Polishing method, polishing equipment, device and medium

Abstract

The invention provides a polishing method, polishing equipment, a polishing device and a medium, the polishing method comprises the steps that a polished silicon wafer sample is obtained based on preset polishing parameters, and the preset polishing parameters comprise a previous polishing parameter and / or a pre-stored first polishing parameter; the polishing parameters comprise at least one of polishing removal amount and polishing solution temperature; detecting the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameter; if the surface reflectivity is smaller than a first threshold value, at least one of the polishing removal amount and the temperature of the polishing solution is adjusted, and next-time polishing parameters are obtained; detecting the surface reflectivity of the silicon wafer sample obtained on the basis of the next polishing parameter; and the steps are executed circularly until it is detected that the surface reflectivity of the silicon wafer sample obtained based on the Nth polishing parameter is larger than or equal to a second threshold value, and the Nth polishing parameter is determined as the target polishing parameter. According to the polishing method, the polishing equipment, the device and the medium disclosed by the invention, bad cloud marks can be improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to a polishing method and polishing equipment, a device and a medium. Background Art

[0002] Wafer manufacturing is a key link in the development of the ultra-large-scale integrated circuit (IC) industry. As Moore's Law continues, the feature size of integrated circuits continues to shrink and approaches the theoretical limit, and the surface quality requirements of wafers are becoming more and more stringent. Therefore, the control of defect size and quantity in the wafer manufacturing process is becoming more and more stringent.

[0003] Chemical Mechanical Planarization (CMP) is a global surface planarization technology used to reduce the impact of wafer thickness variation and surface topography in the semiconductor manufacturing process. Since CMP can accurately and evenly planarize the wafer to the required thickness and flatness, it has become the most widely used surface planarization technology in the semiconductor manufacturing process.

[0004] The chemical mechanical polishing process uses a carrier head to press the wafer onto the surface of the polishing pad, relying on the relative movement between the wafer and the polishing pad and the abrasive particles in the polishing liquid to polish the wafer surface. However, during the polishing process, if the mechanical grinding and chemical grinding are not properly matched, a cloud mark defect will be produced on the wafer surface. Cloud mark defect is a stubborn defect in the wafer field. Summary of the invention

[0005] In order to solve at least one technical problem in the above-mentioned prior art, the embodiments of the present disclosure provide a polishing method and polishing equipment, device and medium.

[0006] The technical solutions provided by the embodiments of the present disclosure are as follows:

[0007] In a first aspect, an embodiment of the present disclosure provides a polishing method, comprising:

[0008] Obtaining a polished silicon wafer sample based on preset polishing parameters, wherein the preset polishing parameters include previous polishing parameters and / or pre-stored first polishing parameters, and the polishing parameters include at least one of a polishing removal amount and a polishing liquid temperature;

[0009] Detecting the surface reflectivity of the silicon wafer sample obtained based on the preset polishing parameters;

[0010] If the surface reflectivity is less than a first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain a subsequent polishing parameter;

[0011] Detecting the surface reflectivity of the silicon wafer sample obtained based on the last polishing parameters;

[0012] The above steps are executed in a loop until it is detected that the surface reflectivity of the silicon wafer sample obtained based on the Nth polishing parameter is greater than or equal to a second threshold, and the Nth polishing parameter is determined to be the target polishing parameter, wherein N is a positive integer greater than or equal to 1, and the second threshold is less than or equal to the first threshold.

[0013] Exemplarily, if the surface reflectivity is less than a first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain a subsequent polishing parameter specifically includes:

[0014] When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is less than a third threshold value, and the polishing removal amount in the previous polishing parameters is less than a target removal amount, the polishing removal amount is increased according to a predetermined first removal amount change gradient compared to the polishing removal amount in the previous polishing parameters to obtain a subsequent polishing parameter, wherein the second threshold value is less than or equal to the first threshold value, and the third threshold value is less than the second threshold value.

