Grinding device

Abstract

The invention relates to a grinding device. The polishing device is provided with a three-axis sensor which is disposed adjacent to the head arm (20) and detects information on forces acting on the polishing head (1) in the three-axis direction.

Description

Technical Field

[0001] The invention relates to a grinding device. Background Art

[0002] Chemical Mechanical Polishing (CMP) is a well-known technique in the process of manufacturing semiconductor devices. A polishing device for performing CMP includes a polishing table that supports a polishing pad and a polishing head that holds a wafer.

[0003] When using such a grinding device to grind a wafer, the wafer is held by a grinding head, and the wafer is pressed with a predetermined pressure relative to the grinding surface of the grinding pad. At this time, by making the grinding table and the grinding head move relative to each other, the wafer slides in contact with the grinding surface to grind the surface of the wafer.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2021-091090

[0007] Problem that the invention aims to solve

[0008] When grinding a wafer, friction is generated between the wafer and the grinding pad. By monitoring this friction, the pressing force of the grinding head can be controlled, or the grinding end point of the wafer can be determined. For example, when grinding a wafer with a stacked upper film and a lower film, the lower film will be exposed when the upper film is removed by grinding. By monitoring the friction, the time when the lower film is exposed can be determined as the grinding end point.

[0009] The torque current of the table motor that rotates the polishing table changes according to the friction force generated between the wafer and the polishing pad. There is a method to determine the friction force based on the change of the torque current, but this method has a large error range of the current due to the difference in motor models and the assembly deviation of the polishing head. As a result, it may not be possible to accurately determine the friction force generated between the wafer and the polishing pad. Summary of the invention

[0010] Therefore, an object of the present invention is to provide a polishing device that can accurately determine the friction force generated between a wafer and a polishing pad.

[0011] (Methods of solving the problem)

[0012] One method provides a grinding device, comprising: a grinding table, which supports a grinding pad; a grinding head, which presses a substrate against the grinding table; a head shaft, which is connected to the grinding head; a head support arm, which supports the head shaft so as to be able to rotate; and a three-axis sensor, which is arranged adjacent to the head support arm and detects information related to the forces in the three-axis directions acting on the grinding head.

[0013] In one embodiment, the polishing device includes a control device electrically connected to the three-axis sensor, and during polishing of the substrate, the control device monitors a friction force generated between the substrate and the polishing head calculated based on a signal sent from the three-axis sensor.

[0014] In one embodiment, the control device measures the slope of the substrate based on the signal transmitted from the three-axis sensor, and controls the posture of the polishing head based on the measured slope of the substrate.

[0015] In one embodiment, the control device compares the calculated friction force with a predetermined threshold value, and determines an end point of polishing the substrate when the friction force reaches the threshold value.

[0016] In one embodiment, the grinding device includes a local load applying device electrically connected to the control device, which applies a local load to a portion of the retaining ring of the grinding head. The control device calculates the friction force generated between the substrate and the grinding head based on the signal sent from the three-axis sensor, and controls the operation of the local load applying device based on the calculated friction force.

[0017] One method provides a grinding device, comprising: a grinding table, which supports a grinding pad; a grinding head, which presses a substrate against the grinding table; a head shaft, which is connected to the grinding head; a head support arm, which supports the head shaft so that it can rotate; a first frame plate and a second frame plate, which are arranged on both sides of the head support arm; a first sensor group, which is arranged between the first frame plate and the head support arm and detects information related to the force acting on the grinding head; and a second sensor group, which is arranged between the second frame plate and the head support arm and detects information related to the force acting on the grinding head.

[0018] In one embodiment, each of the first sensor group and the second sensor group includes a plurality of force sensors, and the plurality of force sensors are arranged at positions equidistant from the head shaft.

[0019] In one embodiment, the polishing device includes a control device that is electrically connected to the first sensor group and the second sensor group. During the polishing of the substrate, the control device monitors the friction force generated between the substrate and the polishing head calculated based on signals sent from the first sensor group and the second sensor group.

