value set, a first coherence series set and a second coherence series set are obtained according to the coherence series corresponding to the multiple pairs of target intersection points respectively; The polishing layer thickness value corresponding to the target intersection point in the first coherent series set and the second coherent series set that satisfies a preset coherent series relationship is determined as the actual thickness value of the polishing layer, and the preset coherent series relationship is that the absolute value of the difference between the coherence series corresponding to the first coherent extreme point and the coherence series corresponding to the second coherent extreme point is equal to (m+1) / 2.

6. The method according to claim 1, characterized in that Before determining the actual thickness value of the polishing layer according to the wavelength and polishing layer thickness variation curve data set corresponding to the preset extreme point and the target coherent extreme point, the method further includes: Acquiring a plurality of standard reflection coherence spectrum curves, wherein each of the plurality of standard reflection coherence spectrum curves corresponds to a different polishing layer thickness; Obtaining the extreme value of each standard reflection coherence spectrum curve, and the wavelength and coherence order corresponding to the extreme value of each standard reflection coherence spectrum curve; According to the extreme value of each standard reflection coherent spectrum curve, the wavelength corresponding to the extreme value of each standard reflection coherent spectrum curve and the coherence order, a data set of variation curves of the wavelength corresponding to the preset extreme value point and the polishing layer thickness is obtained.

7. The method according to claim 1, characterized in that After determining the actual thickness value of the polishing layer according to the data set of the variation curve of the wavelength and the polishing layer thickness corresponding to the preset extreme point and the target coherent extreme point, the method further includes: During chemical mechanical polishing, the actual polishing rate of the wafer is obtained; Determining a target rate adjustment parameter according to the actual polishing rate and a preset standard polishing rate; The polishing rate of the wafer is adjusted according to the target rate adjustment parameter so that the actual polishing rate matches the standard polishing rate.

8. The method according to claim 7, characterized in that The target rate adjustment parameter includes a first adjustment parameter and a second adjustment parameter, wherein the first adjustment parameter is obtained according to the ratio of the standard polishing rate to the actual polishing rate, and the second adjustment parameter is obtained according to the ratio of the difference between the actual polishing layer thickness value and the standard polishing layer thickness value to the actual polishing rate of a preset multiple; The step of adjusting the polishing rate of the wafer according to the target rate adjustment parameter includes: According to the first adjustment parameter and the current equipment parameters of the chemical mechanical polishing equipment, or according to the sum of the first adjustment parameter and the second adjustment parameter and the current equipment parameters of the chemical mechanical polishing equipment, the subsequent equipment parameters of the chemical mechanical polishing equipment are adjusted to adjust the polishing rate of the wafer, and the equipment parameters of the chemical mechanical polishing equipment include any one of the frequency of the polishing drive motor, the voltage of the polishing drive motor, and the input current of the pneumatic proportional solenoid valve.

9. A chemical mechanical polishing processing device, characterized in that: include: An acquisition module, used for acquiring a target reflection coherent spectrum curve of a polishing layer of a wafer during a chemical mechanical polishing process; An analysis module, configured to obtain a target coherent extreme value point and a wavelength corresponding to the target coherent extreme value point according to the target reflection coherent spectrum curve, wherein the target coherent extreme value point indicates a peak or a trough in the target reflection coherent spectrum curve; A determination module, for determining the actual thickness value of the polishing layer according to a data set of a change curve of the wavelength corresponding to a preset extreme point and the polishing layer thickness, and the target coherent extreme point, wherein the data set of a change curve of the wavelength corresponding to the preset extreme point and the polishing layer thickness includes a change curve of the wavelength corresponding to the extreme point with the polishing layer thickness under different coherence orders; wherein, when the wavelength corresponding to the extreme point is a peak, the corresponding coherence order is a positive integer; The data set of the variation curve of the wavelength corresponding to the preset extreme point and the polishing layer thickness is obtained by collecting a plurality of standard reflection coherence spectrum curves, and according to the extreme value of each standard reflection coherence spectrum curve in the plurality of standard reflection coherence spectrum curves, the wavelength corresponding to the extreme value of each standard reflection coherence spectrum curve and the coherence order, and each standard reflection coherence spectrum curve in the plurality of standard reflection coherence spectrum curves corresponds to a different polishing layer thickness; The determination module is specifically used for: Determine the actual thickness value of the polishing layer according to the intersection of the wavelength corresponding to the target coherent extreme point, the wavelength corresponding to the preset extreme point, and the change curve data set of the polishing layer thickness; The target coherent extreme value point includes a first coherent extreme value point and a second coherent extreme value point, and the determination module is specifically used for: Determine the number of intersection points according to the intersection of the wavelength corresponding to the first coherent extreme point and / or the wavelength corresponding to the second coherent extreme point with the wavelength corresponding to the preset extreme point and the data set of the variation curve of the polishing layer thickness, wherein the number of intersection points is one or more; Determining the actual thickness value of the polishing layer according to the number of the intersection points and the thickness values ​​of the polishing layer corresponding to the intersection points; The determining module is further specifically used for: Obtaining indications of peaks or troughs in the target reflection coherent spectrum curve indicated by the first coherent extreme value point and the second coherent extreme value point; According to the indication situation, the number of the intersection points is determined; wherein the first coherent extreme value point indicates a peak or a trough, and the second coherent extreme value point indicates a peak or a trough.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 8 are implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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