[0015] Exemplarily, if the surface reflectivity is less than a first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain a subsequent polishing parameter specifically includes:

[0016] When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is less than the third threshold value and the polishing removal amount in the previous polishing parameters reaches the target removal amount, the polishing liquid temperature is increased according to a predetermined temperature change gradient compared to the polishing liquid temperature in the previous polishing parameters to obtain the next polishing parameters.

[0017] Exemplarily, if the surface reflectivity is less than a first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain a subsequent polishing parameter specifically includes:

[0018] When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is greater than or equal to the third threshold and less than the second threshold, compared with the previous polishing parameters, the polishing liquid temperature is kept unchanged, and the polishing removal amount is reduced according to a predetermined second removal amount change gradient to obtain the next polishing parameters, wherein the third threshold is less than the second threshold.

[0019] Exemplarily, the third threshold is 90%, the first threshold is 99%, and the second threshold is 95%.

[0020] Exemplarily, in the method, adjusting at least one of the polishing removal amount and the polishing liquid temperature specifically includes:

[0021] When adjusting the polishing removal amount, the polishing removal amount is increased by increasing at least one of the polishing pressure and the polishing time.

[0022] In a second aspect, the present disclosure also provides a polishing device, including:

[0023] A polishing disc, wherein a plurality of reserved holes are provided on the disc surface of the polishing disc;

[0024] A detection device, arranged in the reserved hole, for detecting the surface reflectivity of the silicon wafer sample;

[0025] A control device is used to implement the polishing method as described above.

[0026] Exemplarily, the distances from at least three of the reserved holes to the center of the polishing disk are not equal.

[0027] In a third aspect, an embodiment of the present disclosure further provides a control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the polishing method as described above when executing the computer program.

[0028] In a third aspect, a computer-readable storage medium is also provided in an embodiment of the present disclosure, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the polishing method described above are implemented.

[0029] The beneficial effects brought by the embodiments of the present disclosure are as follows:

[0030] In the above scheme, by detecting the surface reflectivity of the silicon wafer sample after polishing, when the surface reflectivity is less than the first threshold, the polishing removal amount and / or the polishing liquid temperature are adjusted to adjust the polishing parameters at least once, and when the surface reflectivity of the silicon wafer sample obtained based on the adjusted Nth polishing parameters can reach the second threshold, the Nth polishing parameters are used as the target polishing parameters. In this way, through the polishing method of the embodiment of the present disclosure, the polishing parameters can be optimized by adjusting at least one of the polishing removal amount and the polishing liquid temperature to improve the poor cloud mark. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flow chart showing a polishing method in an embodiment of the present disclosure;

[0032] Figure 2 A schematic diagram showing the relative positions of the detection device and the silicon wafer;

[0033] Figure 3 A block diagram showing the structure of the control device. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0035] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0036] The features such as "parallel", "perpendicular", and "same" used in the embodiments of the present disclosure include the features such as "parallel", "perpendicular", and "same" in a strict sense, as well as the cases where "approximately parallel", "approximately perpendicular", "approximately the same", etc. include certain tolerances, taking into account the tolerances associated with the measurement of specific quantities (e.g., the limitations of the measurement system), and represent the acceptable deviation range for a specific value determined by ordinary technicians in the field. For example, "approximately" can mean within one or more standard deviations, or within 3% or 5% of the value.

[0037] In addition, in this document, unless otherwise defined, the terms "substantially", "substantially", "approximately" and "about" are used to describe and explain small changes. When used with an event or situation, these terms can cover situations where the event or situation occurs exactly, and can also cover situations where the event or situation occurs approximately. For example, when used with a numerical value, these terms can include a range of variation of less than or equal to 10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, less than or equal to ±0.05%. The term "substantially coplanar" can refer to two surfaces being arranged along the same plane in the micrometer range, for example, arranged along the same plane within 40μm, 30μm, 20μm, 10μm or 1μm.

[0038] In this application, chemical mechanical polishing is also referred to as chemical mechanical planarization, and a silicon wafer is also referred to as a chip, a wafer, a substrate or a substrate, etc., and their meanings and actual functions are equivalent.

