Polishing solution compensation device for semiconductor substrate CMP (chemical mechanical polishing)

Abstract

The invention discloses a polishing solution compensation device for semiconductor substrate CMP (chemical mechanical polishing), and relates to the technical field of polishing solution compensation. The device comprises a cabinet, a protective cover, a polishing pad, a spray head, a mixed liquid storage tank, a liquid supplementing assembly and a polishing liquid intelligent regulation and control system, and is composed of a concentration detection and analysis module, a liquid supplementing decision and control module, a stirring coordinated regulation module and a state monitoring and early warning module. The concentration detection and analysis module is used for collecting concentration signals of different areas in the tank through multiple groups of concentration sensing units, analyzing the concentration change trend through a multi-dimensional data fusion algorithm in combination with CMP process dynamic parameters and pre-judging deviation; and the liquid supplementing decision and control module calculates the target liquid supplementing amount and rate through a self-adaptive PID control algorithm based on the concentration deviation data, and controls the liquid supplementing assembly to switch the liquid supplementing type. According to the device, precision and intelligence of polishing solution compensation are achieved, and the problems that in an existing device, a polishing solution is prone to layering and precipitating, active ingredients deteriorate, concentration dynamic response lags behind, and substrate polishing consistency deviates are solved.

Description

Technical Field

[0001] This invention relates to the relevant technical field, and in particular to a polishing slurry compensation device for CMP polishing of semiconductor substrates. Background Technology

[0002] In semiconductor chip manufacturing, chemical mechanical polishing (CMP) is a core process for achieving substrate surface planarization. It removes excess material from the substrate surface through the synergistic effect of chemical etching by the polishing slurry and mechanical abrasion by the polishing pad, resulting in a high-precision, highly flat surface morphology. This directly determines the processing quality of subsequent photolithography, etching, and other processes, thus affecting the final chip performance and yield. As semiconductor devices evolve towards higher density and smaller dimensions, the requirements for precise control of the CMP process are becoming increasingly stringent. The concentration stability and mixing uniformity of the polishing slurry, as the core medium, have become key factors restricting the improvement of process precision.

[0003] Existing CMP polishing slurry compensation devices mostly employ a pre-mixed polishing slurry injection method. However, polishing slurries are often multi-component complex systems, which are prone to stratification and precipitation due to density differences during static storage, resulting in uneven concentrations between the upper and lower layers. Simultaneously, some active ingredients may undergo premature chemical reactions or deteriorate due to changes in ambient temperature or contact with the tank, affecting the original performance of the polishing slurry. Furthermore, the concentration control of traditional devices is mostly passive, lacking linkage and adaptation to dynamic process parameters. This leads to problems such as lag in dynamic concentration response and insufficient coordination between replenishment and stirring, ultimately resulting in inconsistent polishing of semiconductor substrates and failing to meet the requirements of high-precision chip manufacturing. Therefore, there is an urgent need for a polishing slurry compensation device for CMP polishing of semiconductor substrates to solve the above problems. Summary of the Invention

[0004] This invention provides a polishing slurry compensation device for CMP polishing of semiconductor substrates, which solves the technical problems in existing CMP polishing slurry compensation devices for semiconductor substrates, such as easy stratification and precipitation of polishing slurry, premature deterioration of active ingredients leading to uneven concentration, delayed passive response of concentration control, and insufficient coordination between replenishment and stirring, which in turn cause deviations in the consistency of substrate polishing.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: a polishing slurry compensation device for CMP polishing of semiconductor substrates, including a cabinet, a protective cover on the top surface of the cabinet, multiple double-leaf glass doors on the periphery of the protective cover, a polishing pad rotatably mounted in the center of the top surface of the cabinet, a nozzle for spraying polishing slurry on one side of the top surface of the polishing pad, a mixing reservoir for supplying polishing slurry to the nozzle installed inside the cabinet, a replenishment component on one side of the mixing reservoir, and a polishing slurry intelligent control system, which consists of a concentration detection and analysis module, a replenishment decision and control module, a stirring and coordination adjustment module, and a status monitoring and early warning module;

[0006] The concentration detection and analysis module collects polishing fluid concentration signals in different areas of the tank through multiple concentration sensing units spaced apart along the height of the mixing tank. At the same time, it combines CMP process dynamic parameters and adopts a multi-dimensional data fusion algorithm to analyze the polishing fluid concentration change trend in real time and predict the concentration deviation.

