Polishing device and polishing apparatus

Abstract

Provided in the present invention are a polishing device and a polishing apparatus for removing a film from the surface of a substrate. The polishing device comprises: a polishing table configured to hold and rotate the substrate; and a polishing head provided with a polishing pad for coming into contact with and being pressed against the substrate to polish the film on the surface of the substrate, the area of the polishing pad being less than or equal to the area of the substrate. The substrate is divided into at least two regions in a circumferential direction based on the thickness distribution of the film on the surface of the substrate. The at least two regions include a first region and a second region. During the process of polishing the surface of the substrate, the substrate keeps rotating, and the polishing head is configured to polish the first region at a first polishing rate and polish the second region at a second polishing rate, the first polishing rate being different from the second polishing rate. In the present application, the polishing device controls the polishing rate on the basis of the local position of the polishing head on the surface of the substrate, thereby precisely controlling the profile of the film on the entire surface of the substrate.

Description

Grinding apparatus and grinding equipment

[0001] This application claims priority to Chinese Patent Application No. 202411692115.1, filed on November 22, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This invention belongs to the field of semiconductor technology and relates to a substrate polishing apparatus and polishing equipment. Background Technology

[0003] In the manufacturing process of semiconductor components, surface planarization is becoming increasingly important. The most important technology for surface planarization is chemical mechanical polishing (CMP). CMP supplies a polishing slurry (slurry) containing abrasive particles such as silicon dioxide (SiO2) to the polishing surface of the polishing pad, and causes the substrate, which is fixed to the polishing head, to rotate synchronously with the polishing head. As a result, the substrate comes into contact with the polishing surface and slides to be polished.

[0004] A polishing head for fixing the substrate is positioned above a polishing pad. The polishing pad is larger than the substrate to be processed, allowing the substrate to be pressed onto the pad during polishing to achieve polishing of the entire substrate surface. In this polishing method, as the substrate size increases, the polishing pad size also increases, resulting in a large equipment footprint. Furthermore, the film thickness is uniform across all locations on the substrate surface, creating a uniform film thickness. However, uneven film thickness distribution often occurs on the substrate surface, resulting in uneven film contours. Even after polishing the entire substrate surface using the above method, these uneven film contours remain. Generally, the uniformity of film thickness distribution is better at the center of the substrate surface than at the edges. The unevenness is more pronounced at the circumferential edges of the substrate. Therefore, existing chemical mechanical polishing techniques struggle to precisely control the polishing of localized areas on the substrate surface, especially at the circumferential edges.

[0005] Furthermore, when grinding the edges of quadrilateral substrates, only the four vertices receive the polishing slurry, causing it to concentrate at the vertices and resulting in over-grinding of the substrate's vertices. Precise control of grinding in localized areas of the substrate surface is also difficult.

[0006] Therefore, in view of the problems existing in the prior art, the designer of this case, based on years of experience in this industry, actively researched and improved the technology, and thus the grinding device of this application was developed. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a grinding apparatus to solve the problem of poor precise control of grinding local positions on the substrate surface in the prior art.

[0008] To achieve the above and other related objectives, this application provides a polishing apparatus for removing a film from a substrate surface, comprising: a polishing table for holding and rotating the substrate; and a polishing head having a polishing pad for contacting and pressing against the substrate to polish the substrate surface film, the area of ​​the polishing pad being less than or equal to the area of ​​the substrate; wherein the substrate is divided into at least two regions in the circumferential direction according to the thickness distribution of the substrate surface film, the at least two regions including a first region and a second region; during the polishing of the substrate surface, the substrate is kept rotating, and the polishing head is configured to polish the first region at a first polishing rate and polish the second region at a second polishing rate, the first polishing rate and the second polishing rate being different.

[0009] Optionally, the same area of ​​the substrate is divided into at least two polishing zones in the radial direction according to the film thickness distribution on the substrate surface. The at least two polishing zones include a first polishing zone and a second polishing zone, and the polishing rates of the first polishing zone and the second polishing zone are different.

[0010] Optionally, the substrate further includes a central region, which is at least the area covered by the overlap between the center of the polishing pad and the center of the substrate, and the central region represents the third polishing rate.

[0011] Optionally, at least one polishing zone is divided into multiple sub-zones along the circumference of the substrate according to the film thickness distribution, and the number of sub-zones is smaller in polishing zones closer to the center of the substrate.

[0012] Optionally, the polishing apparatus includes a control unit configured to change the polishing rate by changing at least one of the polishing conditions, the polishing conditions including changing the pressure applied to the substrate surface by the polishing head, the rotational speed of the polishing head, the rotational speed of the substrate, the amount of polishing slurry supplied by the polishing head to the substrate, and the horizontal movement speed of the polishing head relative to the substrate.

[0013] Optionally, the polishing stage is further provided with a sacrificial ring surrounding the substrate, the height of the sacrificial ring relative to the substrate surface being adjustable to keep the height of the sacrificial ring relative to the substrate surface constant.

[0014] Optionally, a piezoelectric ceramic is mounted below the sacrificial ring, the piezoelectric ceramic being configured to adjust the height of the sacrificial ring to maintain a constant height of the sacrificial ring relative to the substrate surface.

[0015] Optionally, the polishing table is further provided with a polishing table base that supports the substrate. The polishing table base is raised and lowered, and the substrate is raised and lowered synchronously, so as to keep the height of the sacrificial ring relative to the surface of the substrate constant.

[0016] Optionally, the height of the sacrificial ring relative to the substrate surface is adjusted according to the desired polishing rate of the substrate edge. If the desired polishing rate of the substrate edge is greater than the desired polishing rate of the substrate center, the sacrificial ring is lower than the substrate surface. If the desired polishing rate of the substrate edge is less than the desired polishing rate of the substrate center, the sacrificial ring is higher than the substrate surface.

[0017] Optionally, the substrate is quadrilateral or circular.

[0018] Optionally, the grinding head is configured to apply a corresponding pressure to the substrate according to the film thickness of each region, wherein the film thickness is positively correlated with the pressure.

[0019] Optionally, at least one of the grinding head and the polishing table is provided with an airbag, the airbag being configured to change the downward pressure applied by the grinding head to the substrate surface by changing the magnitude of the air pressure in the airbag, the magnitude of the pressure applied by the grinding head to the substrate surface being positively correlated with the magnitude of the air pressure in the airbag.

[0020] Optionally, the grinding head further includes a grinding head base, and the airbag is installed between the grinding head base and the polishing pad.

[0021] Optionally, the polishing table includes a polishing table base, and the airbag is disposed between the substrate and the polishing table base.

[0022] Optionally, the coverage area of ​​the sacrificial ring is a range extending outward from the outer contour of the substrate by a predetermined length.

[0023] Optionally, the sacrificial ring covers at least a circular area extending at least 1 cm from the maximum dimension of the outer contour of the substrate.

