Silicon wafer processing methods and apparatus

Abstract

This invention discloses a silicon wafer processing method and apparatus. In one aspect, a silicon wafer processing method is provided for use in double-sided polishing of silicon wafers. The method includes, during the double-sided polishing process, real-time monitoring of the pressure applied to the silicon wafer and the rotational speed of the polishing pad polishing the silicon wafer; classifying the pressure into one of a preset plurality of pressure ranges and the rotational speed into one of a preset plurality of speed ranges; and providing a polishing fluid with a corresponding formulation in the double-sided polishing process according to the classified pressure range and the classified speed range.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor processing technology, specifically, it relates to a silicon wafer processing method and apparatus. Prior Technology

[0002] Double-sided polishing of silicon wafers is a crucial step in semiconductor manufacturing. Its purpose is to remove minute impurities and roughness from the silicon wafer surface through physical and chemical processes, resulting in a highly flat, smooth, and clean surface that provides a solid foundation for subsequent microelectronic component manufacturing. This technology typically employs double-sided polishing equipment. The relative movement between the polishing pad and the silicon wafer, combined with the action of the polishing slurry, achieves precise surface finishing of the silicon wafer. The polishing slurry plays a key role in this process; it not only provides abrasive for physical grinding but also removes surface oxide layers and other impurities through chemical reactions. Furthermore, it influences the temperature, pressure, and other conditions during the polishing process, thereby affecting the polishing outcome.

[0003] In related silicon wafer double-sided polishing technologies, to ensure polishing quality, polishing operations are typically performed within a certain operating speed and pressure range, and an appropriate polishing fluid formula is selected. For example, when the operating speed and pressure are within a preset suitable range, a specific polishing fluid formula is chosen, in which parameters such as abrasive fineness, chemical composition, and pH value are optimized to achieve effective polishing of the silicon wafer surface under these operating conditions, ensuring that the flatness and particle level of the silicon wafer meet certain standards.

[0004] However, in actual production processes, even when operating speed and pressure are within normal ranges, fluctuations and changes are unavoidable. These fluctuations can alter the interaction between the polishing slurry and the silicon wafer, adversely affecting the polishing effect. Specifically, when the operating speed or pressure is too high or too low, the abrasive distribution, chemical composition, and pH value of the polishing slurry may not be effectively controlled, making it unable to adapt to changed polishing conditions. In such cases, even if the polishing slurry formulation remains unchanged, key indicators such as the flatness and particle level of the silicon wafer will deteriorate. For example, excessive pressure may cause scratches or dents on the silicon wafer surface, while insufficient pressure may reduce polishing efficiency, failing to effectively remove surface impurities and thus affecting the overall quality of the silicon wafer. Furthermore, changes in speed also affect the flow and distribution of the polishing slurry, further exacerbating the instability of the silicon wafer surface quality. Therefore, the processing methods in related technologies are limited in their ability to maintain consistently good polishing results when faced with fluctuating operating conditions. Summary of the Invention

[0005] This section provides a general overview of the invention, rather than a full disclosure of the entire scope or all features of the invention.

[0006] The purpose of this invention is to provide a method and apparatus that can maintain a high level of polishing quality of silicon wafers even when pressure and rotation speed fluctuate and change.

[0007] To achieve the above objectives, according to a first aspect of the present invention, a silicon wafer processing method is provided for use in the double-sided polishing of silicon wafers, comprising: During the double-sided polishing process, the pressure applied to the silicon wafer and the rotational speed of the polishing pad used to polish the silicon wafer are monitored in real time. The pressure is categorized into one of several preset pressure ranges, and the rotational speed is categorized into one of several preset speed ranges; Polishing fluids with corresponding formulations are provided for double-sided polishing, based on the pressure range and speed range to which they are classified.

[0008] In some implementations, multiple pressure ranges are defined by a total pressure range of 800 daN to 1700 daN, and multiple speed ranges are defined by a total speed range of 20 rpm to 40 rpm.

[0009] In some embodiments, the pressure ranges divided by the total pressure range are: 800 daN to 1000 daN, 1000 daN to 1400 daN, and 1400 daN to 1700 daN, and the speed ranges divided by the total speed range are: 20 rpm to 25 rpm, 25 rpm to 35 rpm, and 35 rpm to 40 rpm.

[0010] In some embodiments, the polishing fluid consists of abrasives, oxidants, dispersants, surfactants, complexing agents, and water.