[0020] In one embodiment, the control device measures the slope of the substrate based on the signals transmitted from the first sensor group and the second sensor group, and controls the posture of the polishing head based on the measured slope of the substrate.

[0021] In one embodiment, the control device compares the calculated friction force with a predetermined threshold value, and determines an end point of polishing the substrate when the friction force reaches the threshold value.

[0022] In one embodiment, the grinding device includes a local load applying device electrically connected to the control device, which applies a local load to a portion of the retaining ring of the grinding head. The control device calculates the friction force generated between the substrate and the grinding head based on the signals sent from the first sensor group and the second sensor group, and controls the operation of the local load applying device based on the calculated friction force.

[0023] (Effects of the Invention)

[0024] The polishing device is equipped with a sensor for detecting information about the force acting on the polishing head. Therefore, the polishing device can accurately determine the friction force generated between the wafer held by the polishing head and the polishing pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a figure which shows one embodiment of a grinding|polishing apparatus.

[0026] Figure 2 It is a diagram showing the first sensor group and the second sensor group.

[0027] Figure 3 This is a diagram showing an example of components of frictional force acting between a polishing head and a wafer.

[0028] Figure 4 It is a graph showing the change of friction force.

[0029] Figure 5 This is a diagram showing an example of components of frictional force acting between a polishing head and a wafer.

[0030] Figure 6 This is a diagram showing a state where a wafer is tilted relative to a polishing pad.

[0031] Figure 7It is a diagram showing another embodiment of the polishing device. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0033] Figure 1 is a diagram showing one embodiment of a grinding device. Figure 1 As shown, the polishing device comprises: a polishing table 3 supporting a polishing pad 2; a polishing head 1 pressing a wafer W (substrate, etc.) having a film against the polishing pad 2; a table motor 6 rotating the polishing table 3; a polishing liquid supply nozzle 5 for supplying a polishing liquid such as slurry onto the polishing pad 2; and a control device 9 for controlling the operation of the polishing device. The upper surface of the polishing pad 2 constitutes a polishing surface 2a for polishing the wafer W. The control device 9 is electrically connected to the table motor 6.

[0034] The polishing head 1 is connected to a head shaft 10, and the head shaft 10 is connected to a polishing head motor (not shown) via a connection mechanism such as a belt. The polishing head motor rotates the polishing head 1 together with the head shaft 10 in the direction indicated by the arrow.

[0035] The head shaft 10 is connected to a head support arm 20 that supports the head shaft 10 so as to be rotatable, and is configured to be movable up and down relative to the head support arm 20 by an up and down moving mechanism (not shown). The head support arm 20 is connected to an arm shaft 21 and can rotate around the arm shaft 21. The grinding table 3 is connected to a table motor 6, and the table motor 6 is configured to rotate the grinding table 3 and the grinding pad 2 in the direction indicated by the arrow.

[0036] The wafer W is ground as follows. The grinding table 3 and the grinding head 1 are placed in Figure 1 The polishing head 1 rotates in the direction indicated by the arrow, and supplies the polishing liquid from the polishing liquid supply nozzle 5 to the polishing surface 2a of the polishing pad 2 on the polishing table 3. The wafer W is rotated around the head shaft 10 by the polishing head 1, and the wafer W is pressed against the polishing surface 2a of the polishing pad 2 by the polishing head 1 in the state where the polishing liquid exists on the polishing pad 2. The polishing table 3 rotates around its center CP. The surface of the wafer W is polished by the chemical action of the polishing liquid and the mechanical action of the abrasive grains contained in the polishing liquid or the polishing pad 2.

[0037] The control device 9 is composed of at least one computer. The control device 9 includes: a storage device 9a storing a program; and a computing device 9b that performs operations according to the commands included in the program. The computing device 9b includes a CPU (central processing unit) or a GPU (graphics processing unit) that performs operations according to the commands included in the program stored in the storage device 9a. The storage device 9a includes: a main storage device (such as a random access memory) that can be accessed by the computing device 9b; and an auxiliary storage device (such as a hard disk drive or a solid state drive) that stores data and programs.