[0024] Optionally, the area of ​​the polishing pad is 1 / 10 to 1 / 2 of the area of ​​the substrate.

[0025] Optionally, the polishing apparatus includes a film thickness measuring device for detecting the film thickness on the substrate surface to obtain a film thickness distribution. This application also proposes a polishing apparatus for removing a film from the surface of a quadrilateral substrate, comprising: a polishing table for holding and rotating the substrate; a polishing head having a polishing pad that contacts and presses against the substrate to polish the substrate surface film; and a control unit configured to adjust polishing conditions based on the area inside and outside the inscribed circle of the polishing head relative to the substrate to control the polishing rate inside and outside the inscribed circle, wherein a first polishing condition is applied when the polishing head is within the inscribed circle, and a second polishing condition is applied when the polishing head is outside the inscribed circle, the first polishing condition being different from the second polishing condition.

[0026] Optionally, the grinding rate is the same inside and outside the inscribed circular area.

[0027] Optionally, each polishing condition includes the pressure applied by the polishing head to the substrate surface, the rotational speed of the polishing head, the rotational speed of the substrate, the amount of polishing liquid supplied by the polishing head to the substrate, and the horizontal movement speed of the polishing head relative to the substrate, wherein at least one of the first polishing conditions is different from the second polishing condition.

[0028] Optionally, the distance between the projection point of the center of the grinding head onto the plane of the substrate and the center of the substrate, and the relative horizontal moving speed of the grinding head and the substrate, satisfy the following formula:

[0029] When 0 ≤ r ≤ b, V = V0;

[0030] When b < r < a

[0031] when hour,

[0032] Where r is the distance between the projection point of the center of the grinding head on the plane of the substrate and the center of the substrate, V0 is the preset initial speed, a is half the side length of the substrate, and b is the radius of the polishing pad on the grinding head; a circle with the center of the substrate as the center and the distance between the projection point of the center of the grinding head on the plane of the substrate and the center of the substrate as the radius intersects the edge of the substrate at multiple intersection points, and θ is the angle between the line connecting one of the intersection points to the center of the substrate and the line connecting the vertex adjacent to the intersection point to the center of the substrate.

[0033] Optionally, when the contact area between the grinding head and the substrate is a transition area located both inside and outside the inscribed circle area, the control unit is further configured to obtain a ratio coefficient of the first grinding condition and the second grinding condition based on the ratio of the area of ​​the polishing pad inside and outside the inscribed circle area to the total area of ​​the polishing pad, obtain the grinding condition of the transition area by combining the first grinding condition and the second grinding condition with different ratio coefficients, and adjust the grinding rate according to the obtained grinding condition of the transition area.

[0034] Optionally, the polishing table is further provided with a polishing pad trimmer that rotates synchronously with the substrate. The polishing pad trimmer is located in the non-substrate area between the inscribed circle and the circumscribed circle of the quadrilateral substrate. When the polishing pad grinds the area outside the inscribed circle of the substrate, the polishing pad simultaneously contacts the substrate and the polishing pad trimmer to trim the polishing pad while grinding the substrate.

[0035] Optionally, the polishing pad trimmer is configured to move up and down between a waiting position and a trimming position. When the polishing pad is outside the tangential circle region of the polishing pad grinding substrate, if the polishing pad needs trimming, the polishing pad trimmer moves to the trimming position; if the polishing pad does not need trimming, the polishing pad trimmer moves to the waiting position.

[0036] Optionally, the substrate has a plurality of specific regions in the circumferential and / or radial directions of the substrate, which are obtained according to the film thickness distribution on the substrate surface. During the grinding of the substrate surface, the substrate is kept rotating, and the grinding head is configured with a grinding rate according to the film thickness of each specific region, wherein the film thickness is positively correlated with the grinding rate.

[0037] Optionally, the system also includes a conveyor, wherein there are multiple polishing stages, the conveyor rotating to engage the substrate and transfer the engaged substrate between the multiple polishing stages.

[0038] Optionally, the grinding head includes at least a first grinding head for removing a first film material from the surface of the substrate and a second grinding head for removing a second film material from the surface of the substrate. The plurality of polishing tables includes at least a second polishing table and a third polishing table. The conveying member is configured to transfer the substrate with the first film material removed from the surface of the substrate from the second polishing table to the third polishing table after the first grinding head removes the first film material from the surface of the substrate, so that the substrate on the third polishing table has the second film material removed by the second grinding head.

[0039] Optionally, the plurality of polishing tables further includes a first polishing table and a fourth polishing table for loading and unloading the substrate, respectively. The transfer member is configured to transfer the substrate with the second film material removed from the surface of the substrate from the third polishing table to the fourth polishing table after the second grinding head removes the second film material, so that the substrate is unloaded from the fourth polishing table. The plurality of polishing tables are evenly distributed in the same circumferential direction.

[0040] Optionally, the plurality of polishing tables further includes a fifth polishing table for loading and unloading shared materials. The conveyor is configured to transfer the substrate with the second film material removed from the surface of the substrate from the third polishing table to the fifth polishing table after the second grinding head removes the second film material, so that the substrate is unloaded from the fifth polishing table. The plurality of polishing tables are evenly distributed in the same circumferential direction.

[0041] Optionally, the grinding apparatus further includes a cleaning mechanism for cleaning the substrate surface after each film removal.

[0042] Optionally, the number of grinding heads is at least two, and each grinding head is used to remove different film materials from the substrate surface.

[0043] Optionally, the polishing table is placed horizontally with the grinding head or at an angle relative to the horizontal plane.

[0044] Optionally, the grinding head is disposed above the substrate.

[0045] Optionally, the grinding head is disposed below the substrate.

[0046] This application also proposes a polishing apparatus, including an electrochemical polishing device and any of the polishing devices described above, wherein the polishing device is configured to perform CMP treatment on the substrate after the substrate is subjected to SFP treatment by the electrochemical polishing device.

[0047] As described above, the grinding apparatus in this application controls the grinding rate based on the local position of the grinding head on the substrate surface, thereby achieving precise control of the film contour across the entire substrate surface.

[0048] Overview of the attached figures

[0049] The features and performance of the present invention are further described by the following embodiments and accompanying drawings.

[0050] Figure 1 is a schematic diagram of the structure of a grinding device in one embodiment of this application.

[0051] Figure 2 is a schematic diagram of the grinding device provided with at least one grinding head in this application.

[0052] Figure 3 is a schematic diagram of the grinding device with an airbag in the grinding head and polishing table in this application.

[0053] Figure 4 is a partial schematic diagram of the circumferential division of the substrate in this application.

[0054] Figure 5 is a schematic diagram showing the division of the polishing area in the radial direction of the substrate in Figure 4.

[0055] Figure 6(a) is a top view of the grinding device with piezoelectric ceramics in one embodiment of the present application; Figure 6(b) is a side view of the grinding device with piezoelectric ceramics in one embodiment of the present application.