[0011] In some embodiments, the polishing slurry formulation includes: the particle size of the abrasive, the mass percentage of the abrasive, the mass percentage of the oxidant, the mass percentage of the dispersant, the mass percentage of the surfactant, the mass percentage of the complexing agent, and the pH value of the polishing slurry.

[0012] In some embodiments, the abrasive is SiO2 (silicon dioxide), the oxidant is H2O2 (hydrogen peroxide), the dispersant is sodium polyacrylate, the surfactant is fatty alcohol polyoxyethylene ether, and the complexing agent is ethylenediaminetetraacetic acid.

[0013] In some embodiments, the polishing fluids formulated accordingly for double-sided polishing, based on the pressure range and speed range classified, include: The required content of each component in the polishing slurry is determined based on the pressure range and speed range to which it is classified, and the polishing slurry is prepared according to the content.

[0014] In some embodiments, the polishing fluids formulated accordingly for double-sided polishing, based on the pressure range and speed range classified, include: Polishing fluid is provided during double-sided polishing when the pressure is within the pressure range and the rotation speed is within the pressure range for a duration greater than or equal to a predetermined duration.

[0015] According to another aspect of the present invention, a silicon wafer processing apparatus is also provided for use in double-sided polishing of silicon wafers, comprising: The monitoring unit is used to monitor in real time the pressure applied to the silicon wafer and the rotational speed of the polishing pad used to polish the silicon wafer during the double-sided polishing process; The classification unit is used to classify the pressure into one of a set of preset pressure ranges and to classify the rotation speed into one of a set of preset speed ranges. The supply unit is used to provide polishing fluid with the appropriate formulation in double-sided polishing according to the pressure range and the speed range.

[0016] In some embodiments, the silicon wafer processing apparatus further includes: The determining unit is used to determine the required content of each component in the polishing fluid based on the pressure range and the speed range to which they are classified. The configuration unit is used to configure the polishing liquid according to the content.

[0017] According to the above implementation method, by real-time monitoring of pressure and rotation speed, and dynamically adjusting the formula of polishing fluid based on the monitoring results, it can be ensured that the characteristics of polishing fluid always match the current operating conditions throughout the polishing process. This allows the silicon wafers to maintain a relatively good level of properties such as flatness and particle size even when pressure and rotation speed fluctuate and change, significantly improving the stability of polishing quality. Simple Explanation of the Diagram

[0018] The features and advantages of embodiments of the present invention will become more readily understood from the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show details of specific parts. Figure 1 is a schematic diagram of double-sided polishing of silicon wafers. Figure 2 is a flowchart of a silicon wafer processing method according to an embodiment of the present invention. Figure 3 is a schematic diagram of the components of a silicon wafer processing apparatus according to an embodiment of the present invention. In the accompanying drawings, the same or corresponding technical features, parts or components are represented by the same or corresponding reference numerals. Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and exemplary embodiments. It should be noted that the following detailed description of the invention is for illustrative purposes only and is not intended to limit the scope of the invention.

[0020] It should be noted that, for clarity, not all features of a particular embodiment are described or shown in the specification and drawings. Furthermore, to avoid unnecessary details obscuring the technical solutions of interest in this invention, only the device structures and parts closely related to the technical solutions of this invention are described and shown in the specification and drawings, while other details that are not closely related to the technical content of this invention and are known to those skilled in the art are omitted.

[0021] In the semiconductor manufacturing industry, double-sided polishing technology for silicon wafers is crucial for ensuring high-quality silicon wafer surfaces. This technology utilizes physical and chemical processes, leveraging the relative motion between the polishing pad and the silicon wafer, along with the synergistic effect of the polishing slurry, to remove minute unevenness and impurities from the silicon wafer surface, achieving a highly flat, smooth, and clean surface. However, this technology faces numerous challenges in practical applications. While selecting a suitable polishing slurry formulation within a preset operating speed and pressure range is common practice, fluctuations in operating conditions during actual production, such as instability in speed and pressure, often lead to a decline in polishing effectiveness. These fluctuations cause the characteristics of the polishing slurry, such as abrasive distribution, chemical composition, and pH value, to become unsuitable for the changed polishing conditions, thus affecting the flatness and particle size distribution of the silicon wafer and reducing the overall quality of the product.

[0022] To address this limitation of related technologies, this invention proposes an innovative silicon wafer processing method, which will be described in detail below.

[0023] Referring to Figures 1 and 2, this embodiment of the invention provides a silicon wafer processing method for use in the double-sided polishing of silicon wafer W. The method may include the following steps S101, S102 and S103.

