Cmp pressure control method and system

Abstract

The application relates to the technical field of semiconductor manufacturing equipment, and provides a CMP (Chemical Mechanical Polishing) pressure control method and system.The method comprises the following steps: outputting a wafer loading instruction on a device host interface, moving a polishing head above a wafer loading platform and making the polishing head fall; a controller controls a driving module to extract gas in a central area through a gas pipeline to generate negative pressure required by a process; under the action of the negative pressure, a polyurethane film tightly adsorbs the back surface of a wafer; after a vacuum degree sensor monitors that the negative pressure value meets an adsorption threshold value, the controller determines that the adsorption is successful, the polishing head is lifted and moved above a polishing pad to polish; the self-adaptive distribution of wafer quadrant pressure, the accurate adjustment of wafer edge polishing speed and the effective buffering of polishing head mechanical vibration are realized, and wafer polishing unevenness, edge over-polishing or micro-scratches on the surface are avoided.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing equipment technology, specifically to a CMP pressurization control method and system. Background Technology

[0002] As integrated circuit manufacturing processes continue to evolve towards advanced processes, in order to achieve nanometer-level global flatness in the CMP (chemical mechanical planarization) process, a polishing head is needed on the CMP equipment to load and press down the wafer. In existing technical solutions, when using the polishing head for polishing, the polishing process is usually performed directly using the polishing head, resulting in insufficient polishing accuracy. Summary of the Invention

[0003] This application provides a CMP pressurization control method and system that enables adaptive distribution of pressure in four wafer zones, precise adjustment of wafer edge polishing rate, and effective buffering of mechanical vibration of the polishing head, thereby avoiding uneven wafer polishing, over-polishing of edges, or micro-scratches on the surface.

[0004] A first aspect of this application provides a CMP pressurization control method, the method comprising:

[0005] The device host interface outputs the wafer loading command, and the polishing head moves to the top of the wafer loading stage and then falls.

[0006] The controller controls the start-up drive module to draw gas from the central area through the gas pipeline to generate the negative pressure required for the process.

[0007] Under negative pressure, the polyurethane film tightly adheres to the back side of the wafer. Once the vacuum sensor detects that the negative pressure value meets the adsorption threshold, the controller determines that the adsorption is successful, and the polishing head is lifted and moved above the polishing pad for polishing.

[0008] The polishing head is raised and moved above the polishing pad for polishing, including:

[0009] The main polishing operation signal is output from the process formula input terminal to the controller, and the controller controls the multi-channel electro-proportional valve to switch to the positive pressure output state.

[0010] The high-pressure gas output from the main gas source is regulated with high precision by an electric proportional valve and then flows to the various zones of the four-zone airbag and the pressurization chamber of the retaining ring.

[0011] The pressurized gas in the central area, inner ring area, outer ring area and edge area pushes the polyurethane film downward to apply differentiated surface pressure to the wafer, while maintaining the ring downward pressure to pre-compress the polishing pad around the wafer, driving the wafer to generate relative friction with the polishing pad, and performing the main polishing.

[0012] In one possible implementation, the method further includes:

[0013] Obtain the material removal rate;

[0014] The material removal rate includes:

[0015] The material removal rate is obtained using the method shown in the following formula:

[0016]

[0017] in, For the first Material removal rate of the partition, among which These correspond to the central area 4, the inner ring area 5, the outer ring area 6, and the edge area 7, respectively. It is Preston's constant. For the first The actual surface pressure exerted by the partitioned airbags on the back of the wafer. This represents the relative sliding linear velocity between the wafer and the polishing pad.

[0018] In one possible implementation, the method further includes:

[0019] The total pressure applied by the polishing head is obtained using the following formula:

[0020]

[0021] in, The total downward pressure applied by the polishing head to the polishing pad. For the corresponding number The effective force-bearing area of ​​the airbags in the partitions, To maintain the independent vertical downward pressure applied by the ring.

[0022] A second aspect of this application provides a CMP pressurization control system, the system including a pneumatic drive module, a control module, and a detection module;

[0023] The pneumatic drive module includes a main air source, a multi-channel electro-proportional valve, an exhaust valve, a polishing head, and air pipelines. The main air source outputs high-pressure clean gas. The polishing head receives the gas after pressure adjustment by the electro-proportional valve, drives the internal cavity to deform, thereby pressurizing the wafer and driving the wafer to rotate.