[0007] The fluid replenishment decision and control module calculates the target fluid replenishment volume and replenishment rate based on the concentration deviation data output by the concentration detection and analysis module, and then controls the fluid replenishment components to achieve precise switching of fluid replenishment type and closed-loop control of the fluid replenishment process.

[0008] The stirring coordination adjustment module dynamically matches gradient stirring parameters based on the replenishment volume and type determined by the replenishment decision and control module, thereby achieving adaptive matching between replenishment and stirring actions.

[0009] The status monitoring and early warning module collects equipment operating parameters and process execution status information in real time, and triggers an early warning when the parameters exceed the preset safety range or an abnormality occurs.

[0010] Preferably, the top surface of the mixing tank is provided with at least one threaded hole, and a concentration sensor is screwed into the threaded hole. The concentration sensor constitutes the concentration sensing unit of the concentration detection and analysis module. A sealing and protective structure for preventing polishing fluid leakage is provided at the mating surface between the threaded hole and the concentration sensor.

[0011] Preferably, a suction pipe is fixedly connected to one side of the nozzle, and the end of the suction pipe away from the nozzle extends to the bottom surface of the mixing storage tank. A first pump is installed on one side of the top surface of the nozzle, and the input end of the first pump is connected and fixed to the suction pipe.

[0012] Preferably, the replenishment assembly includes two cameras symmetrically installed on the top surface inside the protective cover, a stock solution tank and a diluent tank symmetrically arranged on one side of the mixing storage tank, two peristaltic pumps respectively installed on the top surfaces of the stock solution tank and the diluent tank, delivery pipes adapted to pass through the pump heads of each peristaltic pump, and a two-inlet, one-way solenoid valve fixedly connected to the end of the two delivery pipes away from the tank body; the ends of the two delivery pipes near the tank body extend into the inside of the stock solution tank and the diluent tank respectively, and the output port of the two-inlet, one-way solenoid valve extends into the inside of the mixing storage tank.

[0013] Preferably, the output port of the two-in-one-out solenoid valve is connected to a fixed static mixer, which is located inside the mixing storage tank. The top surfaces of the raw liquid tank, the diluent tank, and the mixing storage tank are all equipped with level gauges. The level gauges are connected to the concentration detection and analysis module to transmit the liquid level data of each tank to the module. The bottom side of one side of the raw liquid tank, the diluent tank, and the mixing storage tank is provided with an internally threaded valve pipe.

[0014] Preferably, a motor is fixedly installed in the middle of the top surface of the mixing tank, and a rotating shaft is fixedly connected to the output shaft of the motor. The end of the rotating shaft away from the motor extends into the interior of the mixing tank and rotates with the inner wall of the tank. At least one set of propellers is fixedly connected to the rotating shaft.

[0015] Preferably, the CMP process dynamic parameters collected by the concentration detection and analysis module include polishing pressure, polishing pad rotation speed and polishing time. These process dynamic parameters are acquired through corresponding pressure sensors, rotation speed sensors and timing modules, and all of them are connected to the concentration detection and analysis module.

[0016] Preferably, the adaptive PID control algorithm achieves real-time correction of the replenishment volume by dynamically adjusting the proportional coefficient, integral coefficient, and derivative coefficient. Specifically, when the concentration deviation value is greater than the preset deviation threshold, the proportional coefficient is increased to accelerate the replenishment response speed; when the concentration change trend tends to be stable, the integral coefficient is adjusted to reduce the steady-state error; when the risk of concentration fluctuation is predicted, the derivative coefficient is used to suppress the expansion of the deviation in advance. The gradient stirring parameters include stirring speed and stirring duration, and their setting logic is as follows: in the initial stage of replenishment, low-speed stirring is used to avoid splashing of polishing liquid; in the middle stage of replenishment, the speed is increased according to the replenishment volume gradient to promote mixing; after replenishment, medium-high speed stirring is maintained for a preset duration to ensure concentration uniformity.