[0056] Figure 7 is a schematic diagram of a grinding device with four stations in one embodiment of this application.

[0057] Figure 8 is a schematic diagram of the grinding device with three stations in another embodiment of this application.

[0058] Figure 9 is a partial structural schematic diagram of a grinding device grinding a square substrate in one embodiment of this application.

[0059] Preferred embodiments of the present invention

[0060] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0061] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0062] For ease of description, spatial relation terms such as “below,” “under,” “lower,” “below,” “below,” “above,” “upper,” and “above” may be used herein to describe the relationship between an element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for devices in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0063] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0064] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0065] Figure 1 shows a top view of the overall configuration of a polishing apparatus in one embodiment. The polishing apparatus shown in Figure 1 performs a series of polishing processes, including polishing the substrate surface and cleaning the polished substrate. The polishing apparatus includes substrate cassettes LP1-LP3 for loading substrates, a front-end robot 101, a front-end cavity 102, a process robot 103, and multiple process cavities PM11, PM12, PM13, PM14, PM21, PM22, PM23, PM24, PM31, PM32, PM33, and PM34. The multiple process cavities include electrochemical polishing cavities PM21-PM24 for performing stress-free polishing (SFP), chemical mechanical polishing cavities PM31-PM34 for performing chemical mechanical polishing (CMP), and cleaning cavities PM11-PM14 for cleaning the substrate. The front-end robot 101 removes the substrate from the substrate cassettes LP1-LP3 and transfers the substrate to the process robot 103. The process robot 103 first transfers the substrate to the electrochemical polishing chambers PM21-PM24 for SFP processing, then to the cleaning chambers PM11-PM14 to clean the SFP-processed substrate, followed by the chemical mechanical polishing chambers PM31-PM34 for CMP processing, and then back to the cleaning chambers PM11-PM14 for further cleaning. After the substrate processing is complete, the process robot 103 removes the processed substrate from the process chambers and transfers it to the front-end robot 101. The front-end robot 101 retrieves the substrate and transfers it to the substrate cassettes LP1-LP3. It should be understood that other numbers of process chambers can be set to perform cleaning, SFP, and CMP processes on the substrate, and this application does not limit this. Each of the electrochemical polishing chambers PM21-PM24 is equipped with an electrochemical polishing device to perform SFP processing on the substrate. It should be noted that the polishing device in this application can achieve directional polishing and is applicable to the polishing processes of copper interconnects in damascus steel processes and some thin-wire substrate surface films.

[0066] As shown in Figure 1, the polishing apparatus of this embodiment includes a film thickness measuring device 200 for detecting the film thickness profile of the substrate surface (polished surface). The type of film thickness measuring device 200 is not limited, as long as it can obtain the film thickness profile of the substrate. For example, the film thickness measuring device 200 may be a non-contact measuring machine such as an eddy current type or an optical type, or it may be a measuring machine that detects the film thickness profile by scanning a detection head above the substrate non-contactly. Alternatively, the film thickness measuring device 200 may be a measuring machine that scans a probe in contact with the substrate surface and detects the surface unevenness distribution of the substrate by monitoring the up-and-down movement of the probe. In either contact or non-contact detection methods, the output of the detection is the film thickness or a signal equivalent to the film thickness.

[0067] A film thickness measuring device measures the film thickness distribution on the substrate surface, and the polishing equipment performs CMP on the substrate based on the film thickness distribution measured by the film thickness measuring device. The polishing apparatus provided by this invention can solve the problem of unevenness on the entire surface of the substrate while polishing, but this polishing method requires a longer time to complete compared with traditional large polishing heads. Therefore, the substrate can first be subjected to SFP process. According to the total amount of polishing to be removed from the substrate, the entire surface of the substrate is subjected to SFP process to achieve uniform thickness removal. SFP achieves 80% to 90% of the total film thickness removal on the substrate surface, completing the rough polishing of most of the film thickness removal on the substrate surface; then, the substrate is subjected to CMP process using the chemical mechanical polishing chamber provided by this invention to achieve fine polishing of the remaining film thickness on the substrate surface according to the film thickness distribution on the substrate surface. In some embodiments, SFP achieves 80% to 90% of the total film thickness removal on the substrate surface, and CMP achieves 10% to 20% of the total film thickness removal on the substrate surface. In other specific embodiments, rough polishing can also be achieved using other polishing processes, such as a CMP device with a large polishing head, as long as it can achieve uniform film thickness removal on the substrate.

[0068] The polishing equipment achieves different polishing amounts by controlling the polishing rate. In some embodiments, as shown in FIG1, the film thickness measuring device 200 in the polishing equipment can be designed to be located outside the process chamber, and there is at least one such device. After measuring the film thickness on the substrate surface outside the process chamber, the polishing amount is determined and then transmitted to the process chamber for CMP. Alternatively, a film thickness measuring device can be designed in each chemical mechanical polishing chamber and each electrochemical polishing chamber to detect the film thickness of the substrate in real time, determine the polishing amount, and then perform CMP on the substrate. It should be noted that the film thickness in this application refers to the vertical thickness of the film material on the substrate surface.

[0069] Figure 2 is a schematic diagram showing the polishing apparatus for performing CMP on the substrate in the chemical mechanical polishing chambers PM31 to PM34 shown in Figure 1. Since the polishing apparatuses in the chemical mechanical polishing chambers PM31 to PM34 have the same structure, only one polishing apparatus will be described below.

[0070] Referring to Figures 2 and 3, the polishing apparatus includes a polishing table 3 that holds and rotates the substrate W, and a polishing head 2 located above the polishing table 3. Referring to Figure 3, the polishing head 2 is equipped with a polishing pad 21 facing the substrate surface (the surface to be polished), and the area of ​​the polishing pad 21 is less than or equal to the substrate area. In some embodiments, the area of ​​the polishing pad is 1 / 10 to 1 / 2 of the substrate area. The polishing table and the polishing head are placed horizontally at the same time, or they can be placed at a certain angle relative to the horizontal plane. In addition, the polishing head can be disposed above or below the substrate W, and this application does not limit this.

[0071] The polishing slurry is supplied to the central conduit 22 extending along the axial direction of the polishing head 2, and then flows from the central conduit 22 to the center of the polishing pad 21, and then from the center of the polishing pad 21 to the edge of the polishing pad, so that the polishing slurry forms a complete liquid film between the polishing pad 21 and the substrate during CMP, which corrodes and impacts the substrate surface material.