[0024] The internal components of the polishing head include a four-zone airbag, a polyurethane film, a retaining ring, and a shock-absorbing mounting platform.

[0025] The pneumatic drive module consists of a main air source, a multi-channel electric proportional valve, an exhaust valve, a polishing head, and air pipelines.

[0026] The control module is used to perform the method as described in any one of the first aspects.

[0027] This invention has the following advantages: The CMP pressurization control method of this invention, through the collaborative design of a four-zone airbag, an electro-proportional valve, and a controller, achieves adaptive distribution of wafer back pressure, effectively compensating for wafer warpage upon arrival without manual intervention; it steplessly adjusts the pressure of each zone according to the initial wafer morphology, and combined with the independent back pressure fine-tuning of the holding ring, it precisely pre-compresses the polishing pad, completely solving the edge effect problem of over-polishing or under-polishing; the vibration-damping mounting platform absorbs the mechanical impact under high-speed rotation, ensuring dynamic parallel contact between the wafer surface and the polishing pad, eliminating micro-scratches caused by high-frequency vibration; it is equipped with multiple safety protection mechanisms such as vacuum abnormality warning and emergency pressure cut-off lifting, ensuring high reliability; the flexible polyurethane film pressure transmission structure is uniform and easy to maintain, and the electro-proportional valve has a fast response and stable operation, adapting to the harsh operating scenarios of advanced semiconductor manufacturing processes, comprehensively solving the pain points of existing technologies. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic perspective view of the overall structure of the CMP polishing head according to an embodiment of the present invention.

[0030] Figure 2 This is a bottom view structural diagram of the four-zone airbag of the present invention.

[0031] Figure 3 This is a bottom view schematic diagram of the assembly of the polyurethane film and retaining ring according to an embodiment of the present invention.

[0032] Figure 4 This is a three-dimensional structural diagram of the retaining ring according to an embodiment of the present invention.

[0033] Figure 5 This is a cross-sectional structural diagram of the shock-absorbing mounting platform according to an embodiment of the present invention.

[0034] Figure 6 This is a three-dimensional structural diagram of the shock-absorbing mounting platform according to an embodiment of the present invention.

[0035] The labels in the diagram represent:

[0036] 1. Polyurethane film; 2. Retaining ring; 3. Four-zone airbag; 4. Central zone; 5. Inner ring zone; 6. Outer ring zone; 7. Edge zone; 8. Vibration damping mounting plate. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0039] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0040] This application provides a CMP pressurization control system, including a pneumatic drive module, a control module, and a detection module. The pneumatic drive module includes a main air source, a multi-channel electro-proportional valve, an exhaust valve, a polishing head, and air pipelines. The main air source outputs high-pressure clean gas. The polishing head receives gas pressure regulated by the electro-proportional valve, which drives the deformation of its internal cavity to pressurize and rotate the wafer.

[0041] The internal components of the polishing head include a four-zone airbag 3, a polyurethane film 1, a retaining ring 2, and a shock-absorbing mounting platform 8; the control module includes a controller, a process formula input terminal, and a device host interface. The process formula input terminal is used to switch different polishing process steps, and the device host interface is used to output process action signals. The controller is electrically connected to an electro-proportional valve; the detection module includes an inlet pressure sensor, an outlet pressure sensor, and a vacuum sensor. The pressure sensor is used to monitor the actual pressurized air pressure in each zone cavity, and the vacuum sensor is used to detect the adsorption state of the polishing head on the wafer.

[0042] Specifically, the pneumatic drive module, through the main air source, multi-channel electro-proportional valve, exhaust valve, polishing head, and air pipeline, drives the inflation and depressurization of the four-zone airbags and retaining ring, and provides safety assurance for the operation of the polishing head. The control module includes a controller, a process recipe input terminal, and a host interface. The controller outputs commands based on signals from the host interface to control the pneumatic drive module, thereby controlling the movement of the airbags inside the polishing head. Based on signals from the process recipe input terminal, the controller adjusts the magnitude of the signals sent to the pneumatic drive module, thereby regulating the downward pressure of each zone of the four-zone airbags, ensuring that the material removal rate of each zone always matches the initial morphology and process target of the incoming wafer. The detection module includes an inlet pressure sensor, an outlet pressure sensor, and a vacuum sensor. The detection module sends the detected signals to the controller, providing feedback on the system's operation, thereby monitoring and adjusting the pressure of the polishing head. This ensures the accuracy and constancy of the pressure in each radial region and edge of the wafer surface through pressure monitoring and valve group control. Combined with vacuum sensing and positive / negative pressure logic switching, it enables automatic wafer adsorption and safe demolding.