[0024] Step S101: During the double-sided polishing process, the pressure applied to the silicon wafer W and the rotational speed of the polishing pad 2 polishing the silicon wafer W are monitored in real time. As shown in Figure 1, the pressure applied to the silicon wafer W is schematically indicated by multiple arrows on the upper and lower sides of the silicon wafer W, and the rotation of the polishing pad 2 polishing the silicon wafer W is schematically indicated by the axis X and the elliptical arrows around the axis X. In addition, the "rotational speed of the polishing pad 2" here refers to the speed in a reference frame that is stationary relative to the silicon wafer W, or the relative speed between the polishing pad 2 and the silicon wafer W. Furthermore, the rotation of the polishing pad 2 around the axis X in Figure 1 is merely exemplary, and the present invention is not limited thereto. For example, the polishing pad 2 can also rotate around other axes.

[0025] Step S102: Classify the pressure into one of a preset multiple pressure ranges, and classify the rotation speed into one of a preset multiple speed ranges.

[0026] Step S103: According to the pressure range and speed range, a polishing slurry S with the corresponding formulation is provided in double-sided polishing, as schematically shown by hollow arrows in Figure 1. Additionally, Figure 1 exemplarily shows that the polishing slurry S is provided to the polishing pad 2 above the silicon wafer W through a pipe. In this case, the micropores of the polishing pad 2 can adsorb and store a certain amount of polishing slurry S. When the silicon wafer W and the polishing pad 2 are in close contact and begin relative movement, the polishing slurry S in the polishing pad 2 will gradually be released from the micropores under the action of pressure and friction, filling the gap between the polishing pad 2 and the silicon wafer W.

[0027] This invention, by real-time monitoring of pressure and rotation speed and dynamically adjusting the formula of polishing slurry S based on the monitoring results, ensures that the characteristics of polishing slurry S (such as abrasive fineness, chemical composition, pH value, etc.) always match the current operating conditions throughout the polishing process. This allows the silicon wafer W to maintain a relatively good level in terms of flatness and particle size even when pressure and rotation speed fluctuate and change, significantly improving the stability of polishing quality.

[0028] For example, when the pressure or rotational speed is too high, traditional polishing slurry formulations may cause scratches or dents on the surface of the silicon wafer W. This invention effectively reduces the occurrence of these surface defects by adjusting the polishing slurry S formulation in a timely manner when pressure and rotational speed fluctuate. For instance, when the pressure is detected to be excessively high, the polishing slurry S may be adjusted to increase the fine distribution range of the abrasive particles and the buffering capacity of the chemical components, thereby maintaining good polishing performance under high pressure and preventing scratches or dents on the surface of the silicon wafer W.

[0029] For example, at low pressures or rotational speeds, traditional polishing slurry formulations may lead to reduced polishing efficiency, failing to effectively remove impurities from the surface of the silicon wafer W. This invention, by dynamically adjusting the formulation of the polishing slurry S, optimizes the chemical reaction and physical abrasive effects of the slurry at low pressures or low rotational speeds, thereby improving polishing efficiency. For instance, when the rotational speed is detected to be too low, the formulation of the polishing slurry S may be adjusted to increase the content of oxidants and surfactants, thus maintaining a high polishing efficiency even at low speeds and ensuring that impurities on the surface of the silicon wafer W are effectively removed.

[0030] In some embodiments of the present invention, multiple pressure ranges are defined by a total pressure range of 800 daN to 1700 daN, and multiple speed ranges are defined by a total speed range of 20 rpm to 40 rpm.

[0031] With a total pressure range of 800 daN to 1700 daN and a total speed range of 20 rpm to 40 rpm, this method covers common operating conditions in double-sided polishing technology. This means that in a typical double-sided polishing process, regardless of changes in pressure and speed, a corresponding polishing fluid S formulation can be found within these ranges. This broad applicability ensures that this method can operate stably in a variety of different production environments and adapt to the processing needs of different batches of silicon wafers W.

[0032] In some embodiments of the present invention, the ranges divided by the total pressure range can be: 800 daN to 1000 daN, 1000 daN to 1400 daN, and 1400 daN to 1700 daN, and the ranges divided by the total speed range can be: 20 rpm to 25 rpm, 25 rpm to 35 rpm, and 35 rpm to 40 rpm.