[0038] In order to accurately control the pressing force of the polishing head 1 or accurately determine the polishing end point of the wafer W, it is important to accurately determine the friction force generated between the wafer W and the polishing pad 2. Therefore, the polishing device of this embodiment includes a first sensor group 30 and a second sensor group 31 arranged adjacent to the head support arm 20 in order to accurately determine the friction force. The configuration of these sensor groups 30 and 31 will be described below with reference to the drawings.

[0039] Figure 2 is a diagram showing a first sensor group and a second sensor group. Figure 2 As shown, the first sensor group 30 and the second sensor group 31 are respectively disposed on the front end side of the head support arm 20 (ie, the connection side of the head shaft 10 ).

[0040] The grinding device has two sides ( Figure 2 In the illustrated embodiment, a first frame plate 25A and a second frame plate 25B are provided above and below the head support arm 20 . Figure 1 In order to facilitate viewing of the figure, these frame plates 25A and 25B are omitted. However, even in Figure 1 In the illustrated embodiment, the grinding device is still provided with frame plates 25A, 25B.

[0041] The frame plates 25A and 25B have the same structure and are respectively in the shape of a flat plate extending parallel to the head support arm 20. The first frame plate 25A is disposed below the head support arm 20, and the second frame plate 25B is disposed above the head support arm 20.

[0042] like Figure 2 As shown in FIG. 1 , the first sensor group 30 is disposed between the first frame plate 25A and the head support arm 20, and is configured to detect information about the force acting on the grinding head 1. More specifically, the first sensor group 30 includes a plurality of force sensors 30A, 30B, and 30C. These force sensors 30A, 30B, and 30C are disposed around the head shaft 10 and are disposed at positions equidistant from the head shaft 10 (see FIG. 1 ). Figure 1 and Figure 2 The force sensors 30A, 30B, and 30C are arranged on the same plane above the first frame plate 25A.

[0043] The second sensor group 31 has the same structure as the first sensor group 30. The second sensor group 31 is arranged between the second frame plate 25B and the head support arm 20, and is configured to detect information about the force acting on the grinding head 1. More specifically, the second sensor group 31 includes a plurality of force sensors 31A, 31B, and 31C. These force sensors 31A, 31B, and 31C are arranged around the head shaft 10 and are arranged at positions equidistant from the head shaft 10 (see FIG. 2 ). Figure 1 and Figure 2 The force sensors 31A, 31B, and 31C are arranged on the same plane below the second frame plate 25B.

[0044] Figure 1 and Figure 2 In the embodiment shown, the first sensor group 30 and the second sensor group 31 each include three force sensors, but the number of force sensors is not limited to this embodiment. The number of force sensors may also be determined according to the size of the polishing head 1 and the pressing force of the polishing head 1. In one embodiment, the first sensor group 30 and the second sensor group 31 may each include at least one force sensor.

[0045] Figure 1 and Figure 2 In the illustrated embodiment, force sensors 30A, 30B, 30C (and force sensors 31A, 31B, 31C) are three-axis sensors that detect information about forces acting on the grinding head 1 in three-axis directions (i.e., x-axis, y-axis, and z-axis). An example of a three-axis sensor is a crystal piezoelectric element. Here, the x-axis direction and the y-axis direction are directions extending perpendicularly to the head shaft 10 (i.e., directions extending parallel to the grinding pad 2), and in the present embodiment, they are horizontal directions. The z-axis direction is a direction extending parallel to the head shaft 10 (i.e., a direction extending perpendicularly to the grinding pad 2), and in the present embodiment, it is a vertical direction.

[0046] In one embodiment, each of the force sensors 30A, 30B, 30C (and the force sensors 31A, 31B, 31C) may be a two-axis sensor that detects information about the force in two-axis directions (i.e., the x-axis and the y-axis), or may be a single-axis sensor that detects information about the force in a single-axis direction (i.e., the z-axis). In one embodiment, each of the force sensors 30A, 30B, 30C (and the force sensors 31A, 31B, 31C) may be a combination of a two-axis sensor and a single-axis sensor. Even with such a configuration, the grinding device can still accurately determine the friction force.