[0043] like Figure 1 and Figure 2 As shown, the four-zone airbag 3 is divided into four independent closed pressure-regulating zones from the inside out, corresponding to the central zone 4, inner ring zone 5, outer ring zone 6, and edge zone 7, respectively. The four-zone airbag of this invention receives pressurized gas from the main gas source through a multi-channel electro-proportional valve. The gas, after pressure regulation by the electro-proportional valve, is distributed to the central zone 4, inner ring zone 5, outer ring zone 6, and edge zone 7 via independent gas pipelines. The internal pressure of the airbag drives a slight elastic deformation of the flexible polyurethane film 1, uniformly transmitting the pressure to the back of the wafer. Furthermore, the controller can control the output of the multi-channel electro-proportional valve according to the dynamic switching of the process formulation, achieving dynamic stepless adjustment of the pressure in each airbag zone.

[0044] like Figure 3 , Figure 4 As shown, the bottom of the four-zone airbag 3 is provided with a polyurethane film 1, and a retaining ring 2 is provided around the periphery of the four-zone airbag 3. The polyurethane film 1 of the present invention serves as a flexible isolation and pressure transmission medium. Its upper surface is sealed to the bottom of each cavity of the four-zone airbag, and its lower surface is directly attached to the back of the wafer. Through the elasticity and flexibility of the polyurethane film, it effectively absorbs and compensates for the warpage and thickness non-uniformity of the wafer itself. The retaining ring 2 is independently set on the periphery of the four-zone airbag, and its bottom directly contacts the polishing pad. Through its independent downward pressure airbag, it receives high-precision air pressure to complete the pre-compression working position control of the polishing pad on the periphery of the wafer, thereby achieving the effect of eliminating the abrupt change in the flow field and stress concentration of the edge polishing fluid, and achieving the purpose of suppressing the edge effect.

[0045] like Figure 5 and Figure 6As shown, a shock-absorbing mounting plate 8 is provided at the connection between the upper part of the four-zone airbag 3 and the main drive shaft of the equipment. The pressurization control component of the present invention also includes a universal joint and a buffer spring assembly, which are assembled inside the shock-absorbing mounting plate 8. The shock-absorbing mounting plate 8 is rigidly connected to the main drive mechanism of the CMP equipment through the flange structure at the top. When the polishing head rotates at high speed and the polishing pad is pressed under high pressure, the surface of the polishing pad will feed back high-frequency mechanical vibration to the polishing head due to friction and micro-unevenness. The buffer mechanism and universal structure inside the shock-absorbing mounting plate 8 can effectively absorb and attenuate this mechanical vibration, so that the four-zone airbag 3 and the polyurethane film 1 can always maintain dynamic parallel contact with the rotating polishing pad under stress, which plays a safety role in preventing local rigid impact and avoiding micro-scratches on the wafer surface.

[0046] like Figures 1 to 3 As shown, the polyurethane film 1 has several micropores within the corresponding central region 4. During wafer loading, the controller switches the gas path to a negative pressure state. Through the micropores, a negative pressure suction force is rapidly established between the polyurethane film 1 and the back of the wafer, driving the polyurethane film 1 to bulge slightly upwards and firmly adsorb the wafer onto the bottom of the polishing head. When removing the film after polishing, a weak positive pressure backflushing gas is introduced into the central region 4. The gas acts on the back of the wafer through the micropores, disrupting the surface tension of the water film between the wafer and the film, thus achieving a smooth and safe wafer removal.

[0047] In the control module, the controller's input terminals are connected to the equipment host interface, process recipe input terminal, vacuum sensor, air inlet pressure sensor, and air outlet pressure sensor. The controller's output terminal is connected to a multi-channel electro-proportional valve. The equipment host interface and process recipe input terminal are used to input the start, stop, and recipe pressure signals for the CMP process steps. The vacuum sensor, air inlet pressure sensor, and air outlet pressure sensor are used to detect the internal state of the airbags and the air pressure. The vacuum sensor has two alarm functions: open circuit and no adsorption response. When the negative pressure detected during wafer adsorption does not reach the process threshold or when the negative pressure changes abruptly during movement, a pop-up alarm is triggered on the host interface to alert the driver of the adsorption abnormality. Simultaneously, a signal is output to the controller, which blocks the process operation command and stops the spindle motor to prevent the wafer from slipping out or breaking. The pressure sensor is used to monitor the actual pressure of each zone airbag and the holding ring airbag in real time. The controller, through a coupling algorithm between pressure and removal rate, can monitor the polishing status in real time and set fault warnings based on pressure deviation values ​​to determine the working condition of pneumatic components and prevent process failures caused by abnormal air pressure.