[0039] like Figure 1 As shown, the present disclosure provides a polishing method, comprising the following steps:

[0040] Step S01, obtaining a polished silicon wafer sample based on preset polishing parameters;

[0041] The preset polishing parameters include the previous polishing parameters and / or the pre-stored first polishing parameters, and the polishing parameters include at least one of the polishing removal amount and the polishing liquid temperature.

[0042] Step S02, detecting the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters;

[0043] Step S03, if the surface reflectivity is less than a first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain a subsequent polishing parameter;

[0044] Step S04, detecting the surface reflectivity of the silicon wafer sample obtained based on the last polishing parameter;

[0045] Step S05, looping through the above steps S01 to S04 until it is detected that the surface reflectivity of the silicon wafer sample obtained based on the Nth polishing parameter is greater than or equal to a second threshold, determining the Nth polishing parameter as the target polishing parameter, wherein N is a positive integer greater than or equal to 1, and the second threshold is less than or equal to the first threshold.

[0046] In the above scheme, first, the surface reflectivity of the silicon wafer sample after polishing based on the preset polishing parameters can be detected. When the surface reflectivity is greater than or equal to the first threshold, it can be considered that the current silicon wafer sample must meet the requirements, for example, there is no cloud mark, and there is no need to adjust the polishing parameters at this time; when it is detected that the surface reflectivity is less than the first threshold, the next adjustment step can be performed. Specifically, the polishing parameters are adjusted at least once by adjusting the polishing removal amount and / or the polishing liquid temperature to obtain the next polishing parameters, and the surface reflectivity of the silicon wafer sample after polishing based on the next polishing parameters is detected. When it is detected that the surface reflectivity does not reach the second threshold, the above parameter adjustment steps can be repeated until the Nth polishing parameters are obtained after one or more adjustments. When the surface reflectivity of the obtained silicon wafer sample is greater than or equal to the second threshold, the Nth polishing parameters are used as the target polishing parameters.

[0047] In this way, through the polishing method of the embodiment of the present disclosure, the polishing parameters can be optimized by adjusting at least one of the polishing removal amount and the polishing liquid temperature to improve the cloud mark defect.

[0048] It should be noted that in the above scheme, the silicon wafer sample is polished once and the surface reflectivity of the silicon wafer sample is detected once after polishing as an adjustment step. In the entire cycle from the first to the Nth polishing, except for the first adjustment step in which the silicon wafer sample is polished based on the pre-set polishing parameters, the subsequent adjustment steps can be performed after the polishing parameters of the previous adjustment step are modulated. Here, the polishing parameters pre-set in the first polishing detection step can be set based on experience or industry practices.

[0049] In addition, it should be noted that the target polishing parameters refer to the polishing parameters when a specific index or condition is desired to be achieved during the polishing process of the silicon wafer. In other words, the target polishing parameters are the polishing parameters used in the subsequent polishing process of the silicon wafer.

[0050] It should also be noted that in actual applications, different grades or batches of silicon wafer products have different production requirements. For example, some silicon wafer products require their reflectivity to reach 99% to meet the polishing requirements. In some exemplary embodiments, the first threshold may be 99%.

[0051] Generally speaking, in practical applications, when the reflectivity of a silicon wafer product reaches 95% or more, it is considered to meet the requirements of the general product polishing process. When the surface reflectivity of the silicon wafer sample obtained by the Nth polishing parameter can reach 95% to 99%, it is considered that the surface reflectivity of the silicon wafer after polishing can meet the production requirements. That is, the second threshold value can be 95% to 99%. For example, the second threshold value can be 95%, 96%, 97%, 98% or 99%. The specific value of the second threshold value can be selected according to the product specification requirements.

[0052] In addition, it should be noted that the surface reflectivity of the silicon wafer sample obtained based on the preset polishing parameters, when lower than 99%, can also include the following two situations: one is that the surface reflectivity of the silicon wafer is less than 95%, and the other is that the surface reflectivity of the silicon wafer is greater than or equal to 95% and less than 99%.