[0033] This invention subdivides the total pressure range (800 daN to 1700 daN) into three sub-ranges: 800 daN to 1000 daN, 1000 daN to 1400 daN, and 1400 daN to 1700 daN. Similarly, the total speed range (20 rpm to 40 rpm) is subdivided into three sub-ranges: 20 rpm to 25 rpm, 25 rpm to 35 rpm, and 35 rpm to 40 rpm. This division not only avoids excessively frequent changes to the polishing slurry S formulation, reducing operational complexity and cost, but also ensures that the polishing quality of the silicon wafer W remains at a high level within each sub-range, preventing a decline in polishing quality due to excessively large ranges. Specifically, the polishing slurry formulation is relatively stable within each sub-range, making it easier to manage and adjust the supply of polishing slurry S, ensuring the continuity and stability of the production process. On the other hand, the polishing fluid formulations in each sub-range are carefully designed to effectively cope with pressure and speed variations within that range. For example, in the pressure range of 1000 daN to 1400 daN, the polishing fluid formulations can be optimized for aspects such as the fine distribution of abrasive particles and chemical composition to ensure good flatness and particle quality under moderate pressure.

[0034] In some embodiments of the present invention, the polishing fluid S may be composed of abrasive, oxidant, dispersant, surfactant, complexing agent and water.

[0035] During double-sided polishing, the abrasive acts as a physical grinding agent. Through contact and friction with the surface of the silicon wafer W, the abrasive removes minor surface imperfections, making the surface of the silicon wafer W smoother. Abrasives of different fineness can meet different polishing needs. For example, coarser abrasives are suitable for initially removing larger imperfections, while finer abrasives are used for fine polishing to improve surface smoothness. Oxidizing agents remove the oxide layer and other impurities on the surface of the silicon wafer W through chemical reactions during polishing. These chemical reactions soften the surface material, making it easier for the abrasive to remove, while also preventing surface re-oxidation, maintaining surface cleanliness and activity. Dispersants ensure that the abrasive is evenly distributed in the polishing fluid S, preventing abrasive particle aggregation. Evenly distributed abrasive can more effectively contact the surface of the silicon wafer W, improving the uniformity and consistency of the polishing effect. Surfactants reduce the surface tension of the polishing fluid S, making it easier to spread on the surface of the silicon wafer W, increasing the contact area between the polishing fluid S and the surface of the silicon wafer W. The complexing agent can form stable complexes with the metal ions in the polishing slurry S, preventing the precipitation and exudation of metal ions. Water, as the main solvent of the polishing slurry S, can dissolve and disperse the various components mentioned above, forming a homogeneous solution.

[0036] In some embodiments of the present invention, the formulation of the polishing slurry S may include: the particle size of the abrasive, the mass percentage of the abrasive, the mass percentage of the oxidant, the mass percentage of the dispersant, the mass percentage of the surfactant, the mass percentage of the complexing agent, and the pH value of the polishing slurry S. It should be noted here what the effects of these parameters are.

[0037] The abrasive grain size directly affects the flatness of the silicon wafer surface. Coarser abrasive grains are suitable for initial removal of larger surface irregularities, quickly reducing surface roughness, but may produce deeper scratches under high pressure or high rotational speed. Finer abrasive grains are suitable for fine polishing, improving surface smoothness and reducing scratches, but the polishing speed is relatively slower. The abrasive mass percentage determines the concentration of abrasive in the polishing slurry. A higher abrasive mass percentage can improve polishing efficiency and quickly remove surface material, but may increase the risk of surface scratches. A lower abrasive mass percentage can reduce scratches and improve surface quality, but the polishing speed is slower. The oxidant mass percentage affects the chemical reactivity of the polishing slurry. A higher oxidant mass percentage can enhance the chemical reaction, effectively removing the oxide layer and other impurities from the silicon wafer surface, improving surface cleanliness. However, excessively high oxidant concentrations may corrode the silicon wafer surface. The dispersant mass percentage affects the uniform distribution of abrasive in the polishing slurry. A higher dispersant percentage can prevent abrasive particle aggregation, ensuring the uniformity and stability of the polishing slurry and reducing surface defects. However, excessively high dispersant concentrations may increase the viscosity of the polishing slurry, affecting its flowability. The surfactant percentage affects the surface tension and wettability of the polishing slurry. A higher surfactant percentage can reduce the surface tension of the polishing slurry, making it easier to spread on the silicon wafer surface, increasing the contact area between the polishing slurry and the silicon wafer surface, and reducing bubble formation. However, excessively high surfactant concentrations may form excessive foam on the silicon wafer surface, affecting the polishing effect. The complexing agent percentage affects the chemical stability of the polishing slurry. A higher complexing agent percentage can form stable complexes with metal ions in the polishing slurry, preventing the precipitation and exudation of metal ions and extending the service life of the polishing slurry. However, excessively high complexing agent concentrations may affect the pH value of the polishing slurry, affecting the balance of the chemical reaction. The pH value of the polishing slurry affects the activity and balance of the chemical reaction. An appropriate pH value can increase the activity of the oxidant, enhance the effect of the chemical reaction, and reduce corrosion to the silicon wafer surface.