[0048] A CMP pressure control method includes controlling the air bladder inside the polishing head during wafer mounting, main wafer polishing, and wafer removal after polishing. The specific steps are as follows:

[0049] When the wafer is mounted:

[0050] S1. The device host interface outputs the wafer loading command, and the polishing head moves to the top of the wafer loading stage and falls.

[0051] S2. The controller controls the vacuum generator to start, and draws gas from the central area 4 through the gas pipeline to generate the negative pressure required for the process.

[0052] S3. Under negative pressure, the polyurethane film 1 tightly adsorbs the back side of the wafer. After the vacuum sensor detects that the negative pressure value meets the adsorption threshold, the controller determines that the adsorption is successful, and the polishing head is lifted and moved above the polishing pad.

[0053] In the control method of this invention, when the equipment performs the adsorption and loading action, a negative pressure needs to be established to grip the wafer. The vacuum generator is activated, and the oil or airflow in the central area 4 is cut off at the one-way valve. The pressure in the central area continues to decrease until the adsorption negative pressure threshold is met, and the controller determines that the wafer gripping is stable. When the polishing head carries the wafer down and adheres to the polishing pad, and enters the main polishing step, the controller controls the air path switching valve to switch to the positive pressure position. The high-pressure clean gas from the main air source is introduced into the multi-channel electro-proportional valve, and the control system enters the positive pressure pressurization mode. At this time, under the combined action of the holding ring and the partition, each area of ​​the wafer begins to undergo fine planarization polishing, and the removal rate of each area is controlled in real time by adjusting the opening size of the electro-proportional valve.

[0054] During wafer primary polishing:

[0055] T1, the process formula input terminal outputs the main polishing operation signal to the controller, and the controller controls the multi-channel electric proportional valve to switch to the positive pressure output state;

[0056] T2. The high-pressure gas output from the main gas source is regulated with high precision by the electric proportional valve and then flows to each zone of the four-zone airbag 3 and the pressurization chamber of the retaining ring 2.

[0057] The pressure gas in T3, the central area 4, the inner ring area 5, the outer ring area 6, and the edge area 7 pushes the polyurethane film 1 downward to apply differentiated surface pressure to the wafer, while the ring 2 is kept under pressure to pre-compress the polishing pad around the wafer, driving the wafer to rub against the polishing pad and starting the main polishing.

[0058] In the control method of this invention, when the wafer is executing a process step, the spindle motor starts, driving the polishing head to rotate at high speed. When the system enters the main polishing stage, high-precision vertical pressure needs to be applied to the wafer. The controller controls the electro-proportional valve to introduce air into each zone of the four-zone airbag 3. High-pressure gas flows to the four-zone airbag 3 through independent pipelines. Under the combined action of gas pressure and the elasticity of polyurethane film 1, each radial area of ​​the wafer adheres tightly to the polishing pad. At the same time, the retaining ring 2 is pressurized with independent formulation pressure, causing the retaining ring 2 to press the polishing pad to eliminate the rebound of the polishing pad at the edge of the wafer. At this time, under the independent pre-compression action of the retaining ring 2, the flow field and stress at the edge of the wafer remain stable, effectively preventing over-polishing or under-polishing of the edge.

[0059] When the wafer needs to be removed from the main polishing process, the control of the airbags switches from the operation during the main polishing to the removal operation. Specifically, the steps are from S1-S3 to T1-T3. In the control method of this invention, if the wafer is removed from the main polishing process or a stop is triggered midway, in order to smoothly peel the wafer off the polishing pad and safely unload it, the polishing head spindle stops rotating and is lifted upwards. The positive pressure in each zone of the four airbags is quickly emptied. At this time, the controller controls the introduction of a weak positive pressure backflush gas into the central zone 4. The backflush gas acts on the back side of the wafer through the micropores of the polyurethane film 1, overcoming the residual liquid tension between the wafer and the film, so that the wafer can be smoothly removed onto the washing stage. The exhaust valve group set in the air circuit helps each cavity to quickly establish backflush pressure or empty residual pressure, realizing a smooth switch between polishing pressurization and unloading removal.