[0047] like Figure 2 As shown, the head shaft 10 passes through a through hole formed in the center of the frame plates 25A and 25B. The grinding device includes a first bearing 26A disposed between the head shaft 10 and the first frame plate 25A, and a second bearing 26B disposed between the head shaft 10 and the second frame plate 25B.

[0048] The bearings 26A and 26B are respectively configured to bear the load (more specifically, the radial load and the axial load (i.e., the thrust load)) of the polishing head 1 through the head shaft 10. When the polishing head 1 presses the wafer W against the polishing pad 2, the load of the polishing head 1 acts on the force sensors 30A, 30B, 30C, 31A, 31B, and 31C, respectively.

[0049] The grinding device of this embodiment has a structure in which the head shaft 10 is supported by the frame plates 25A, 25B (and the bearings 26A, 26B), and has a structure in which the sensor groups 30, 31 are sandwiched between the frame plates 25A, 25B and the head support arm 20. With this structure, the grinding device can evenly transmit the load acting on the grinding head 1 to each sensor group 30, 31 via the head shaft 10.

[0050] By arranging a plurality of force sensors in the space formed above and below the head support arm 20, a force sensor having a compact size can be used, and as a result, the space saving of the grinding device can be achieved. Furthermore, with this configuration, a plurality of force sensors having a compact size and a high resolution can be used, and as a result, information on the force acting on the grinding head 1 can be detected more accurately.

[0051] The control device 9 is electrically connected to each of the force sensors 30A, 30B, 30C, 31A, 31B, and 31C. The control device 9 calculates the load of the polishing head 1 based on the signals detected by each of the force sensors 30A, 30B, 30C, 31A, 31B, and 31C, and calculates the friction force F acting on the wafer W based on the calculated load of the polishing head 1. Figure 2 As shown, the friction force F is the sum of the absolute value of the force component FL acting on the force sensors 30A, 30B, and 30C and the absolute value of the force component FU acting on the force sensors 31A, 31B, and 31C (F=|FL|+|FU|).

[0052] Figure 3 This is an example diagram showing the components of the friction force acting between the polishing head and the wafer. Figure 3 As shown in the figure, when the polishing head 1 is viewed from above, the component of the force acting on the force sensors 30A, 30B, 30C, 31A, 31B, and 31C in the x-axis direction is defined as f x1 、f x2 、f x3 、f x4 、f x5 、f x6 , and define the component in the y-axis direction as f y1 、f y2 、f y3 、f y4 、f y5 、f y6 .

[0053] The component FxL of the force acting on the force sensors 30A, 30B, and 30C in the x-axis direction is expressed as f x1 +f x2 +f x3 To express it, the component FyL in the y-axis direction is expressed as f y1 +f y2 +f y3 The component FxU of the force acting on the force sensors 31A, 31B, and 31C in the x-axis direction is expressed as f x4 +f x5 +f x6 To express it, the component FyU in the y-axis direction is expressed as f y4 +f y5 +f y6 To show.

[0054] In the x-axis and y-axis directions perpendicular to each other, the composite component F of the force acting on the force sensors 30A, 30B, 30C and the force sensors 31A, 31B, 31C (i.e., the friction force generated between the polishing pad 2 and the wafer W) is expressed by the following formula 1.

[0055] [Mathematical formula 1]

[0056] Formula 1: F = √F 2 xL+F 2 yL+F 2 xU+F 2 yU

[0057] The control device 9 stores data related to the above formula 1 in the storage device 9a. Therefore, the control device 9 calculates the friction force F based on the signals sent by each force sensor belonging to the sensor group 30, 31 and the above formula 1. The control device 9 can also monitor the calculated friction force F at any time during the polishing of the wafer W. By monitoring the friction force F, the control device 9 can accurately determine the polishing end point of the wafer W according to the change of the friction force F.

[0058] Figure 4 It is a graph showing the change of friction force. Figure 4 In the embodiment shown, the wafer W has a stacked upper film and a lower film. Since the upper film is made of a softer material than the lower film, the friction force generated between the upper film and the polishing pad 2 is smaller than the friction force generated between the lower film and the polishing pad 2. When the wafer W is continuously polished, the upper film is removed soon and the lower film is exposed. Figure 4 As shown in the graph, the friction force F changes when the lower film is exposed. In addition, Figure 4 The graph of is a graph showing the time variation of the friction force F.