[0072] Referring to Figure 2, during the polishing process, the polishing head 2 rotates along the central axis indicated by Z2 to polish the substrate surface with the polishing pad 21 (see Figure 3). The polishing table 3 carries the substrate W and rotates around the central axis indicated by Z1. The polishing head 2 also selectively moves along the direction indicated by X according to different polishing paths of the polishing pad 21 on the substrate surface, causing the polishing pad 21 to translate on the substrate W surface. It should be noted that in this application, the polishing path refers to the movement path of the polishing pad's center when the polishing head translates on the substrate surface. For example, as shown in Figure 5, when the polishing path of the polishing pad 21 on the polishing head 2 coincides with or partially coincides with circumference A centered on the substrate center Z1, the polishing pad 21 on the polishing head 2 does not translate on the substrate surface. When the polishing path of the polishing pad 21 on the polishing head 2 moves from a certain position on circumference A to a certain position on another circumference B on the substrate surface (or conversely, from circumference B to circumference A, the direction of translation of the polishing pad 21 on the substrate surface is not limited), the polishing pad 21 on the polishing head 2 translates along the substrate surface from circumference A to circumference B.

[0073] The polishing head 2 polishes the substrate surface at different polishing rates based on the varying film thickness distribution at different locations on the substrate surface. The polishing rate is positively correlated with the film thickness; that is, the thicker the film on the substrate surface, the faster the polishing head 2 polishes the substrate surface. In areas with thicker film on the substrate surface, increasing the polishing rate can shorten the polishing time and improve polishing efficiency; while in areas with thinner film on the substrate surface, the polishing rate needs to be reduced to prevent over-polishing. The polishing rate can be changed by altering one or more of the following polishing conditions: the pressure applied by the polishing head to the substrate surface, the rotational speed of the polishing head, the rotational speed of the substrate, and the amount of polishing slurry supplied by the polishing head to the substrate. The control unit of the polishing apparatus changes the polishing rate by controlling one or more of these factors. For example, the greater the pressure applied by the polishing head to the substrate surface, the faster the polishing rate; the faster the rotational speed of the polishing head, the faster the polishing rate; the faster the rotational speed of the substrate, the faster the polishing rate; and the more polishing slurry supplied by the polishing head to the substrate, the faster the polishing rate. The following example illustrates how applying different pressures to the substrate surface based on varying film thicknesses changes the polishing rate. Polishing head 2 applies different pressures to the substrate based on its film thickness to achieve different polishing rates and thus planarize the substrate surface. Specifically, the target polishing amount at different locations on the substrate W is determined based on the film thickness at those locations. Based on these target polishing amounts, polishing head 2 applies different pressures to achieve different polishing rates and planarize the substrate surface. It's conceivable that the target polishing amount is the difference between the film thickness measured by the film thickness measuring device and the target film thickness of the substrate, and that planarization of the substrate surface means that the target film thickness is the same at different locations. The design of the pressure applied to the substrate is not limited; the pressure applied by polishing head 2 on the substrate surface can be adjusted. For example, in Figure 2, the lifting position of polishing head 2 can be adjusted via lifting mechanism 13 coupled to polishing head 2 to regulate the pressure applied by polishing head 2 on the substrate surface. After the polishing pad 21 on polishing head 2 contacts the substrate, the greater the descent distance of polishing head 2, the greater the pressure applied by polishing head 2 on the substrate surface. A lifting mechanism 13 is mounted on a support frame 1. The support frame 1 includes a crossbeam 12 and columns 11 supporting both ends of the crossbeam 12. The lifting mechanism 13 connects the crossbeam 12 and the columns 11, and drives the crossbeam 12 to rise and fall relative to the columns 11, thereby raising and lowering the grinding head 2. Furthermore, different pressures applied by the grinding head 2 to the substrate can be achieved by incorporating airbags in at least one of the grinding head 2 and the polishing table 3, and by controlling the air pressure within the airbags to alter the pressure applied by the grinding head 2 to the substrate surface. The pressure applied by the grinding head 2 to the substrate surface is positively correlated with the air pressure within the airbags. Therefore, the higher the air pressure within the airbags, the greater the pressure applied by the grinding head 2 to the substrate surface; conversely, the lower the air pressure within the airbags, the less pressure applied by the grinding head 2 to the substrate surface.As shown in the embodiment of FIG3, the polishing table 3 includes a polishing table base 31, and an airbag 6 is provided between the substrate W and the polishing table base 31. The grinding head 2 includes a grinding head base 24, and an airbag 6 is provided between the grinding head base 24 and the polishing pad 21. The pressure applied by the grinding head 2 to the substrate W is changed by changing the air pressure of at least one of the two airbags 6. Specifically, the air supply unit 7 supplies gas to the airbag 6. The air supply unit 7 includes an air supply pipe 72 connected to the airbag 6 and supplying gas to the airbag 6, and an air pressure regulating valve 71 located in the air supply pipe 72 and used to control the pressure in the airbag 6. In the exemplary embodiment of FIG3, one airbag is provided for both the grinding head 2 and the polishing table 3. When it is necessary to change the pressure applied by the grinding head 2 to the substrate, the pressure applied by the grinding head 2 to the substrate can be changed by changing the air pressure of one of the two airbags 6, or by changing the air pressure in both airbags 6. It should be understood that in the embodiment shown in Figure 3, both the polishing table 3 and the grinding head 2 are equipped with airbags 6. In other embodiments, airbags 6 can be provided in either the grinding head 2 or the polishing table 3. It should be noted that since the overall thickness of the film material removed from the substrate surface is relatively thin, the change in pressure applied to the substrate surface is small. Changing the downward pressure applied by the grinding head by altering the air pressure in the airbag is more precise than controlling the grinding head's movement via a lifting mechanism. Therefore, using airbags in the polishing apparatus to change the pressure applied by the grinding head to the substrate surface is superior. It should be understood that the grinding head 2 has an air passage 23 penetrating the grinding head base 24. The air passage 23 connects the air supply unit 7 and the airbag 6, allowing the air supply unit 7 to supply gas to the airbag 6 in the grinding head 2. The central conduit 22 through which the polishing fluid flows and the air passage 23 are two independent channels. Similar to the grinding head 2, the polishing table 3 also has an air passage (not shown) penetrating the polishing table base 31 to supply gas from the air supply unit 7 to the airbag 6 of the polishing table.