[0053] Generally speaking, when the surface reflectivity of the silicon wafer after polishing reaches 95% or more, it can be considered to meet the production requirements. Therefore, in some embodiments, regardless of the above situation, the polishing parameters can be further adjusted until it is detected that the surface reflectivity of the silicon wafer sample obtained based on the Nth polishing parameters is greater than or equal to 95%. Among them, in the case where the surface reflectivity of the silicon wafer sample obtained based on the preset polishing parameters is lower than 95%, the Nth polishing parameters are used as the target polishing parameters to perform subsequent polishing of the silicon wafers, so that the silicon wafers after subsequent polishing can meet the requirement that the surface reflectivity is greater than or equal to 95%; and in the case where the surface reflectivity of the silicon wafer sample obtained based on the preset polishing parameters is higher than 95% and less than 99%, although the silicon wafer sample obtained based on the preset polishing parameters has met the production requirements, in some practical applications, the surface reflectivity of the silicon wafer sample only needs to reach 95%, indicating that when polishing the silicon wafer based on the preset polishing parameters, there are some unnecessary factors affecting the production efficiency, such as polishing time, polishing liquid temperature or removal amount, etc. Therefore, the polishing parameters can also be adjusted to the next step at this time, until the Nth polishing parameters are used as the target polishing parameters for subsequent polishing of the silicon wafers, so that the polishing parameters can be adjusted to more reasonable target polishing parameters while satisfying the requirement that the surface reflectivity of the silicon wafers after subsequent polishing can meet the requirement that the surface reflectivity is greater than or equal to 95%, so as to improve the production efficiency.

[0054] It should be noted that, in the above scheme, the silicon wafer sample can be replaced every time the polishing parameters are adjusted.

[0055] It should also be noted that the polishing equipment may include a polishing plate, for example, taking a double-sided polishing equipment as an example, the polishing equipment may include an upper polishing plate and a lower polishing plate arranged relatively to each other. The polishing equipment may also include a polishing liquid temperature feedback component and a removal amount feedback component, a control device, etc. The polishing liquid feedback component may feed back the polishing liquid temperature to the control device, and the removal amount feedback component may feed back the polishing removal amount to the control device. The control device may control the entire polishing equipment to complete the polishing process based on the set polishing parameters.

[0056] The surface reflectivity of the silicon wafer sample can be achieved by a detection device. Specifically, in a polishing device, a plurality of reserved holes may be distributed on the surface of the polishing disk, and the detection device may be installed in the reserved holes to detect the reflectivity of the polished silicon wafer surface.

[0057] For example, taking a double-sided polishing device as an example, a plurality of reserved holes are provided on the surface of the upper polishing plate, and the detection device is installed in the reserved holes. For example, the detection device can be implemented by any suitable sensing device such as an optical sensor.

[0058] For example, the wavelength of the detection light of the optical sensor can be visible light of 400nm to 700nm. Based on the optical sensor, the detection error of the silicon wafer surface reflectivity can be less than 0.1%, and the detection accuracy is high. However, it is not limited to this.

[0059] For example, Table 1 shows the relationship between the polishing removal amount and the surface reflectivity after the silicon wafer sample was polished under three different polishing parameters. Among them, only the polishing removal amount under the three different polishing parameters is a single variable.

[0060] Table 1

[0061] Removal thickness (μm) Surface reflectivity (detection light wavelength is 45nm) Test Example 1 Greater than 0.6 99％ Test Example 2 0.3～0.6 95％ Test Example 3 Less than 0.3 90％

[0062] It can be seen that the polishing removal amount of the silicon wafer is linearly related to the surface reflectivity of the silicon wafer within a certain range (such as the target removal amount). The greater the polishing removal amount, the greater the surface reflectivity of the silicon wafer.