[0017] Preferably, the status monitoring and early warning module provides early warning methods including audible and visual early warning and remote transmission of abnormal information. The audible and visual early warning is achieved through an audible and visual early warning component installed on the outside of the protective cover, and the remote transmission of abnormal information is achieved through a built-in communication module. The abnormal information monitored by the status monitoring and early warning module includes excessive deviation of polishing fluid concentration, abnormal liquid level in each tank, equipment component malfunction, and abnormal process execution status.

[0018] The beneficial effects of this invention are:

[0019] 1. This solution dynamically matches gradient stirring parameters through a stirring coordination adjustment module, and combines continuous stirring by the motor, shaft and propeller to achieve adaptive matching between liquid replenishment and stirring. At the same time, with the help of a two-inlet one-way solenoid valve, static mixer and the linkage replenishment of the original liquid tank and diluent tank, the polishing liquid can be mixed and its composition adjusted online in real time, avoiding the stratification and precipitation and deterioration of active ingredients caused by long-term storage of polishing liquid, and significantly improving the mixing uniformity and performance stability of polishing liquid.

[0020] 2. In this solution, the concentration detection and analysis module collects concentration signals from different areas through multiple concentration sensing units. Combined with dynamic parameters of the CMP process, it analyzes the concentration change trend and predicts deviations through a multi-dimensional data fusion algorithm. The replenishment decision and control module, based on the deviation data, accurately calculates the replenishment volume and rate through an adaptive PID control algorithm, controls the replenishment component to switch replenishment types, and forms a closed-loop regulation, which greatly improves the timeliness and accuracy of concentration regulation and avoids polishing quality problems caused by concentration deviations.

[0021] 3. The status monitoring and early warning module in this solution collects equipment operating parameters and process execution status information in real time, covering multiple dimensions of anomalies such as polishing slurry concentration deviation, liquid levels in each tank, operating status of equipment components, and process parameters. Through audible and visual warnings and remote transmission of anomaly information, it promptly alerts operators to handle the issues and records anomaly details for traceability. Combined with the protection and support of cabinets and protective covers, it effectively reduces the impact of equipment failures on the process, ensures the continuous and stable polishing process, and improves the consistency and yield of semiconductor substrate polishing.

[0022] In summary, this invention, through the coordinated operation of the four modules of the polishing slurry intelligent control system and the synergistic cooperation of various structural components, addresses the problems of polishing slurry stratification and sedimentation, deterioration of active ingredients, lag in concentration response, and deviation in polishing consistency that exist in traditional devices from three core dimensions: uniformity of polishing slurry mixing, precision of concentration control, and comprehensiveness of anomaly monitoring. It achieves precise and intelligent operation of polishing slurry compensation, significantly improving the performance stability of polishing slurry and the precision, safety, and continuity of CMP polishing process. Attached Figure Description

[0023] Figure 1 This is a first-view schematic diagram of the overall structure proposed in this invention;

[0024] Figure 2 This is a first-view schematic diagram of the overall cross-sectional structure of the cabinet proposed in this invention;

[0025] Figure 3 This is a second-view schematic diagram of the overall cross-sectional structure of the cabinet proposed in this invention;

[0026] Figure 4 This is a schematic cross-sectional view of the overall structure of the mixing storage tank proposed in this invention;

[0027] Figure 5 This is a block diagram showing the overall module connection relationship of the intelligent control system for polishing fluid proposed in this invention;

[0028] Figure 6 This is a block diagram illustrating the principle of the concentration detection and analysis module proposed in this invention.

[0029] Figure 7 This is a block diagram illustrating the liquid replenishment-stirring synergistic control principle proposed in this invention;

[0030] Figure 8 This is a block diagram illustrating the principle of the status monitoring and early warning module proposed in this invention.

[0031] In the diagram: 1. Cabinet; 2. Protective cover; 3. Double-leaf glass door; 4. Polishing pad; 5. Nozzle; 6. Mixing tank; 7. Concentration sensor; 8. Level gauge; 9. Suction pipe; 10. First pump; 11. Camera; 12. Stock solution tank; 13. Diluent tank; 14. Peristaltic pump; 15. Delivery pipe; 16. Two-way solenoid valve; 17. Static mixer; 18. Internally threaded valve pipe. Detailed Implementation