[0060] In the control method of this invention, when the vacuum level suddenly drops or the gasbag pressure fluctuates abnormally due to an anomaly during the wafer polishing process, the detection sensor set in the gas path sends an abnormal signal. After the controller detects the signal, the controller stops sending process operation instructions to the main control spindle, the main spindle motor stops rotating, and at the same time the controller controls the electro-proportional valve to cut off all positive pressure inputs and triggers the polishing head to lift up in an emergency. This ensures that the polishing head will not be pressed down, whether it is during polishing or movement and an alarm is triggered, thus ensuring the safety of the equipment and devices.

[0061] In the control method of the present invention, the controller monitors the actual pressure values ​​of each zone airbag and holding ring in real time through the air inlet pressure sensor and the air outlet pressure sensor. The controller predicts and calculates the material removal rate of each corresponding area of ​​the wafer and the total downward pressure applied by the polishing head in real time according to the Preston equation and the contact mechanics model.

[0062] The formulas for calculating the material removal rate and total downward pressure are as follows:

[0063]

[0064]

[0065] in, For the first Material removal rate of the partition (of which) Corresponding to the central area 4, inner ring area 5, outer ring area 6, and edge area 7 respectively. It is Preston's constant. For the first The actual surface pressure exerted by the partitioned airbags on the back of the wafer. The relative sliding linear velocity between the wafer and the polishing pad. The total downward pressure applied by the polishing head to the polishing pad. For the corresponding number The effective force-bearing area of ​​the airbags in the partitions, To maintain the independent vertical downward pressure applied by ring 2.

[0066] The upper and lower limit alarms of the process are set by the actual pressure feedback value of each zone to judge the working stability of the pneumatic proportional valve and the main air source, and to prevent uneven wafer polishing, deterioration of non-uniformity within the wafer, or wafer breakage caused by abnormal pressure.

[0067] In the control method of this invention, the controller controls the output pressure of the multi-channel electro-proportional valve according to the switching of the initial morphology of the incoming wafer surface, thereby realizing independent, closed-loop stepless adjustment of the four-zone air pressure, as detailed below:

[0068] The initial incoming wafer detected at the process formula input terminal exhibits a "thick center, thin edge" morphology. Based on the target flatness parameters, the controller calculates the high gas pressure required to be applied to the central region 4. and the low air pressure required to be applied to edge zone 7 The computational logic must satisfy:

[0069]

[0070] When the initial incoming wafer detected by the process formula input terminal becomes "thick at the edges and thin at the center", the controller switches the pressure formula according to the target flatness parameter, increases the pressure in the edge region 7, and calculates the high gas pressure required to be applied to the edge region. The computational logic must satisfy:

[0071]

[0072] in, For the airbag pressure in the central area, and The edge region gasbag pressure under different wafer morphology states, This represents the polishing line speed.

[0073] In this way, the target control pressure of each zone of the multi-channel electro-proportional valve corresponding to different incoming wafer morphologies can be obtained, so that the material removal rate of the thicker morphology area is always slightly higher than that of the thinner morphology area, dynamically compensating for the initial morphology difference and avoiding the problem of the thin film layer being locally shaved or the residue exceeding the standard due to uneven global removal of the wafer.

[0074] In addition, when there is no signal output from the process formula, that is, when the equipment is in a static standby state, the controller will close the positive pressure proportional valve and open the air path to the exhaust valve to vent the air. The polishing head will stop pressurizing and lift up. At this time, the elastic spring group in the shock-absorbing table 8 will guide the polishing head back to the central balance position by its own mechanical restoring force, so that the system maintains the process ready state.

[0075] It has the following beneficial effects: It realizes zoned pressure control and adaptive matching of morphology: By receiving process formula and sensor morphology feedback signals through the controller, it links and regulates the dynamic stepless output of the multi-channel electro-proportional valve, so that the pressure of each zone of the four-zone airbag is precisely matched with the local removal requirements of the wafer, and completely solves the problem of difficult control of non-uniformity within the wafer in terms of global flatness.

[0076] Edge effect suppression: By combining independent back pressure control of the holding ring with multi-zone edge air pressure control, optimal pre-compression is applied to the polishing pads around the wafer throughout the main polishing process, maintaining the stability of the flow field and stress at the wafer edge and completely avoiding over-polishing or under-polishing of the edges.