[0063] Based on this, in some exemplary embodiments, the above step S03 specifically includes:

[0064] Step S031. When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is less than a third threshold value, and the polishing removal amount in the previous polishing parameters is less than a target removal amount, compared with the polishing removal amount in the previous polishing parameters, the polishing removal amount is increased according to a predetermined first removal amount change gradient to obtain a subsequent polishing parameter, wherein the second threshold value is less than or equal to the first threshold value, and the third threshold value is less than the second threshold value.

[0065] By adopting the above scheme, when the surface reflectivity of the silicon wafer sample is too low, lower than the third threshold value (for example, lower than 90%), since the polishing removal amount of the silicon wafer is linearly related to the surface reflectivity of the silicon wafer within a certain range (for example, the target removal amount), when the polishing removal amount of the silicon wafer sample does not reach the target removal amount, the polishing removal amount can be gradually increased according to the first removal amount change gradient to adjust the polishing parameters. Each time a removal amount gradient is increased, the surface reflectivity of the silicon wafer sample obtained by the adjusted polishing parameters is detected once until the surface reflectivity of the silicon wafer sample reaches the second threshold value, so as to improve the surface reflectivity of the silicon wafer and reduce the cloud mark defect phenomenon. Wherein, the first removal amount change gradient can be, for example, that the removal amount increases by 0.1 microns each time the polishing parameters are adjusted.

[0066] However, after the polishing removal amount of the silicon wafer reaches the target removal amount, further increasing the polishing removal amount may instead reduce the surface reflectivity of the silicon wafer. Therefore, if the polishing removal amount of the silicon wafer has been adjusted to the target removal amount and the surface reflectivity of the silicon wafer has not reached the second threshold, the polishing parameters can be adjusted by adjusting the polishing liquid temperature.

[0067] Specifically, the above step S03 further includes:

[0068] Step S032: When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is less than the third threshold value and the polishing removal amount in the previous polishing parameters reaches the target removal amount, the polishing liquid temperature is increased according to a predetermined temperature change gradient compared to the polishing liquid temperature in the previous polishing parameters to obtain the next polishing parameters.

[0069] According to the above scheme, when the polishing removal amount is increased to the target polishing amount, if the surface reflectivity of the silicon wafer still does not reach the second threshold, the polishing liquid temperature can be gradually increased according to the predetermined temperature change gradient to adjust the polishing parameters. Each time a temperature gradient is increased, the surface reflectivity of the silicon wafer sample obtained by the adjusted polishing parameters is detected until the surface reflectivity of the silicon wafer sample reaches the second threshold. For example, the temperature of the previous polishing liquid is 23°, and the temperature of the next polishing liquid is increased by 1° compared to the temperature of the previous polishing liquid. However, this is not limited to this.

[0070] In addition, it should be noted that in the above-mentioned step S032, when the polishing liquid temperature is increased according to a predetermined temperature change gradient compared to the polishing liquid temperature in the previous polishing parameters, the polishing liquid temperature adjustment can be based on the initial polishing removal amount. That is, when adjusting the polishing liquid temperature, the polishing removal amount is first reset to the polishing removal amount in the initial polishing parameters, and only the polishing liquid temperature is used as a single variable to adjust the polishing parameters.

[0071] Furthermore, if the surface reflectivity of the silicon wafer sample has not reached the second threshold value when the polishing liquid temperature is adjusted to the temperature threshold, the polishing removal amount can be adjusted again in succession according to the predetermined third removal amount change gradient while keeping the current polishing liquid temperature unchanged to obtain the adjusted polishing parameters until the surface reflectivity of the silicon wafer sample reaches the second threshold value.

[0072] It should be noted that due to the different requirements for the optimal polishing liquid temperature threshold before and after changing the polishing parameters of different devices or the same device, the influence of the polishing liquid temperature on the surface reflectivity is uncertain. When the gradient of each adjustment of the polishing liquid temperature is smaller, it is more conducive to determining the optimal polishing parameters.

[0073] In addition, when the surface reflectivity of the silicon wafer sample is lower than the first threshold (for example, 99%) but higher than the third threshold (for example, lower than 90%), the above step S03 specifically includes:

[0074] Step S033: When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is greater than or equal to the third threshold and less than the second threshold, compared with the previous polishing parameters, the polishing liquid temperature is kept unchanged, and the polishing removal amount is reduced according to a predetermined second removal amount change gradient to obtain the next polishing parameters, wherein the third threshold is less than the second threshold.