[0032] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example: See Figures 1 to 8 As shown, a polishing slurry compensation device for CMP polishing of semiconductor substrates according to the present invention includes a cabinet 1, which is made of 304 stainless steel. The top surface of the cabinet 1 is covered with a protective cover 2, and multiple double-leaf glass doors 3 are provided around the protective cover 2. A polishing pad 4 is rotatably mounted in the middle of the top surface of the cabinet 1. A nozzle 5 for spraying polishing slurry is provided on one side of the top surface of the polishing pad 4. A mixing reservoir 6 for supplying polishing slurry to the nozzle 5 is installed inside the cabinet 1. A replenishment component is provided on one side of the mixing reservoir 6. The above structure forms the basic framework of the polishing slurry compensation device, providing a reliable carrier for polishing operations and the installation of various functional components.

[0034] The present invention also includes a polishing fluid intelligent control system, which establishes signal connections with the mixing storage tank 6, the replenishment component and the nozzle 5 respectively. The polishing fluid intelligent control system consists of a concentration detection and analysis module, a replenishment decision and control module, a stirring and coordination adjustment module and a status monitoring and early warning module.

[0035] The concentration detection and analysis module collects polishing fluid concentration signals from different areas within the mixing tank 6 using multiple concentration sensing units spaced at intervals along the height of the tank. Simultaneously, it combines CMP process dynamic parameters with a multi-dimensional data fusion algorithm, the formula of which is as follows: The concentration of the fused polishing slurry was calculated. The system analyzes the real-time trend of polishing slurry concentration changes and predicts deviations. Based on the concentration deviation data, the replenishment decision and control module calculates the target replenishment volume and rate using an adaptive PID control algorithm. The algorithm formula is as follows: The system controls the precise switching of the replenishment type by the replenishment component; the stirring and coordination adjustment module dynamically matches the gradient stirring parameters according to the replenishment parameters to achieve adaptive matching between replenishment and stirring; the status monitoring and early warning module monitors the equipment and process status in real time and triggers an early warning when abnormalities occur, thus achieving precise and intelligent compensation of polishing fluid and solving the problems of lag in dynamic concentration response and deviation in polishing consistency.

[0036] Specifically, the top surface of the mixing tank 6 has at least one threaded hole, and a concentration sensor 7 is screwed into the threaded hole. The concentration sensor 7 constitutes the concentration sensing unit of the concentration detection and analysis module. A sealing and protective structure for preventing polishing fluid leakage is provided at the mating surface between the threaded hole and the concentration sensor 7.

[0037] Specifically, a suction pipe 9 is fixedly connected to one side of the nozzle 5. The end of the suction pipe 9 away from the nozzle 5 extends to the bottom surface of the mixing storage tank 6. A first pump 10 is installed on one side of the top surface of the nozzle 5. The first pump 10 adopts a ZX series micro centrifugal pump. The input end of the first pump 10 is connected and fixed to the suction pipe 9. The first pump 10 establishes a signal connection with the polishing liquid intelligent control system and is controlled by the control commands output by it to achieve adaptive adjustment of the spray flow rate.

[0038] Specifically, the replenishment assembly includes two cameras 11 symmetrically installed on the top surface inside the protective cover 2, a stock solution tank 12 and a diluent tank 13 symmetrically arranged on one side of the mixing storage tank 6, two peristaltic pumps 14 respectively installed on the top surfaces of the stock solution tank 12 and the diluent tank 13, delivery pipes 15 adapted to pass through the pump heads of each peristaltic pump 14, and a two-inlet one-way solenoid valve 16 fixedly connected to the end of the two delivery pipes 15 away from the tank body; the ends of the two delivery pipes 15 near the tank body extend into the inside of the stock solution tank 12 and the diluent tank 13 respectively, and the output port of the two-inlet one-way solenoid valve 16 extends into the inside of the mixing storage tank 6. The peristaltic pumps 14 and the two-inlet one-way solenoid valve 16 are both connected to the replenishment decision and control module, and are controlled by it to realize the start and stop of replenishment, the switching of replenishment type, and the adjustment of replenishment rate.