[0038] In some embodiments of the present invention, the abrasive can be SiO2, the oxidant can be H2O2, the dispersant can be sodium polyacrylate, the surfactant can be fatty alcohol polyoxyethylene ether, and the complexing agent can be ethylenediaminetetraacetic acid.

[0039] SiO2 abrasives have a uniform particle size distribution, ensuring uniform grinding during the polishing process. This helps reduce scratches and unevenness on the silicon wafer surface, improving flatness. H2O2, as a strong oxidizing agent, effectively removes the oxide layer and other impurities from the silicon wafer surface. It softens the surface material through a chemical reaction, making it easier for the abrasive to remove, while preventing surface re-oxidation and maintaining surface cleanliness and activity. Sodium polyacrylate effectively disperses abrasive particles, preventing particle aggregation and ensuring the uniformity and stability of the polishing slurry. This helps improve the uniformity and consistency of the polishing effect and reduce surface defects. Fatty alcohol polyoxyethylene ether significantly reduces the surface tension of the polishing slurry, making it easier to spread on the silicon wafer surface and increasing the contact area between the polishing slurry and the silicon wafer surface. This not only improves polishing efficiency but also ensures that the effective components in the polishing slurry act more uniformly on the silicon wafer surface. Ethylenediaminetetraacetic acid (EDTA) forms stable complexes with metal ions in the polishing slurry, preventing the precipitation and exudation of metal ions. This not only improves the chemical stability of the polishing slurry but also ensures the effectiveness of the oxidant and other chemical components, extending the service life of the polishing slurry.

[0040] In some embodiments of the present invention, providing a polishing slurry S with a corresponding formulation in double-sided polishing, based on a pressure range and a speed range, may include: determining the required content of each component in the polishing slurry S according to the pressure range and the speed range, and configuring the polishing slurry S according to the determined content.

[0041] Traditional polishing slurry formulations typically focus on a single characteristic parameter, such as abrasive particle size. This single-parameter approach often fails to achieve good flatness and particle size distribution of silicon wafers (W) under complex polishing conditions. This invention determines the content of each component; that is, by comprehensively controlling the multi-scale characteristic parameters of the polishing slurry (S), including abrasive particle size, abrasive mass percentage, oxidant mass percentage, dispersant mass percentage, surfactant mass percentage, complexing agent mass percentage, and pH value, the performance of the polishing slurry can be more comprehensively optimized to adapt to different polishing conditions. By precisely controlling the multi-scale characteristics of the polishing slurry (S), good polishing results can be maintained consistently across different pressure and rotational speed ranges.

[0042] To determine the required content of each component in the polishing slurry S, one can look up the formula corresponding to the monitored pressure and rotation speed by referring to a table, or one can use a model to output the formula corresponding to the monitored pressure and rotation speed.