[0075] The second removal amount change gradient is smaller than the first removal amount change gradient. In other words, the polishing removal amount can be slightly reduced in the above step S033 until the surface reflectivity of the silicon wafer reaches a second threshold value (eg, 95%).

[0076] In addition, in some exemplary embodiments, in the method, adjusting at least one of the polishing removal amount and the polishing liquid temperature specifically includes: when adjusting the polishing removal amount, increasing the polishing removal amount by increasing at least one of the polishing pressure and the polishing time.

[0077] By adopting the above scheme, increasing either the polishing pressure or the polishing time will increase the polishing removal amount. Therefore, the polishing removal amount can be increased by increasing either the polishing pressure or the polishing time.

[0078] Moreover, since the larger the polishing removal amount is within a certain range, the higher the surface reflectivity of the silicon wafer is, but if it exceeds a limit value (target removal amount), the polishing removal amount will continue to increase, which will lead to a decrease in the surface reflectivity of the silicon wafer. Therefore, the polishing removal amount can be limited by setting the polishing pressure or polishing time to control the polishing removal amount within the target removal amount, thereby making the surface reflectivity controllable and ensuring that the polishing removal amount is linear with the surface reflectivity within a range less than or equal to the target removal amount.

[0079] In addition, it should be noted that the entire polishing process of the silicon wafer may include multiple polishing steps such as fine polishing and fine polishing. In the polishing method provided in the embodiment of the present disclosure, the adjustment of the polishing parameters may be the adjustment of the polishing parameters for the last fine polishing step. However, it is not limited to this.

[0080] In addition, the present disclosure also provides a polishing device, including:

[0081] A polishing disc, wherein a plurality of reserved holes are provided on the disc surface of the polishing disc;

[0082] A detection device, arranged in the reserved hole, for detecting the surface reflectivity of the silicon wafer sample;

[0083] A control device is used to implement the polishing method described in the embodiment of the present disclosure.

[0084] Exemplarily, the distances from at least three of the reserved holes to the center of the polishing plate are not equal. Figure 2 As shown, each of the three reserved holes is equipped with a detection device 20. In this way, the silicon wafer 10 can be rotated by rotating the polishing plate. During the rotation of the silicon wafer 10, the detection devices 20 located at different radial positions of the silicon wafer 10 can scan the silicon wafer 10, thereby realizing the reflectivity detection of different radial areas on the surface of the silicon wafer 10.

[0085] Exemplarily, the control device may be a PID controller (proportional-integral-differential controller). A PID controller is a feedback controller widely used in automatic control systems. It achieves precise control of system output by real-time calculation and adjustment of control errors. The main function of a PID controller is to adjust the control variable according to the error between the set target value (set point) and the actual measured value so that the system output is as close to the set value as possible.

[0086] See also Figure 3 As shown, the control device may include:

[0087] An acquisition module 31 is used to receive the surface reflectivity fed back by the detection device;

[0088] A temperature adjustment module 32, configured to obtain an adjusted polishing liquid temperature according to a predetermined temperature change gradient based on the surface reflectivity;

[0089] A removal amount adjustment module 33, used to obtain an adjusted polishing removal amount according to a predetermined removal amount change gradient based on the surface reflectivity;

[0090] The polishing control module 34, the temperature adjustment module and the removal amount adjustment module are both connected to the detection device and the polishing control module, and the temperature adjustment module and the removal amount adjustment module are arranged in parallel, and the polishing control module is used to control the polishing disk to polish the silicon wafer sample based on the adjusted polishing liquid temperature and / or the adjusted polishing removal amount.

[0091] Obviously, the polishing equipment provided in the embodiment of the present disclosure also has the beneficial effects brought by the polishing method provided in the embodiment of the present disclosure, which will not be elaborated here.