[0039] Specifically, a static mixer 17 is fixedly connected to the output port of the two-in-one-out solenoid valve 16. The static mixer 17 is located inside the mixing storage tank 6. A level gauge 8 is installed on the top surface of the raw liquid tank 12, the diluent tank 13, and the mixing storage tank 6. The level gauge 8 establishes a signal connection with the concentration detection and analysis module to transmit the liquid level data of each tank to the module. An internally threaded valve pipe 18 is provided on the bottom side of one side of the raw liquid tank 12, the diluent tank 13, and the mixing storage tank 6 to realize the discharge of liquid in the tank and the cleaning of the tank.

[0040] Specifically, a motor is fixedly installed in the middle of the top surface of the mixing tank 6. The output shaft of the motor is coaxially fixedly connected to a rotating shaft. The end of the rotating shaft away from the motor extends into the interior of the mixing tank 6 and rotates with the inner wall of the tank. At least one set of propellers is fixedly connected to the rotating shaft. The motor constitutes the stirring drive component of the stirring coordination adjustment module, establishes a signal connection with the module, and is controlled by it to realize the gradient adjustment of the stirring speed and the precise control of the stirring time.

[0041] The stirring and regulating module controls the motor speed by outputting a pulse width modulation (PWM) signal. The calculation and control logic of the gradient stirring parameters is as follows:

[0042] Let the expected fluid replenishment volume be Q (unit: L), and the fluid replenishment type coefficient be k (specifically, for example, the original fluid). diluent The rated volume of the mixing tank 6 is V (unit: L), and the reference rotation speed is... (Unit: r / min, range of values) ); rotation speed during initial fluid replenishment Stirring time The duty cycle of the PWM signal during this stage ;

[0043] Mid-stage rotation speed during fluid infusion Stirring time The rotation speed increases every 5 seconds. The gradient increases, corresponding to the PWM signal duty cycle increasing accordingly. Gradient adjustment; rotation speed after fluid infusion is completed Stirring time The duty cycle of the PWM signal during this stage is ;

[0044] The motor speed is fed back in real time via an encoder. The stirring and co-regulating module corrects the PWM signal duty cycle based on the deviation between the feedback value and the target speed using a proportional control algorithm. The deviation correction formula is as follows: ,in This is the speed correction factor. This is the duty cycle correction amount. This indicates the target speed of the stirring motor. This indicates the actual feedback speed of the stirring motor, and this correction ensures the speed control accuracy is ±5 r / min.

[0045] Specifically, the CMP process dynamic parameters collected by the concentration detection and analysis module include polishing pressure P (unit: kPa) and polishing pad rotation speed. (Unit: r / min) and polishing time t (unit: min);

[0046] The pressure sensor is installed in the contact area between the polishing head and the substrate, the speed sensor is installed at the drive shaft end of polishing pad 4, and the timing module is integrated into the concentration detection and analysis module. All three sensors have a data acquisition frequency of [missing information]. The data is transmitted to the concentration detection and analysis module via an RS485 bus; the specific formula for the multi-dimensional data fusion algorithm is as follows: ,in The weighting coefficients of the i-th group of concentration sensing units, These represent the weighting coefficients corresponding to pressure, rotational speed, and duration, respectively. This represents the area concentration value collected by the i-th group of concentration sensing units. This indicates the polishing pressure during the CMP process. This indicates the real-time rotational speed of polishing pad 4, and t indicates the duration of the current polishing process;

[0047] The concentration change trend is predicted using a linear regression algorithm to calculate the trend coefficient. The formula is ,in To predict the time interval (specific values ​​are as follows) ), This represents the concentration of the polishing slurry at time t. , Indicates the change in concentration per unit time; preset trend threshold. (Specifically as follows) ),when The predicted concentration was higher than expected. The predicted concentration was too low. If the concentration is predicted to be within a stable range, this comparison can be used to provide early warning of deviations.

[0048] Specifically, the adaptive PID control algorithm achieves real-time correction of the replenishment volume by dynamically adjusting the proportional coefficient, integral coefficient, and derivative coefficient. The formula for the adaptive PID control algorithm is as follows: ,in This is for adjusting the fluid infusion rate. Let represent the dynamic proportional coefficient, dynamic integral coefficient, and dynamic differential coefficient at time t, respectively. Indicates the concentration deviation value ( , (Preset polishing fluid standard concentration). The integral term representing the concentration deviation (reflecting the cumulative amount of deviation). Represents the integration variable (representing the time node in the integration process). The differential term representing the concentration deviation (reflecting the rate of change of the deviation);

[0049] Set preset deviation threshold Threshold for mass percentage concentration ,when hour, Take the larger value Take the smaller value Choose a moderate value to speed up the response.