[0074] To achieve substrate surface planarization, the substrate surface is polished at a specific polishing rate in a specific region of the substrate. This specific region is defined by the controller 100 according to the film thickness distribution on the substrate surface in the circumferential and / or radial directions. In some embodiments, the substrate surface is divided into multiple regions in the circumferential direction according to the film thickness distribution, with regions having film thicknesses within the same range grouped within the same region, so that the substrate surface film material is removed at the same polishing rate within the same region. The size of the film thickness range needs to be determined based on the polishing precision; the higher the polishing precision, the smaller the difference in film thickness ranges. During polishing, the substrate is rotated, and the polishing pad is first positioned in a first region, the position of which is determined by the film thickness distribution in the circumferential direction of the substrate. In the first region, the polishing head polishes the substrate surface at a first polishing rate. Then, the polishing head moves from the first region to a second region and polishes the substrate surface at a second polishing rate. Similarly, the position of the second region is also determined by the film thickness distribution in the circumferential direction of the substrate, and the first and second regions on the substrate have different film thickness ranges. Circumferential polishing can solve the problem of uneven circumferential film distribution on the substrate surface in the prior art, especially the problem of uneven circumferential film distribution at the substrate edge after the previous SFP process. Furthermore, to further improve the polishing accuracy of the substrate, in some embodiments, each region obtained in the above embodiments is further divided radially to obtain multiple polishing intervals. The position of each polishing interval on the substrate surface radially is determined according to the film thickness distribution. In the embodiment shown in Figure 4, the substrate is divided into regions C1 and C2 in the circumferential direction according to the film thickness distribution on the substrate surface. Since the film thickness ranges of C1 and C2 are different, the polishing head polishes them at different rates. It should be noted that other regions divided in the circumferential direction of the substrate are not shown. To further improve the polishing accuracy of the substrate, each region is further divided into at least two polishing intervals at different radii on the substrate. As shown in Figure 5, only the radial division of region C2 is explained. Region C2 is divided into different polishing intervals C21, C22, and C23 in the radial direction according to the film thickness distribution. The polishing head polishes C21 and C22 at different rates, and C22 and C23 at different rates. In other embodiments, the film thickness uniformity is better closer to the center of the substrate. To further improve the polishing accuracy, at least one polishing interval is divided into multiple sub-intervals along the circumferential direction of the substrate. The number of sub-intervals is smaller closer to the center of the substrate. Some polishing intervals have good uniformity and can be left undivided. In addition, the central region of the substrate has good uniformity and can be left undivided, instead being treated as a whole. The polishing rate of the central region is a constant third polishing rate. This central region is at least the area where the center of the polishing pad overlaps with the center of the substrate.It should be understood that a specific region can be obtained by dividing the substrate circumferentially in the above embodiments, or by dividing it both circumferentially and radially, or by dividing it only in the radial direction of the substrate. In this embodiment, the substrate is circular or quadrilateral, and more specifically, the quadrilateral is square or rectangular.

[0075] The grinding rate in a specific area is adjusted by changing different grinding conditions, including the pressure applied by the grinding head to the substrate surface, the rotational speed of the grinding head, the rotational speed of the substrate, the amount of polishing slurry supplied by the grinding head to the substrate, and the horizontal movement speed of the grinding head relative to the substrate. The grinding rate of the grinding head on the specific area is changed by changing at least one of the grinding conditions.

[0076] During CMP processing of substrate edges, the flatness of the substrate edges is often worse than that of the substrate center, a phenomenon known as edge collapse. Therefore, as shown in Figures 6(a) and 6(b), in some embodiments, a sacrificial ring 4 is provided around the substrate periphery, allowing the substrate edges and sacrificial ring 4 to be ground simultaneously, preventing over-grinding of the substrate edges and edge collapse. To stably control the grinding effect, the entire surface of the polishing pad (grinding surface) needs to be fully in contact when grinding the substrate edges. Therefore, the sacrificial ring 4 needs to extend a predetermined length from the outer contour of the substrate, covering at least a circular area extending at least 1 cm from the maximum dimension of the substrate contour. As shown in Figure 6(a), the maximum dimension of the substrate contour is the diagonal contour, and the sacrificial ring 4 needs to cover a circular area extending at least 1 cm from the diagonal contour of the substrate. Furthermore, this application does not limit the shape of the outer contour of the sacrificial ring; it can be a circle as shown in Figure 6(a) or other shapes. The material of the sacrificial ring can be the same as the film material being ground on the substrate surface to better control the grinding rate of the substrate edges. For example, when the film material is copper, the material of the sacrificial ring can also be copper. In other embodiments, the sacrificial ring can be made of a metal or metal alloy that is harder than the film material, such as titanium, tantalum, or an alloy.

[0077] The surface of the sacrificial ring is worn down as the substrate edge is ground. To ensure that the height difference between the upper surface of the sacrificial ring and the substrate surface remains constant, the height between the sacrificial ring and the substrate surface is designed to be adjustable. In some embodiments, as shown in FIG6(b), the grinding apparatus includes a polishing table 3, which includes a rotatable polishing table base 31. The polishing table base 31 rotatably supports the substrate W, wherein a rotation drive assembly 32 coupled to the polishing table base 31 provides rotational power for the rotation of the polishing table base 31. A sacrificial ring 4 is disposed around the outer periphery of the substrate W, and a piezoelectric ceramic 5 is disposed below the sacrificial ring 4. By changing the voltage applied to the piezoelectric ceramic 5, the piezoelectric ceramic is deformed, causing the sacrificial ring 4 to rise or fall, thereby keeping the height of the sacrificial ring 4 relative to the substrate surface constant. It should be understood that the position of the substrate W can also be adjusted by the lifting drive assembly (not shown) to change the height of the sacrificial ring 4 relative to the substrate surface. Furthermore, the height of the sacrificial ring relative to the substrate surface (the surface being polished) is adjustable, which is also beneficial for adjusting the height difference between the sacrificial ring and the substrate surface according to the desired polishing rate of the polishing head on the substrate edge. If the desired polishing rate of the substrate edge is greater than the polishing rate of the middle of the substrate, the sacrificial ring is lower than the substrate surface; if the desired polishing rate of the substrate edge is greater than the desired polishing rate of the middle of the substrate, the sacrificial ring is higher than the substrate surface.

[0078] The polishing table is also equipped with a polishing pad trimmer that rotates synchronously with the substrate. When the substrate is square, as shown in Figure 6(b), the polishing pad trimmer 9 is located in the non-substrate area between the inscribed circle and the circumscribed circle of the quadrilateral substrate W. When the polishing pad is grinding outside the inscribed circle area of ​​the substrate, the polishing pad can simultaneously contact the substrate W and the polishing pad trimmer 9 to trim the polishing pad while grinding the substrate W, thereby accelerating the polishing efficiency of the substrate. The polishing pad trimmer is configured to move up and down between a waiting position and a trimming position. When the polishing pad is grinding outside the inscribed circle area of ​​the substrate, if the polishing pad needs trimming, the polishing pad trimmer 9 moves to the trimming position; when the polishing pad does not need trimming, the polishing pad moves to the waiting position.