[0043] Taking the table lookup as an example, Table 1 below shows the correspondence between polishing fluid formulas and operating conditions: Table 1 pressurization range Rotation speed range Abrasive particle size / nm Abrasive / % Oxidizing agent / % dispersant / % surfactants / % Complexing agents / % pH value 1 Excessive pressure Excessive speed 20~25 5~10 0.2~0.4 6~7 4~5 0.8~1.0 8.0 2 20~25 5~10 0.4~0.8 5~6 3~4 0.5~0.8 8.0 3 20~25 5~10 0.8~1.0 4~5 2~3 0.2~0.5 8.0 4 Excessive pressure Appropriate speed 25~30 10~15 0.2~0.4 6~7 4~5 0.8~1.0 8.5 5 25~30 10~15 0.4~0.8 5~6 3~4 0.5~0.8 8.5 6 25~30 10~15 0.8~1.0 4~5 2~3 0.2~0.5 8.5 7 Excessive pressure Too low speed 30~35 15~20 0.2~0.4 6~7 4~5 0.8~1.0 9.0 8 30~35 15~20 0.4~0.8 5~6 3~4 0.5~0.8 9.0 9 30~35 15~20 0.8~1.0 4~5 2~3 0.2~0.5 9.0 10 Appropriate pressure Excessive speed 35~40 5~10 0.2~0.4 6~7 4~5 0.8~1.0 9.5 11 35~40 5~10 0.4~0.8 5~6 3~4 0.5~0.8 9.5 12 35~40 5~10 0.8~1.0 4~5 2~3 0.2~0.5 9.5 13 Appropriate pressure Appropriate speed 40~45 10~15 0.2~0.4 6~7 4~5 0.8~1.0 10.0 14 40~45 10~15 0.4~0.8 5~6 3~4 0.5~0.8 9.0 15 40~45 10~15 0.8~1.0 4~5 2~3 0.2~0.5 9.0 16 Appropriate pressure Too low speed 45~60 15~20 0.2~0.4 6~7 4~5 0.8~1.0 10.5 17 45~60 15~20 0.4~0.8 5~6 3~4 0.5~0.8 9.0 18 45~60 15~20 0.8~1.0 4~5 2~3 0.2~0.5 9.0 19 Too little pressure Excessive speed 60~70 5~10 0.2~0.4 6~7 4~5 0.8~1.0 11.0 20 60~70 5~10 0.4~0.8 5~6 3~4 0.5~0.8 9.0 twenty one 60~70 5~10 0.8~1.0 4~5 2~3 0.2~0.5 9.0 twenty two Too little pressure Appropriate speed 70~80 10~15 0.2~0.4 6~7 4~5 0.8~1.0 11.5 twenty three 70~80 10~15 0.4~0.8 5~6 3~4 0.5~0.8 9.0 twenty four 70~80 10~15 0.8~1.0 4~5 2~3 0.2~0.5 9.0 25 Too little pressure Too low speed 80~90 15~20 0.2~0.4 6~7 4~5 0.8~1.0 12.0 26 80~90 15~20 0.4~0.8 5~6 3~4 0.5~0.8 12.0 27 80~90 15~20 0.8~1.0 4~5 2~3 0.2~0.5 12.0

[0044] Table 1 lists the operating conditions, including pressure and rotational speed ranges. The pressure range is further divided into three sub-ranges: "excessive pressure," "suitable pressure," and "excessive pressure," with specific values ​​of 800 daN ~ 1000 daN, 1000 daN ~ 1400 daN, and 1400 daN ~ 1700 daN, respectively. Similarly, the rotational speed range is divided into three sub-ranges: "excessive speed," "suitable speed," and "excessive speed," with specific values ​​of 20 rpm ~ 25 rpm, 25 rpm ~ 35 rpm, and 35 rpm ~ 40 rpm, respectively. The polishing fluid formulation includes abrasive particle size, abrasive mass percentage, oxidant mass percentage, dispersant mass percentage, surfactant mass percentage, complexing agent mass percentage, and pH value. The remaining component is water.

[0045] Table 1 lists the polishing fluid formulations (numbers 1-27) for different pressure and rotation speed ranges. Table 2, with its polishing effect evaluation tables (numbers 1-27), shows the specific evaluation results of surface roughness, flatness, particle size distribution, and surface quality achieved by the corresponding formulations during actual polishing. This clearly reflects the impact of different formulations on the polishing effect. Table 2 Surface roughness / nm Flatness / GBIR (μm) Particle level / ea (measured from 60nm) Surface quality level Flatness level Surface particle level 1 0.543 0.204 8 high high high 2 0.679 0.389 twenty one middle middle Low 3 0.693 0.462 26 middle Low Low 4 0.623 0.468 twenty one middle Low Low 5 0.512 0.196 7 high high high 6 0.609 0.329 15 middle middle middle 7 0.643 0.509 26 middle Low Low 8 0.637 0.496 28 middle Low Low 9 0.541 0.215 10 high high high 10 0.486 0.167 7 high high high 11 0.579 0.351 16 high middle middle 12 0.653 0.431 twenty four middle Low Low 13 0.516 0.346 11 high middle high 14 0.453 0.142 6 high high high 15 0.547 0.381 18 high middle middle 16 0.539 0.473 19 middle Low middle 17 0.506 0.391 17 middle middle middle 18 0.481 0.213 9 high high high 19 0.516 0.289 18 middle middle middle 20 0.429 0.141 8 high high high twenty one 0.679 0.334 13 Low middle middle twenty two 0.455 0.161 7 high high high twenty three 0.573 0.314 16 middle middle middle twenty four 0.616 0.296 19 Low middle middle 25 0.701 0.412 31 Low Low Low 26 0.664 0.382 27 Low middle Low 27 0.543 0.206 10 high high high

[0046] By combining Tables 1 and 2, polishing slurry formulations corresponding to different pressure and rotation speed ranges can be selected to achieve the best polishing effect. For example, for the pressure and rotation speed ranges corresponding to numbers 1 to 3 in Table 1, referring to the evaluation results in Table 2, it can be found that number 1 has the best polishing effect. Therefore, the polishing slurry formulation corresponding to number 1 in Table 1 can be selected to ensure that the optimal polishing quality is obtained under these operating conditions.