[0050] when hour, Take the middle value Take the middle value A moderate value is chosen to balance response speed and steady-state accuracy;

[0051] when hour, Take the smaller value Take the larger value Take a smaller value to reduce steady-state error;

[0052] Target fluid replacement volume ,in The current polishing fluid volume in the mixing storage tank 6 (calculated from the data of the level gauge 8). To compensate for the concentration difference of the replenishing medium (stock solution) diluent (Unit: wt%)

[0053] The formula for matching gradient stirring parameters with replenishment volume is as follows: ,in The stirring reference speed (unit: r / min). For the type of fluid replacement, the compatibility factor (stock solution) Take the larger value, diluent Take the smaller value). This is a duration factor; in the initial stage of fluid resuscitation. Pick small proportions Choose the shortest duration; after the fluid resuscitation is completed. Pick large proportions and Positive correlation ensures that the mixing uniformity deviation is ≤0.1wt%.

[0054] Specifically, the status monitoring and early warning module includes an audible and visual early warning component installed on the outside of the protective cover 2 and a built-in communication module. The audible and visual early warning is achieved through the audible and visual early warning component installed on the outside of the protective cover 2. The audible and visual early warning component has a fixed frequency buzzer alarm and a red LED flashing alarm function. The remote transmission of abnormal information is achieved through the built-in communication module.

[0055] Abnormal information includes excessive deviation in polishing fluid concentration, abnormal liquid levels in various tanks, malfunctions in equipment components, and abnormal process execution status;

[0056] The method for determining each anomaly in the abnormal information is as follows:

[0057] Polishing fluid concentration deviation exceeds the standard: The actual concentration value deviates from the standard value by more than the preset threshold, or the concentration change trend exceeds the safe range and continues for a certain period of time;

[0058] Abnormal liquid levels in each tank: the liquid level is higher than 90% of the rated volume of the tank, the liquid level of the mixing storage tank 6 is lower than 15% of the rated volume, or the liquid levels of the original liquid tank 12 and the diluent tank 13 are lower than 10% of the rated volume, or the liquid level changes significantly in a short period of time when not replenishing or spraying.

[0059] Equipment component malfunction: The operating parameters of the pump, solenoid valve, and motor are outside the preset range, or the signal transmission of the sensing components is abnormal;

[0060] Abnormal process execution status: polishing pressure, speed, and duration deviate from the set values, or camera 11 detects uneven polishing liquid spraying, substrate misalignment, or excessive scratches on polishing pad 4; after the abnormality is triggered, the audible and visual warning component will continue to alarm until the abnormality is resolved, and the communication module will simultaneously send a warning containing key information. If not processed, the warning will be repeated periodically.

[0061] The working principle of the polishing slurry compensation device for CMP polishing of semiconductor substrates proposed in this invention is as follows:

[0062] After the device is started, the first pump 10 draws polishing fluid from the mixing tank 6 through the suction pipe 9 and sprays it evenly onto the surface of the polishing pad 4 through the nozzle 5, providing a medium for the chemical mechanical polishing of the semiconductor substrate and ensuring the orderly progress of the polishing process. At the same time, the polishing fluid intelligent control system starts up and enters a closed-loop working mode, with its four core modules working together to achieve precise compensation. The concentration detection and analysis module collects the polishing fluid concentration signals in different areas of the tank in real time through multiple sets of concentration sensors 7 (i.e., concentration sensing units) arranged at intervals along the height of the mixing tank 6. At the same time, it collects dynamic parameters such as polishing pressure, polishing pad 4 rotation speed, and polishing time of the CMP process through pressure sensors, speed sensors, and timing modules. The above data is weighted and fused using a multi-dimensional data fusion algorithm to calculate a precise fused concentration value, thereby analyzing the concentration change trend and predicting deviations, and identifying the risk of concentration anomalies in advance. The level gauge 8 collects the liquid level data of the mixing tank 6, the original liquid tank 12, and the diluent tank 13 in real time and transmits it to the concentration detection and analysis module as an auxiliary judgment basis.