[0092] In addition, an embodiment of the present disclosure also provides a control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the polishing method described above when executing the computer program.

[0093] In addition, a computer-readable storage medium is provided in an embodiment of the present disclosure. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the steps of the polishing method described above are implemented.

[0094] The above-mentioned computer-readable storage medium, because the computer program stored in its memory is executed by the processor to implement the steps in the above-mentioned method embodiments, similarly, the calibration of the wafer position can be automatically completed without opening the equipment chamber for operation, thereby avoiding contamination of the chamber or wafer.

[0095] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0096] There are a few points to note:

[0097] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0098] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0099] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0100] The above are only specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and the protection scope of the present disclosure shall be based on the protection scope of the claims.

Claims

1. A polishing method, characterized in that: include: Obtaining a polished silicon wafer sample based on preset polishing parameters, wherein the preset polishing parameters include previous polishing parameters and / or pre-stored first polishing parameters, and the polishing parameters include at least one of a polishing removal amount and a polishing liquid temperature; Detecting the surface reflectivity of the silicon wafer sample obtained based on the preset polishing parameters; If the surface reflectivity is less than a first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain a subsequent polishing parameter; Detecting the surface reflectivity of the silicon wafer sample obtained based on the last polishing parameters; The above steps are executed in a loop until it is detected that the surface reflectivity of the silicon wafer sample obtained based on the Nth polishing parameter is greater than or equal to a second threshold, and the Nth polishing parameter is determined to be the target polishing parameter, wherein N is a positive integer greater than or equal to 1, and the second threshold is less than or equal to the first threshold.

2. The polishing method according to claim 1, characterized in that: If the surface reflectivity is less than the first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain the next polishing parameter specifically includes: When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is less than a third threshold value, and the polishing removal amount in the previous polishing parameters is less than a target removal amount, the polishing removal amount is increased according to a predetermined first removal amount change gradient compared to the polishing removal amount in the previous polishing parameters to obtain a subsequent polishing parameter, wherein the second threshold value is less than or equal to the first threshold value, and the third threshold value is less than the second threshold value.

3. The polishing method according to claim 2, characterized in that: If the surface reflectivity is less than the first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain the next polishing parameter specifically includes: When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is less than the third threshold value and the polishing removal amount in the previous polishing parameters reaches the target removal amount, the polishing liquid temperature is increased according to a predetermined temperature change gradient compared to the polishing liquid temperature in the previous polishing parameters to obtain the next polishing parameters.

4. The polishing method according to claim 1, characterized in that: If the surface reflectivity is less than the first threshold, adjusting at least one of the polishing removal amount and the polishing liquid temperature to obtain the next polishing parameter specifically includes: When the surface reflectivity of the silicon wafer sample obtained based on the previous polishing parameters is greater than or equal to the third threshold and less than the second threshold, compared with the previous polishing parameters, the polishing liquid temperature is kept unchanged, and the polishing removal amount is reduced according to a predetermined second removal amount change gradient to obtain the next polishing parameters, wherein the third threshold is less than the second threshold.

5. The polishing method according to any one of claims 2 to 4, characterized in that: The first threshold is 99%, the second threshold is 95%, and the third threshold is 90%.

6. The polishing method according to claim 1, characterized in that: In the method, adjusting at least one of the polishing removal amount and the polishing liquid temperature specifically includes: When adjusting the polishing removal amount, the polishing removal amount is increased by increasing at least one of the polishing pressure and the polishing time.

7. A polishing device, characterized in that: include: A polishing disc, wherein a plurality of reserved holes are provided on the disc surface of the polishing disc; A detection device, arranged in the reserved hole, for detecting the surface reflectivity of the silicon wafer sample; A control device for implementing the polishing method according to any one of claims 1 to 6.

8. The polishing device according to claim 7, characterized in that: The distances from at least three of the reserved holes to the center of the polishing disk are unequal.

9. A control device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the polishing method according to any one of claims 1 to 6 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the polishing method according to any one of claims 1 to 6 are implemented.

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