[0079] The number of polishing tables is at least one, and the number of polishing tables can be designed according to needs. As shown in the embodiment of Figure 6(a), there is one polishing table 3, while in other embodiments, multiple stations can be designed, with one polishing table in each station. The movement of each polishing table can be individually controlled. As shown in Figure 7, each rotary drive assembly 32a and 32b drives its respective polishing table to rotate, carrying its respective substrate W to rotate independently. In some embodiments, as shown in Figure 7, the polishing apparatus has four stations: a substrate loading / unloading area, a first film material removal area, and a second film material removal area. Each station has one polishing table 3. The first polishing table 301 is located in the substrate loading / unloading area, the second polishing table 302 is located in the first film material removal area, the third polishing table 303 is located in the second film material removal area, and the fourth polishing table 304 is located in the substrate unloading area. The substrate W is transferred from outside the process cavity to the first polishing stage 301 in the substrate loading and unloading area inside the process cavity. On the second polishing stage 302 in the first film material removal area, the first film material is removed by the first grinding head 2a (as shown in Figure 2a). On the third polishing stage 303 in the second film material removal area, the second film material is removed by the second grinding head 2b (as shown in Figure 2b). Finally, the substrate is unloaded on the fourth polishing stage 304 in the substrate unloading area, thus transferring the substrate from inside the process cavity to outside. The polishing apparatus also includes a conveyor 8, which is driven by a rotary drive assembly (not shown) to rotate around the central axis Z3 to engage the substrate W and transfer it between multiple polishing stages 301-304. For example, it is sequentially transferred from the first polishing stage 301 to the second polishing stage 302, the third polishing stage 303, and the fourth polishing stage 304, and finally transferred to the fourth polishing stage 304 to await the process robot outside the process cavity to transfer the substrate W from the fourth polishing stage 304 to outside the process cavity. In other embodiments, the polishing apparatus can also be designed with three stations, where loading and unloading of the substrate are completed in the same station, with a single polishing table shared for both. As shown in the embodiment in Figure 8, the polishing apparatus includes a loading area and, similar to the embodiments described above, a first film material removal area and a second film material removal area. A fifth polishing table 305 is located in the substrate unloading area. The substrate is transferred from outside the process chamber to the fifth polishing table 305 in the substrate loading area. After removing the first film material in the first film material area and the second film material in the second film material removal area, the substrate is transferred to the fifth polishing table 305 to await removal from the process chamber by a process robot outside the process chamber. Both the first and second polishing heads can be controlled independently; for example, the movement of each polishing head, the type and flow rate of the polishing fluid introduced into the polishing head can be controlled independently, ensuring that the movement and operating modes of the two polishing heads do not interfere with each other. Here, to remove different film materials from the substrate surface, two polishing heads are designed to remove different film materials respectively. Each polishing head is supplied with a corresponding type of polishing fluid according to the film material being removed, and its polishing conditions are adjusted according to the polishing requirements.It should be understood that, in order to increase the types of film materials removed, a corresponding number of grinding heads and a corresponding number of stations can be added to ensure that the removal of each type of film material on the substrate surface is completed in its respective station by its respective grinding head. In another embodiment, there is one and only one station in the process chamber, and the loading and unloading of the substrate, film material removal, etc. can all be completed in the same station, as shown in Figure 2, where the two types of film materials on the substrate surface are removed by the first grinding head 2a and the second grinding head 2b, respectively.

[0080] In addition, a substrate cleaning process is required between the two film material removal processes on the substrate surface. This process can be completed in a chemical mechanical polishing (CMP) chamber, where a cleaning nozzle is added to spray cleaning fluid onto the substrate surface to clean the substrate; or it can be completed in a separate cleaning chamber set outside the CMP chamber.

[0081] The polishing apparatus also includes a controller 100, which controls the operation of all functional components of the polishing apparatus (polishing table, polishing head, sacrificial ring, polishing pad dresser, conveyor and other structural components, motors, electric cylinders, air cylinders and other power units for movement, polishing slurry supply unit for starting and stopping, and gas supply unit for starting and stopping). In some embodiments, the controller 100 further divides the substrate surface into specific areas according to the film thickness distribution on the substrate surface, and the controller 100 further adjusts the polishing conditions according to the different positions of the polishing head relative to the substrate to control the polishing rate.

[0082] During the polishing process of a quadrilateral substrate, the substrate is rotated, polishing slurry is sprayed onto the substrate surface, and the polishing head is pressed against the substrate surface while moving horizontally and rotating to remove the surface film. However, when polishing the substrate edges, only the four apex corners of the substrate receive the polishing slurry, causing the polishing head to over-polish the apex corners. In this application, the polishing conditions are changed according to the horizontal movement position of the polishing head relative to the substrate surface to control the polishing rate.

[0083] The polishing head is configured with different polishing conditions inside and outside the inscribed circle region of the quadrilateral substrate to more stably control the polishing rate. The polishing conditions are similar to those in the above embodiments, including the pressure applied by the polishing head to the substrate surface, the rotational speed of the polishing head, the rotational speed of the substrate, the amount of polishing slurry supplied by the polishing head to the substrate, and the horizontal movement speed of the polishing head relative to the substrate. The controller 100 controls the polishing rate of the inner and outer surfaces of the substrate within the inscribed circle region by changing at least one of the polishing conditions.

[0084] If the film material removed outside the inscribed circle region of the substrate is the same as the film material removed within the inscribed circle region of the substrate, then the grinding rate outside the inscribed circle region of the substrate is the same as the grinding rate within the inscribed circle region of the substrate; otherwise, the grinding rate outside the inscribed circle region of the substrate is different from the grinding rate within the inscribed circle region of the substrate.

[0085] During the substrate polishing process, the controller adjusts the polishing conditions based on the horizontal movement position of the polishing head on the substrate surface to control the polishing rate. There are no restrictions on how the polishing conditions are adjusted.

[0086] In some embodiments, the polishing conditions are adjusted according to the horizontal movement position of the polishing head on the substrate surface to control the polishing rate of the substrate. If the polishing head is within the inscribed circle region of the substrate, the polishing conditions are adjusted according to the desired polishing rate to obtain the first polishing condition; if the polishing head is outside the inscribed circle region of the substrate, the polishing conditions are adjusted according to the desired polishing rate to obtain the second polishing condition. Normally, the desired polishing rate is the same inside and outside the inscribed circle region of the substrate. However, since the area outside the inscribed circle region of a quadrilateral substrate only includes the four corners of the substrate, the polishing pad will not always be in contact with the substrate. Therefore, different polishing conditions, namely the first polishing condition and the second polishing condition, are required to ensure that the final polishing rate obtained across the entire substrate surface is the same. However, in some cases, the desired polishing rate at the edge of the substrate differs from that at the center of the substrate. Therefore, different polishing conditions, namely the first polishing condition and the second polishing condition, are required to be set according to the desired polishing rates at the edge and center respectively, resulting in different final polishing rates across the entire substrate surface. The difference between the first and second polishing conditions can be achieved by changing at least one parameter of the aforementioned polishing conditions, i.e., at least one of the first polishing conditions is different from the second polishing condition. However, sometimes the contact area between the grinding head and the substrate is partly located within the inscribed circle area and partly located in the transition area outside the inscribed circle area. The ratio coefficient of the first grinding condition and the second grinding condition is obtained based on the area ratio of the polishing pad inside and outside the inscribed circle area. The grinding conditions of the transition area are obtained by combining the first grinding condition and the second grinding condition with different ratio coefficients.