[0063] After receiving the concentration deviation data output by the concentration detection and analysis module and the liquid level data of each tank transmitted by the level gauge 8, the replenishment decision and control module dynamically adjusts the proportional, integral, and derivative coefficients through an adaptive PID control algorithm to accurately calculate the target replenishment volume and replenishment rate. Then, it sends control commands to the replenishment component: the replenishment type of the original liquid in the original liquid tank 12 or the diluent in the diluent tank 13 is switched through the two-in-one-out solenoid valve 16. Then, the peristaltic pump 14 delivers the replenishment liquid to the static mixer 17 through the delivery pipe 15 at the set rate for preliminary mixing, and finally injects it into the mixing storage tank 6 to achieve closed-loop control of the replenishment process. The stirring and coordination adjustment module dynamically matches gradient stirring parameters based on the replenishment volume and type determined by the replenishment decision and control module. It controls the motor on top of the mixing storage tank 6 by outputting a PWM signal, which drives the shaft and propeller to adjust the speed and stirring time according to the logic of "low speed in the early stage of replenishment to prevent splashing, gradient speed increase in the middle stage to promote mixing, and medium-high speed in the later stage to ensure uniformity". At the same time, it combines the real-time speed feedback of the motor encoder to correct the parameters, ensuring that the replenishment and stirring actions are adaptive and matched, and improving the uniformity of the polishing liquid mixing.

[0064] The status monitoring and early warning module collects equipment operating parameters and process execution status information throughout the entire process: concentration sensor 7 monitors polishing fluid concentration deviation, level gauge 8 monitors liquid levels in each tank, sensors collect operating status data for components such as the first pump 10, the two-in-one-out solenoid valve 16, and the motor, and pressure and speed sensors monitor process parameters such as polishing pressure and polishing pad speed 4. Simultaneously, a camera 11 on the inner top surface of the protective cover 2 monitors polishing fluid spraying and substrate polishing status in real time. When parameters exceed preset safety ranges or abnormalities occur, an alarm signal is issued via an audible and visual warning component on the outside of the protective cover 2. Simultaneously, the built-in communication module remotely transmits the abnormal information to the monitoring platform, recording details for traceability. The internally threaded valve pipe 18 allows for the discharge of residual liquid from each tank during equipment maintenance, ensuring convenient cleaning and repair. The entire process, through the coordinated operation of these four modules, combined with the protection and support of the cabinet 1, protective cover 2, and double-leaf glass door 3, achieves precise and intelligent polishing fluid compensation, effectively solving the problems of lag in dynamic concentration response and polishing consistency deviation, ensuring the stability and high precision of the CMP polishing process.

[0065] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A polishing slurry compensation device for CMP polishing of semiconductor substrates, comprising a cabinet (1), a protective cover (2) covering the top surface of the cabinet (1), a plurality of double-leaf glass doors (3) on the periphery of the protective cover (2), a polishing pad (4) rotatably mounted in the center of the top surface of the cabinet (1), a nozzle (5) for spraying polishing slurry on one side of the top surface of the polishing pad (4), a mixing reservoir (6) for supplying polishing slurry to the nozzle (5) installed inside the cabinet (1), and a replenishment component on one side of the mixing reservoir (6), characterized in that, It also includes a polishing fluid intelligent control system, which consists of a concentration detection and analysis module, a replenishment decision and control module, a stirring and coordination adjustment module, and a status monitoring and early warning module. The concentration detection and analysis module collects polishing liquid concentration signals in different areas of the tank through multiple concentration sensing units arranged at intervals along the height direction of the mixing storage tank (6). At the same time, it combines CMP process dynamic parameters and adopts a multi-dimensional data fusion algorithm to analyze the polishing liquid concentration change trend in real time and predict the concentration deviation. The fluid replenishment decision and control module calculates the target fluid replenishment volume and replenishment rate based on the concentration deviation data output by the concentration detection and analysis module, and then controls the fluid replenishment components to achieve precise switching of fluid replenishment type and closed-loop control of the fluid replenishment process. The stirring coordination adjustment module dynamically matches gradient stirring parameters based on the replenishment volume and type determined by the replenishment decision and control module, thereby achieving adaptive matching between replenishment and stirring actions. The status monitoring and early warning module collects equipment operating parameters and process execution status information in real time, and triggers an early warning when the parameters exceed the preset safety range or an abnormality occurs.

2. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 1, characterized in that: The top surface of the mixing tank (6) is provided with at least one threaded hole, and a concentration sensor (7) is screwed into the threaded hole. The concentration sensor (7) constitutes the concentration sensing unit of the concentration detection and analysis module. A sealing and protective structure for preventing polishing liquid leakage is provided at the mating surface of the threaded hole and the concentration sensor (7).

3. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 1, characterized in that: A suction pipe (9) is fixedly connected to one side of the nozzle (5). The end of the suction pipe (9) away from the nozzle (5) extends to the bottom surface of the mixing storage tank (6). A first pump (10) is installed on one side of the top surface of the nozzle (5). The input end of the first pump (10) is connected and fixed to the suction pipe (9).

4. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 1, characterized in that: The replenishment assembly includes two cameras (11) symmetrically installed on the top surface inside the protective cover (2), a stock solution tank (12) and a diluent tank (13) symmetrically arranged on one side of the mixing storage tank (6), two peristaltic pumps (14) respectively installed on the top surface of the stock solution tank (12) and the diluent tank (13), a delivery pipe (15) adapted to pass through the pump head of each peristaltic pump (14), and a two-inlet one-way solenoid valve (16) fixedly connected to the end of the two delivery pipes (15) away from the tank body; the end of the two delivery pipes (15) near the tank body extends into the inside of the stock solution tank (12) and the diluent tank (13) respectively, and the output port of the two-inlet one-way solenoid valve (16) extends into the inside of the mixing storage tank (6).

5. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 4, characterized in that: The output port of the two-in-one-out solenoid valve (16) is connected to a static mixer (17), which is located inside the mixing storage tank (6). The top surfaces of the original liquid tank (12), the diluent tank (13), and the mixing storage tank (6) are all equipped with level gauges (8). The level gauges (8) are connected to the concentration detection and analysis module to transmit the liquid level data of each tank to the module. The bottom side of one side of the original liquid tank (12), the diluent tank (13), and the mixing storage tank (6) is provided with an internally threaded valve pipe (18).

6. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 2, characterized in that: A motor is fixedly installed in the middle of the top surface of the mixing tank (6). The output shaft of the motor is coaxially fixedly connected to a rotating shaft. The end of the rotating shaft away from the motor extends into the interior of the mixing tank (6) and rotates with the inner wall of the tank. At least one set of propellers is fixedly connected to the rotating shaft.

7. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 1, characterized in that: The CMP process dynamic parameters collected by the concentration detection and analysis module include polishing pressure, polishing pad (4) rotation speed and polishing time. The process dynamic parameters are acquired by the corresponding pressure sensor, rotation speed sensor and timing module. The pressure sensor, rotation speed sensor and timing module are all connected to the concentration detection and analysis module.

8. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 1, characterized in that: The adaptive PID control algorithm achieves real-time correction of the replenishment volume by dynamically adjusting the proportional coefficient, integral coefficient, and derivative coefficient. Specifically, when the concentration deviation is greater than the preset deviation threshold, the proportional coefficient is increased to accelerate the replenishment response speed; when the concentration change trend tends to be stable, the integral coefficient is adjusted to reduce the steady-state error; when the risk of concentration fluctuation is predicted, the derivative coefficient is used to suppress the expansion of the deviation in advance. The gradient stirring parameters include stirring speed and stirring duration, and their setting logic is as follows: in the initial stage of replenishment, low-speed stirring is used to avoid splashing of polishing liquid; in the middle stage of replenishment, the speed is increased according to the replenishment volume gradient to promote mixing; after replenishment, medium-high speed stirring is maintained for a preset duration to ensure concentration uniformity.

9. The polishing slurry compensation device for CMP polishing of semiconductor substrates according to claim 1, characterized in that: The warning methods of the status monitoring and early warning module include audible and visual warning and remote transmission of abnormal information. The audible and visual warning is achieved by an audible and visual warning component installed on the outside of the protective cover (2). The remote transmission of abnormal information is achieved by a built-in communication module. The abnormal information monitored by the status monitoring and early warning module includes excessive deviation of polishing fluid concentration, abnormal liquid level in each tank, equipment component operation failure and abnormal process execution status.

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