[0059] The control device 9 can determine the polishing end point (i.e., the time when the lower film is exposed) by monitoring the friction force F during the polishing of the wafer W. More specifically, the control device 9 stores a threshold value according to the type of film of the wafer W to be polished in the storage device 9a. The threshold value is a value equivalent to the friction force at the polishing end point. The control device 9 compares the calculated friction force F with a predetermined threshold value, and determines the polishing end point of the wafer W when the current friction force F reaches the threshold value.

[0060] Figure 4 In the embodiment shown, since the upper film is made of a softer material than the lower film, the friction force F increases as the polishing of the wafer W proceeds. However, depending on the type of wafer W, the upper film may be made of a harder material than the lower film. In this case, the friction force F decreases as the polishing of the wafer W proceeds. Even in this case, the control device 9 still compares the calculated friction force F with a predetermined threshold value, and determines the polishing end point of the wafer W when the current friction force F reaches the predetermined threshold value.

[0061] The control device 9 can also determine the friction force based on the change in the torque current of the table motor 6, but it may not be possible to accurately determine the friction force due to differences in motor models and assembly deviations of the polishing head 1. In the present embodiment, the control device 9 determines the friction force F based on a force sensor that detects information about the force acting on the polishing head 1. Therefore, the control device 9 can accurately determine the friction force F generated between the wafer W held by the polishing head 1 and the polishing pad 2.

[0062] Figure 5 This is an example diagram showing the components of the friction force acting between the polishing head and the wafer. Figure 5 As shown in FIG. 1 , the component of the force acting on the force sensors 30A, 30B, 30C, 31A, 31B, and 31C in the z-axis direction is defined as f z1 、f z2 、f z3 、f z4 、f z5 、f z6 The component of the force acting on the force sensors 30A, 30B, 30C, 31A, 31B, 31C in the z-axis direction (that is, the vertical resistance) N is expressed as f z1 +f z2 +f z3 +f z4 +f z5 +f z6 To express (N = f z1 +f z2 +f z3 +f z4 +f z5 +f z6 ).

[0063] The friction force F generated between the polishing pad 2 and the wafer W is expressed by the following formula 2.

[0064] Formula 2: F = μ × N

[0065] Here, μ represents the friction coefficient. The friction coefficient μ varies depending on the type of wafer W, and furthermore, it changes even during the polishing of the wafer W. Therefore, the control device 9 can also determine (estimate) the friction coefficient μ as an arbitrary value, and determine the friction force F based on the determined friction coefficient μ and the vertical resistance N. Even in this way, the control device 9 can still accurately determine the friction force F.

[0066] The force sensors 30A, 30B, 30C, 31A, 31B, and 31C of this embodiment are three-axis sensors. Therefore, the control device 9 can derive the friction coefficient μ from the above formula 2 by deriving the friction force F from the above formula 1 and calculating the vertical resistance N. The control device 9 can obtain a more accurate friction force F based on the friction coefficient μ and the vertical resistance N.

[0067] Since the above formula 2 includes the friction coefficient μ, a proportional relationship corresponding to the friction coefficient μ is established between the above formula 1 and the above formula 2. Therefore, the control device 9 can judge the abnormality of the force sensor (and / or the assembly abnormality of the grinding head 1) by comparing the friction force F derived from the formula 1 and the friction force F derived from the formula 2. More specifically, the control device 9 compares the two friction forces F derived from the above formula 1 and the formula 2 during the grinding of the wafer W. When the proportional relationship between the two friction forces F is not established, it can also be determined that at least one of the force sensors 30A, 30B, 30C, 31A, 31B, 31C has an abnormality.