[0077] Mechanical vibration absorption and micro-scratch protection: The shock-absorbing mounting table and universal mechanism work together to effectively absorb and attenuate the high-frequency impact and vibration fed back by the polishing pad under high-speed rotation and high-pressure polishing conditions, ensuring that the polishing head and polishing pad are always in a dynamic parallel fit, significantly improving the wafer surface quality and eliminating mechanical micro-scratch.

[0078] Precise response and strong safety protection: The flexible polyurethane film transmits pressure evenly and stably, the multi-channel electro-proportional valve has a fast closed-loop response and high control precision, and with the vacuum abnormality warning and emergency pressure rise mechanism, it significantly improves the production yield and equipment reliability in advanced semiconductor processing.

[0079] Numerous specific technical details are disclosed in the specification provided herein; however, those skilled in the art should understand that the practice of this invention does not absolutely depend on these specific details. To highlight the core concept of this invention, some well-known methods, structures, and techniques have not been described in detail. Furthermore, the features mentioned in different embodiments are not isolated. Without departing from the technical spirit of this invention, those skilled in the art can reasonably interweave and combine the above features according to the actual technical problem being solved. These new embodiments derived through combination also indisputably fall within the protection scope of this invention.

[0080] In summary, the embodiments listed herein are merely preferred embodiments of the present invention and are intended to explain rather than limit the invention. For those skilled in the art, any simple modifications, equivalent substitutions, or variations made to the above embodiments based on the technical essence of the present invention without departing from the spirit of the invention should be fully covered within the patent protection scope of the present invention.

Claims

1. A CMP pressurization control method, characterized in that, The method includes: The device host interface outputs the wafer loading command, and the polishing head moves to the top of the wafer loading stage and then falls. The controller controls the start-up drive module to draw gas from the central area through the gas pipeline to generate the negative pressure required for the process. Under negative pressure, the polyurethane film tightly adheres to the back side of the wafer. Once the vacuum sensor detects that the negative pressure value meets the adsorption threshold, the controller determines that the adsorption is successful, and the polishing head is lifted and moved above the polishing pad for polishing. The polishing head is raised and moved above the polishing pad for polishing, including: The main polishing operation signal is output from the process formula input terminal to the controller, and the controller controls the multi-channel electro-proportional valve to switch to the positive pressure output state. The high-pressure gas output from the main gas source is regulated with high precision by an electric proportional valve and then flows to the various zones of the four-zone airbag and the pressurization chamber of the retaining ring. The pressurized gas in the central area, inner ring area, outer ring area and edge area pushes the polyurethane film downward to apply differentiated surface pressure to the wafer, while maintaining the ring downward pressure to pre-compress the polishing pad around the wafer, driving the wafer to generate relative friction with the polishing pad, and performing the main polishing.

2. The CMP pressurization control method according to claim 1, characterized in that, The method further includes: Obtain the material removal rate; The material removal rate includes: The material removal rate is obtained using the method shown in the following formula: in, For the first Material removal rate of the partition, among which These correspond to the central area 4, the inner ring area 5, the outer ring area 6, and the edge area 7, respectively. It is Preston's constant. For the first The actual surface pressure exerted by the partitioned airbags on the back of the wafer. This represents the relative sliding linear velocity between the wafer and the polishing pad.

3. The CMP pressurization control method according to claim 2, characterized in that, The method further includes: The total pressure applied by the polishing head is obtained using the following formula: in, The total downward pressure applied by the polishing head to the polishing pad. For the corresponding number The effective force-bearing area of ​​the airbags in the partitions, To maintain the independent vertical downward pressure applied by the ring.

4. A CMP pressurization control system, characterized in that, The system includes a pneumatic drive module, a control module, and a detection module; The pneumatic drive module includes a main air source, a multi-channel electro-proportional valve, an exhaust valve, a polishing head, and air pipelines. The main air source outputs high-pressure clean gas. The polishing head receives the gas after pressure adjustment by the electro-proportional valve, drives the internal cavity to deform, thereby pressurizing the wafer and driving the wafer to rotate. The internal components of the polishing head include a four-zone airbag, a polyurethane film, a retaining ring, and a shock-absorbing mounting platform. The pneumatic drive module consists of a main air source, a multi-channel electric proportional valve, an exhaust valve, a polishing head, and air pipelines. The control module is used to perform the method as described in any one of claims 1-3.

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