[0087] In other embodiments, the grinding rate of the substrate at different horizontal moving positions is controlled by adjusting the horizontal moving speed of the grinding head on the substrate surface. Based on the distance between the projection point of the center of the grinding head 2 on the plane of the substrate W and the center of the substrate W, the horizontal moving speed of the grinding head 2 is adjusted. When the projection point of the center of the grinding head 2 on the plane of the substrate W is located in the region between the inscribed circle region and the circumscribed circle region of the substrate W, the horizontal moving speed of the grinding head 2 is increased, and the dwell time of the grinding head 2 at the apex corner of the substrate W is reduced, thereby controlling the removal rate of the film material at the apex corner of the substrate W. The distance r between the projection point of the center of the grinding head 2 on the plane of the substrate W and the center of the substrate W is obtained by the horizontal moving position of the grinding head 2, and the horizontal moving speed V of the grinding head 2 is controlled according to the following formula:

[0088] When 0 ≤ r ≤ b, V = V0;

[0089] When b < r < a

[0090] when hour,

[0091] Where V0 is the preset initial velocity, a is half the side length of substrate W, and b is the radius of polishing pad 21. As shown in Figure 9, a circle C1 is formed with the center Z1 of substrate W as the center and the distance between the projection point of the center of polishing head 2 on the plane of substrate W and the center Z1 of substrate W as the radius. The edge of substrate W intersects with circle C1. For each vertices of substrate W, the line connecting one of the intersection points to the center of substrate W is L1, and the line connecting the vertex of the vertices to the center of substrate W is L2. The angle between L1 and L2 is θ. During the horizontal movement of substrate W, θ can be calculated based on half the side length a of substrate W and the distance r between the projection point of the center of polishing head 2 on the plane of substrate W and the center of substrate W.

[0092] When 0 ≤ r ≤ b, as the substrate W rotates, the contact area between the polishing pad 21 of the polishing head 2 and the substrate W can always cover a circular area with a radius of r from the center of the substrate, resulting in a more concentrated polishing effect. However, when b < r ≤ a, as the substrate W rotates, the movement trajectory of the polishing head 2 on the substrate W forms a ring or spiral shape. Therefore, it is necessary to reduce the horizontal moving speed of the polishing head 2 relative to the substrate W and increase the dwell time of the polishing head 2 on the substrate W. At this time, only the apex corner of substrate W receives the polishing slurry. To prevent the polishing slurry from accumulating in the corner area, it is necessary to increase the horizontal moving speed of the polishing head 2 and reduce the dwell time of the polishing head 2 at the apex corner of the substrate. It should be understood that when Simultaneously, while increasing the horizontal movement speed of the polishing head 2, the rotational speed of the substrate W can also be increased, reducing the dwell time of the polishing head at the apex of the substrate and better controlling the polishing rate at the apex of the substrate. It should be understood that driving the polishing head is for driving the movement of the polishing pad on the substrate surface; therefore, the horizontal movement of the polishing head on the substrate surface is synchronized with the polishing pad. In this application, the polishing apparatus maintains substrate rotation during the polishing process and controls the polishing rate according to the different positions of the polishing head on the substrate surface, achieving precise control of the film contour across the entire substrate surface.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A grinding apparatus for removing a film from the surface of a substrate, characterized in that, include: A polishing table for holding and rotating the substrate; The grinding head is provided with a polishing pad for contacting and pressing against the substrate to grind the surface film of the substrate, wherein the area of ​​the polishing pad is less than or equal to the area of ​​the substrate; The substrate is divided into at least two regions in the circumferential direction according to the film thickness distribution on the substrate surface. The at least two regions include a first region and a second region. During the grinding process of the substrate surface, the substrate is rotated. The grinding head is configured to grind the first region at a first grinding rate and grind the second region at a second grinding rate. The first grinding rate and the second grinding rate are different.

2. The grinding apparatus according to claim 1, characterized in that, The same area of ​​the substrate is divided into at least two polishing zones in the radial direction according to the film thickness distribution on the substrate surface. The at least two polishing zones include a first polishing zone and a second polishing zone, and the polishing rates of the first polishing zone and the second polishing zone are different.

3. The grinding apparatus according to claim 1, characterized in that, The substrate further includes a central region, which is at least the area covered by the overlap between the center of the polishing pad and the center of the substrate, and the central region represents the third polishing rate.

4. The grinding apparatus according to claim 3, characterized in that, At least one grinding zone is divided into multiple sub-zones along the circumference of the substrate according to the film thickness distribution, and the number of sub-zones is less in the grinding zone closer to the center of the substrate.

5. The grinding apparatus according to claim 1, characterized in that, The polishing apparatus includes a control unit configured to change the polishing rate by changing at least one of the polishing conditions, the polishing conditions including changing the pressure applied to the substrate surface by the polishing head, the rotational speed of the polishing head, the rotational speed of the substrate, the amount of polishing liquid supplied by the polishing head to the substrate, and the horizontal movement speed of the polishing head relative to the substrate.

6. The grinding apparatus according to claim 1, characterized in that, The polishing stage is also provided with a sacrificial ring surrounding the substrate, the height of which is adjustable relative to the substrate surface to keep the height of the sacrificial ring relative to the substrate surface constant.

7. The grinding apparatus according to claim 6, characterized in that, A piezoelectric ceramic is mounted below the sacrificial ring, and the piezoelectric ceramic is configured to adjust the height of the sacrificial ring to keep the height of the sacrificial ring relative to the surface of the substrate constant.

8. The grinding apparatus according to claim 6, characterized in that, The polishing table is also provided with a polishing table base that supports the substrate. The polishing table base is raised and lowered in sync with the substrate to keep the sacrificial ring at a constant height relative to the surface of the substrate.

9. The grinding apparatus according to claim 6, characterized in that, The height of the sacrificial ring relative to the substrate surface is adjusted according to the desired grinding rate of the substrate edge. If the desired grinding rate of the substrate edge is greater than the desired grinding rate of the substrate center, the sacrificial ring is lower than the substrate surface. If the desired grinding rate of the substrate edge is less than the desired grinding rate of the substrate center, the sacrificial ring is higher than the substrate surface.

10. The grinding apparatus according to claim 1, characterized in that, The substrate is quadrilateral or circular.

11. The grinding apparatus according to claim 1, characterized in that, The grinding head is configured to apply a corresponding pressure to the substrate based on the film thickness of each region, wherein the film thickness is positively correlated with the pressure.

12. The grinding apparatus according to claim 10, characterized in that, At least one of the grinding head and the polishing table is provided with an airbag, which is configured to change the downward pressure applied by the grinding head to the substrate surface by changing the air pressure in the airbag, and the pressure applied by the grinding head to the substrate surface is positively correlated with the air pressure in the airbag.

13. The grinding apparatus according to claim 12, characterized in that, The grinding head also includes a grinding head base, and the airbag is installed between the grinding head base and the polishing pad.

14. The grinding apparatus according to claim 12, characterized in that, The polishing table includes a polishing table base, and the airbag is disposed between the substrate and the polishing table base.