[0068] Figure 6 : is a diagram showing the situation where the wafer is tilted relative to the polishing pad. Figure 6 As shown, during the polishing of the wafer W, the wafer W is tilted relative to the polishing pad 2. When the wafer W is polished continuously in this state, not only the uniformity of the film thickness of the wafer W is reduced, but also the polishing end point of the wafer W may not be accurately determined. More specifically, when the wafer W is tilted, the upper film cannot be polished uniformly, and a portion of the lower film may be exposed in a state where the upper film partially remains. At this time, because the wafer W is polished in a mixed state of a portion of the upper film and a portion of the lower film, the friction force F changes steadily with the passage of time, and even when the friction force F reaches the threshold, the wafer W may not have reached the polishing end point.

[0069] Therefore, the control device 9 can also calculate the vertical resistance N acting on each force sensor based on the signals sent from the force sensors 30A, 30B, 30C, 31A, 31B, and 31C, and measure the slope of the wafer W from the vertical resistance N. By arranging a plurality of force sensors belonging to the sensor groups 30 and 31 around the head shaft 10, the control device 9 can accurately measure the slope of the wafer W.

[0070] The control device 9 can also control the posture of the polishing head 1 based on the measured slope of the wafer W. The polishing head 1 includes an elastic membrane (not shown) for pressing the wafer W against the polishing surface 2a of the polishing pad 2. Therefore, the control device 9 can also supply compressed gas to the elastic membrane and control the posture of the polishing head 1 in a manner that the polishing head 1 and the polishing pad 2 are parallel.

[0071] Furthermore, when this embodiment is adopted, the control device 9 can determine whether the pressing force of the polishing head 1 acting on the entire wafer W is uniform based on the signals sent from each of the plurality of force sensors. When the signals sent from the force sensors are different, the control device 9 can determine that the pressing force of the polishing head 1 is not uniform. At this time, the control device 9 can also supply compressed gas to the elastic membrane and control the pressing force of the polishing head 1 so that the pressing force of the polishing head 1 becomes uniform.

[0072] Figure 7 It is a diagram showing another embodiment of the polishing device. Figure 7 In the embodiment shown, the grinding head 1 is provided with a retaining ring 40 surrounding the wafer W. Figure 7 As shown, the grinding apparatus includes a first local load applying device 50A for applying a local load to a portion of the retaining ring 40 , and a second local load applying device 50B for applying a local load to a portion of the retaining ring 40 .

[0073] The local load applying devices 50A and 50B are arranged above the retaining ring 40 and fixed to the head support arm 20. Therefore, the retaining ring 40 rotates around its axis during grinding, while the local load applying devices 50A and 50B are stationary and do not rotate integrally with the retaining ring 40.

[0074] The first local load applying device 50A is arranged on the upstream side of the retaining ring 40 (the side of the retaining ring 40 where the polishing liquid flows into the polishing surface 2a) in the traveling direction of the polishing surface 2a of the polishing pad 2, and the second local load applying device 50B is arranged on the downstream side of the retaining ring 40 (the opposite side of the retaining ring 40 where the polishing liquid flows out of the polishing surface 2a) in the traveling direction of the polishing surface 2a of the polishing pad 2. The control device 9 is electrically connected to the local load applying devices 50A and 50B, respectively, and the local load applying devices 50A and 50B respectively apply a downward local load to a part of the retaining ring 40.

[0075] When the polishing liquid flows between the wafer W and the polishing pad 2, the friction force generated between the wafer W and the polishing pad 2 may be different between the upstream side and the downstream side of the retaining ring 40. The friction force acting on the wafer W should be uniform across the entire wafer W. Therefore, the control device 9 can also calculate the friction force F acting on the entire wafer W based on the signals sent from each of the plurality of force sensors, and control the respective actions of the local load imparting devices 50A and 50B when the friction force F between the upstream side and the downstream side of the retaining ring 40 is different. With this configuration, the control device 9 can make the friction force acting on the entire wafer W uniform and maintain the friction force constant.

[0076] The above-mentioned embodiments are recorded for the purpose of enabling persons with general knowledge in the technical field to which the present invention belongs to implement the present invention. Those skilled in the art can certainly form various variations of the above-mentioned embodiments, and the technical ideas of the present invention can also be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is interpreted in the broadest scope of the technical ideas defined by the scope of the patent application.