[0047] Taking model output as an example, a model for predicting polishing slurry formulations based on pressure and rotation speed can be obtained through training with a large amount of historical data. This model comprehensively considers the input pressure and rotation speed, and based on the correlation between different conditions, formulations, and polishing effects in historical data, it derives the recommended content range of each component under current operating conditions to achieve the best polishing effect, such as improving surface finish and reducing particulate contamination. By using this formulation, the polishing process can be better adapted to current command parameters, thereby improving polishing quality and production efficiency.

[0048] The aforementioned tables can be obtained by accumulating technical data. During the polishing process, sensors are used to monitor pressure and rotation speed in real time, and the corresponding polishing fluid formulation parameters and polishing effect evaluation data are recorded. Through steps such as data classification, correlation analysis, and trend analysis, the range of formulation parameters corresponding to the optimal polishing effect under different operating conditions is determined, and a table is constructed based on this, with the corresponding data entered. In addition, new data can be continuously accumulated to update the tables and supplement new information; on the other hand, data can be corrected through experiments to optimize the formulation and add detailed information, making it more comprehensive and accurate in guiding production.

[0049] The aforementioned models can, for example, first collect and preprocess historical data, select appropriate model algorithms based on the characteristics of the data, train the model using a training set, and then verify and evaluate the model's performance through methods such as test set evaluation and cross-validation to determine the optimal model. Furthermore, the model can be updated through incremental learning, hyperparameters can be tuned, and different models can be merged to introduce new features, thereby improving the model's predictive ability and practicality, making it better suited to production needs.

[0050] In some embodiments of the present invention, providing a polishing fluid S with a corresponding formulation in double-sided polishing, based on a pressure range and a speed range, may include providing the polishing fluid S with a corresponding formulation in double-sided polishing when the pressure is within the pressure range and the rotational speed is within the pressure range for a duration greater than or equal to a predetermined duration.

[0051] This invention adjusts the polishing slurry formulation only when the duration of pressure and rotation speed is greater than or equal to the predetermined duration. This reduces the frequency of formulation adjustments, lowering operational complexity and cost. Since adjustments are only made under specific conditions without requiring further formulation changes, the operation process is simplified, improving production efficiency. Within the predetermined duration, the polishing slurry formulation remains stable, ensuring the flatness and particle level of the silicon wafer surface. Even in cases where pressure and rotation speed fluctuate but the changed pressure and rotation speed are less than the predetermined duration, the adverse effects on polishing are minimal due to the shorter duration, thus ensuring a high-quality polishing effect.

[0052] Referring to Figure 3, this embodiment of the invention also provides a silicon wafer processing apparatus 1 for use in the double-sided polishing of silicon wafer W. The silicon wafer processing apparatus 1 may include: Monitoring unit 10 is used to monitor in real time the pressure applied to the silicon wafer W and the rotational speed of the polishing pad 2 used to polish the silicon wafer W during the double-sided polishing process; The classification unit 20 is used to classify pressure into one of a preset plurality of pressure ranges and to classify rotation speed into one of a preset plurality of speed ranges; Supply unit 30, which is used to provide polishing fluid S with a corresponding formula in double-sided polishing according to the pressure range and the speed range.

[0053] The silicon wafer processing apparatus 1 of the present invention monitors the pressure and rotation speed during the polishing process in real time through the monitoring unit 10, and the supply unit 30 provides polishing fluid S with a corresponding formula according to the monitoring results. This dynamic adjustment ensures that the characteristics of the polishing fluid S match the operating conditions, so that the silicon wafer W maintains excellent flatness and particle level even when the pressure and speed fluctuate, significantly improving the stability of polishing quality.

[0054] In some embodiments of the present invention, referring to FIG3, the silicon wafer processing apparatus 1 may further include: Determining unit 40, which is used to determine the required content of each component in polishing fluid S according to the pressure range and the speed range classified accordingly; Configuration unit 50, which is used to configure polishing liquid S according to the determined content.