15. The grinding apparatus according to claim 6, characterized in that, The sacrificial ring covers an area extending outward from the outer contour of the substrate by a predetermined length.

16. The grinding apparatus according to claim 15, characterized in that, The sacrificial ring at least covers a circular area extending at least 1 cm from the maximum dimension of the outer contour of the substrate.

17. The grinding apparatus according to claim 1, characterized in that, The area of ​​the polishing pad is 1 / 10 to 1 / 2 of the area of ​​the substrate.

18. The grinding apparatus according to claim 1, characterized in that, The grinding apparatus includes a film thickness measuring device for detecting the film thickness on the substrate surface to obtain the film thickness distribution.

19. A grinding apparatus for removing a surface film from a quadrilateral substrate, characterized in that, include: A polishing table for holding and rotating the substrate; The grinding head is provided with a polishing pad that contacts and presses against the substrate to grind the surface film of the substrate; The control unit is configured to adjust the grinding conditions based on the area inside and outside the inscribed circle of the grinding head relative to the substrate to control the grinding rate inside and outside the inscribed circle, wherein the grinding head is in the area inside the inscribed circle under a first grinding condition, and the grinding head is outside the area outside the inscribed circle under a second grinding condition, and the first grinding condition is different from the second grinding condition.

20. The grinding apparatus according to claim 19, characterized in that, The grinding rate is the same inside and outside the inscribed circular area.

21. The grinding apparatus according to claim 19, characterized in that, Each polishing condition includes the pressure applied by the polishing head to the substrate surface, the rotational speed of the polishing head, the rotational speed of the substrate, the amount of polishing liquid supplied by the polishing head to the substrate, and the horizontal movement speed of the polishing head relative to the substrate, wherein at least one of the first polishing conditions is different from the second polishing condition.

22. The grinding apparatus according to claim 21, characterized in that, The distance between the projection point of the center of the grinding head onto the plane of the substrate and the center of the substrate, and the relative horizontal moving speed of the grinding head and the substrate, satisfy the following formula: When 0 ≤ r ≤ b, V = V0; When b < r < a when hour, Where r is the distance between the projection point of the center of the grinding head on the plane of the substrate and the center of the substrate, V0 is the preset initial speed, a is half the side length of the substrate, and b is the radius of the polishing pad on the grinding head; a circle with the center of the substrate as the center and the distance between the projection point of the center of the grinding head on the plane of the substrate and the center of the substrate as the radius intersects the edge of the substrate at multiple intersection points, and θ is the angle between the line connecting one of the intersection points to the center of the substrate and the line connecting the vertex adjacent to the intersection point to the center of the substrate.

23. The grinding apparatus according to claim 19, characterized in that, When the contact area between the grinding head and the substrate is a transition area located both inside and outside the inscribed circle area, the control unit is further configured to obtain the ratio coefficients of the first grinding condition and the second grinding condition based on the ratio of the area of ​​the polishing pad inside and outside the inscribed circle area to the total area of ​​the polishing pad, and to obtain the grinding condition of the transition area by combining the first grinding condition and the second grinding condition with different ratio coefficients, and to adjust the grinding rate according to the obtained grinding condition of the transition area.

24. The grinding apparatus according to claim 19, characterized in that, The polishing table is also equipped with a polishing pad dresser that rotates synchronously with the substrate. The polishing pad dresser is located in the non-substrate area between the inscribed circle and the circumscribed circle of the quadrilateral substrate. When the polishing pad grinds the area outside the inscribed circle of the substrate, the polishing pad simultaneously contacts the substrate and the polishing pad dresser to dress the polishing pad while grinding the substrate.

25. The grinding apparatus according to claim 24, characterized in that, The polishing pad trimmer is configured to move up and down between a waiting position and a trimming position. When the polishing pad is outside the tangent circle area of ​​the polishing pad grinding substrate, if the polishing pad needs trimming, the polishing pad trimmer moves to the trimming position; if the polishing pad does not need trimming, the polishing pad trimmer moves to the waiting position.

26. The grinding apparatus according to claim 19, characterized in that, The substrate has multiple specific regions in the circumferential and / or radial directions of the substrate, which are determined according to the film thickness distribution on the substrate surface. During the grinding process, the substrate is rotated, and the grinding head is configured with a grinding rate according to the film thickness of each specific region, wherein the film thickness is positively correlated with the grinding rate.

27. The grinding apparatus according to claim 1 or 19, characterized in that, It also includes a conveyor, and there are multiple polishing tables. The conveyor rotates to engage the substrate and transfer the engaged substrate between the multiple polishing tables.

28. The grinding apparatus according to claim 27, characterized in that, The grinding head includes at least a first grinding head for removing a first film material from the surface of the substrate and a second grinding head for removing a second film material from the surface of the substrate. The plurality of polishing tables includes at least a second polishing table and a third polishing table. The conveying member is configured to transfer the substrate with the first film material removed from the surface of the substrate from the second polishing table to the third polishing table after the first grinding head removes the first film material from the surface of the substrate, so that the substrate on the third polishing table has the second film material removed by the second grinding head.

29. The grinding apparatus according to claim 28, characterized in that, The plurality of polishing tables also include a first polishing table and a fourth polishing table for loading and unloading the substrate, respectively. The transfer member is configured to transfer the substrate from the third polishing table to the fourth polishing table after the second grinding head removes the second film material from the surface of the substrate so that the substrate is unloaded from the fourth polishing table. The plurality of polishing tables are evenly distributed in the same circumferential direction.

30. The grinding apparatus according to claim 28, characterized in that, The plurality of polishing tables also includes a fifth polishing table for loading and unloading. The conveyor is configured to transfer the substrate with the second film material removed from the surface of the substrate from the third polishing table to the fifth polishing table after the second grinding head removes the second film material, so that the substrate is unloaded from the fifth polishing table. The plurality of polishing tables are evenly distributed in the same circumferential direction.

31. The grinding apparatus according to claim 19, characterized in that, The grinding apparatus also includes a cleaning mechanism for cleaning the substrate surface after each film removal.

32. The grinding apparatus according to claim 1 or 19, characterized in that, The number of grinding heads is at least two, and each grinding head is used to remove different film materials from the substrate surface.

33. The grinding apparatus according to claim 1 or 19, characterized in that, The polishing table is placed horizontally with the grinding head or at a certain angle relative to the horizontal plane.

34. The grinding apparatus according to claim 1 or 19, characterized in that, The grinding head is positioned above the substrate.

35. The grinding apparatus according to claim 1 or 19, characterized in that, The grinding head is disposed below the substrate.

36. A grinding apparatus, characterized in that, The invention includes an electrochemical polishing apparatus and a grinding apparatus as described in any one of claims 1-35, wherein the grinding apparatus is configured to perform a CMP process on the substrate after the substrate has undergone SFP treatment by the electrochemical polishing apparatus.

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