[0077] Industrial Applicability

[0078] The present invention can be used in a grinding device.

[0079] Explanation of symbols

[0080] 1: Grinding head

[0081] 2: Polishing pad

[0082] 2a: Grinding surface

[0083] 3: Grinding table

[0084] 5: Grinding fluid supply nozzle

[0085] 6: Motor

[0086] 9: Control device

[0087] 9a: Storage Device

[0088] 9b: Computing Device

[0089] 10: Head shaft

[0090] 20: Head support arm

[0091] 25A: First rack plate

[0092] 25B: Second rack plate

[0093] 30: First sensor group

[0094] 30A, 30B, 30C: Force sensor

[0095] 31: Second sensor group

[0096] 31A, 31B, 31C: Force sensor

[0097] 40: retaining ring

[0098] 50A: First local load imparting device

[0099] 50B: Second local load imparting device.

Claims

1. A grinding device, characterized in that: have: a grinding table supporting a grinding pad; a grinding head, the grinding head pressing the substrate against the grinding table; A head shaft connected to the grinding head; a head support arm, the head support arm rotatably supporting the head shaft; and A three-axis sensor is disposed adjacent to the head support arm and detects information related to forces acting on the grinding head in three-axis directions.

2. The grinding device according to claim 1, characterized in that The grinding device includes a control device, which is electrically connected to the three-axis sensor. During polishing of the substrate, the control device monitors a friction force generated between the substrate and the polishing head calculated based on a signal transmitted from the three-axis sensor.

3. The grinding device according to claim 2, characterized in that The control device measures the slope of the substrate based on the signal sent from the three-axis sensor, The posture of the polishing head is controlled based on the measured slope of the substrate.

4. The grinding device according to claim 2 or 3, characterized in that: The control device compares the calculated friction force with a predetermined threshold value, When the friction force reaches the threshold, the polishing endpoint of the substrate is determined.

5. The grinding device according to claim 2 or 3, characterized in that: The grinding device includes a local load applying device electrically connected to the control device, and the local load applying device applies a local load to a part of the retaining ring of the grinding head. The control device calculates the friction force generated between the substrate and the polishing head based on the signal sent from the three-axis sensor, The operation of the local load applying device is controlled based on the calculated friction force.

6. A grinding device, characterized in that: have: a grinding table supporting a grinding pad; a grinding head, the grinding head pressing the substrate against the grinding table; A head shaft connected to the grinding head; A head support arm, the head support arm supports the head shaft rod so as to be rotatable; A first frame plate and a second frame plate, wherein the first frame plate and the second frame plate are arranged on both sides of the head support arm; a first sensor group, the first sensor group being disposed between the first frame plate and the head support arm and detecting information related to a force acting on the grinding head; and The second sensor group is disposed between the second frame plate and the head support arm and detects information related to a force acting on the polishing head.

7. The grinding device according to claim 6, characterized in that The first sensor group and the second sensor group each include a plurality of force sensors. The plurality of force sensors are arranged at positions equidistant from the head shaft.

8. The grinding device according to claim 6 or 7, characterized in that: The polishing device includes a control device electrically connected to the first sensor group and the second sensor group. During polishing of the substrate, the control device monitors a friction force generated between the substrate and the polishing head calculated based on signals transmitted from the first sensor group and the second sensor group.

9. The grinding device according to claim 8, characterized in that The control device measures the slope of the substrate based on the signals sent from the first sensor group and the second sensor group. The posture of the polishing head is controlled based on the measured slope of the substrate.

10. The grinding device according to claim 8, characterized in that The control device compares the calculated friction force with a predetermined threshold value, When the friction force reaches the threshold, the polishing endpoint of the substrate is determined.

11. The grinding device according to claim 8, characterized in that: The grinding device includes a local load applying device electrically connected to the control device, and the local load applying device applies a local load to a part of the retaining ring of the grinding head. The control device calculates the friction force generated between the substrate and the polishing head based on the signals sent from the first sensor group and the second sensor group. The operation of the local load applying device is controlled based on the calculated friction force.

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