[0055] This invention determines the content of each component in the polishing slurry S through a determining unit 40, and a configuring unit 50 configures the polishing slurry S accordingly. This achieves precise control over the multi-scale characteristics of the polishing slurry S, ensuring excellent polishing results under different pressures and rotational speeds, and comprehensively optimizing the performance of the polishing slurry to adapt to varying polishing conditions.

[0056] While the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the specific embodiments described and shown herein. Various modifications to the exemplary embodiments can be made by those skilled in the art without departing from the scope defined in the claims.

[0057] The features mentioned and / or shown in the above description of exemplary embodiments of the present invention can be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. These combined or substituted technical solutions should also be considered to be included within the scope of protection of the present invention.

[0058] S101~S103: Procedure Flow 1: Silicon wafer processing equipment 2: Polishing pad 10: Monitoring Unit 20: Classification Unit 30: Supply Unit 40: Determine the unit 50: Configuration Unit W: Silicon wafer X: Axis S: Polishing liquid

Claims

1. A silicon wafer processing method for use in double-sided polishing of silicon wafers, comprising the steps of: During the double-sided polishing process, the pressure applied to the silicon wafer and the rotational speed of the polishing pad polishing the silicon wafer are monitored in real time; the pressure is classified into one of a plurality of preset pressure ranges, and the rotational speed is classified into one of a plurality of preset speed ranges; a polishing fluid with a corresponding formulation is provided in the double-sided polishing process according to the pressure range and the speed range to which it is classified; wherein the pressure range is divided into a total pressure range of 800 daN to 1700 daN, and the speed range is divided into a total speed range of 20 rpm to 40 rpm.

2. The silicon wafer processing method as described in claim 1, wherein, The pressure ranges defined by the total pressure range are: 800 daN to 1000 daN, 1000 daN to 1400 daN, and 1400 daN to 1700 daN, and the speed ranges defined by the total speed range are: 20 rpm to 25 rpm, 25 rpm to 35 rpm, and 35 rpm to 40 rpm.

3. The silicon wafer processing method as described in any one of claims 1 to 2, wherein the polishing fluid comprises abrasive, oxidant, dispersant, surfactant, complexing agent and water.

4. The silicon wafer processing method as described in claim 3, wherein the polishing slurry formulation comprises: The particle size of the abrasive, the mass percentage of the abrasive, the mass percentage of the oxidant, the mass percentage of the dispersant, the mass percentage of the surfactant, the mass percentage of the complexing agent, and the pH value of the polishing fluid.

5. The silicon wafer processing method as described in claim 3, wherein the abrasive is SiO2 (silicon dioxide), the oxidant is H2O2 (hydrogen peroxide), the dispersant is sodium polyacrylate, the surfactant is fatty alcohol polyoxyethylene ether, and the complexing agent is ethylenediaminetetraacetic acid.

6. The silicon wafer processing method as described in any one of claims 1 to 2, wherein providing the polishing fluid with the corresponding formulation in the double-sided polishing, according to the pressure range and the speed range to which it is classified, comprises: The required content of each component in the polishing fluid is determined according to the pressure range to which it is classified and the speed range to which it is classified, and the polishing fluid is prepared according to the content.

7. A silicon wafer processing method as described in any one of claims 1 to 2, wherein providing the polishing fluid with the corresponding formulation in the double-sided polishing, according to the pressure range to which it is classified and the speed range to which it is classified, comprises: The polishing fluid is provided in the double-sided polishing when the pressure is within the range to which it is classified and the rotational speed is within the range to which it is classified for a duration greater than or equal to a predetermined duration.

8. A silicon wafer processing apparatus for use in double-sided polishing of silicon wafers, comprising: The system includes: a monitoring unit for real-time monitoring of the pressure applied to the silicon wafer and the rotational speed of the polishing pad used to polish the silicon wafer during the double-sided polishing process; a classification unit for classifying the pressure into one of a plurality of preset pressure ranges and the rotational speed into one of a plurality of preset speed ranges; and a supply unit for providing polishing fluid with a corresponding formulation in the double-sided polishing process according to the pressure range and speed range to which the fluid is classified; wherein the pressure range is defined by a total pressure range of 800 daN to 1700 daN and the speed range is defined by a total speed range of 20 rpm to 40 rpm.

9. The silicon wafer processing apparatus as claimed in claim 8, wherein the silicon wafer processing apparatus further comprises: A determining unit is configured to determine the required content of each component in the polishing slurry based on the pressure range and the speed range to which it is classified; and a configuring unit is configured to configure the polishing slurry according to the content.

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